diff --git a/app/assets/javascripts/alert_management/components/alert_details.vue b/app/assets/javascripts/alert_management/components/alert_details.vue
index 99194007551..6abdbc6be98 100644
--- a/app/assets/javascripts/alert_management/components/alert_details.vue
+++ b/app/assets/javascripts/alert_management/components/alert_details.vue
@@ -230,7 +230,7 @@ export default {
           :aria-label="__('Toggle sidebar')"
           category="primary"
           variant="default"
-          class="d-sm-none position-absolute toggle-sidebar-mobile-button"
+          class="d-sm-none gl-absolute toggle-sidebar-mobile-button"
           type="button"
           @click="toggleSidebar"
         >
diff --git a/app/assets/javascripts/alert_management/components/alert_sidebar.vue b/app/assets/javascripts/alert_management/components/alert_sidebar.vue
index 2d647ad296a..e1fd3e7fd24 100644
--- a/app/assets/javascripts/alert_management/components/alert_sidebar.vue
+++ b/app/assets/javascripts/alert_management/components/alert_sidebar.vue
@@ -1,14 +1,18 @@
 <script>
+import glFeatureFlagsMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 import SidebarHeader from './sidebar/sidebar_header.vue';
 import SidebarTodo from './sidebar/sidebar_todo.vue';
 import SidebarStatus from './sidebar/sidebar_status.vue';
+import SidebarAssignees from './sidebar/sidebar_assignees.vue';
 
 export default {
   components: {
+    SidebarAssignees,
     SidebarHeader,
     SidebarTodo,
     SidebarStatus,
   },
+  mixins: [glFeatureFlagsMixin()],
   props: {
     sidebarCollapsed: {
       type: Boolean,
@@ -28,11 +32,6 @@ export default {
       return this.sidebarCollapsed ? 'right-sidebar-collapsed' : 'right-sidebar-expanded';
     },
   },
-  methods: {
-    handleAlertSidebarError(errorMessage) {
-      this.$emit('alert-sidebar-error', errorMessage);
-    },
-  },
 };
 </script>
 
@@ -48,7 +47,14 @@ export default {
         :project-path="projectPath"
         :alert="alert"
         @toggle-sidebar="$emit('toggle-sidebar')"
-        @alert-sidebar-error="handleAlertSidebarError"
+        @alert-sidebar-error="$emit('alert-sidebar-error', $event)"
+      />
+      <sidebar-assignees
+        v-if="glFeatures.alertAssignee"
+        :project-path="projectPath"
+        :alert="alert"
+        @toggle-sidebar="$emit('toggle-sidebar')"
+        @alert-sidebar-error="$emit('alert-sidebar-error', $event)"
       />
       <!-- TODO: Remove after adding extra attribute blocks to sidebar -->
       <div class="block"></div>
diff --git a/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignee.vue b/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignee.vue
new file mode 100644
index 00000000000..df07038151e
--- /dev/null
+++ b/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignee.vue
@@ -0,0 +1,51 @@
+<script>
+import { GlDropdownItem } from '@gitlab/ui';
+
+export default {
+  components: {
+    GlDropdownItem,
+  },
+  props: {
+    user: {
+      type: Object,
+      required: true,
+    },
+    active: {
+      type: Boolean,
+      required: true,
+    },
+  },
+  methods: {
+    isActive(name) {
+      return this.alert.assignees.nodes.some(({ username }) => username === name);
+    },
+  },
+};
+</script>
+
+<template>
+  <gl-dropdown-item
+    :key="user.username"
+    data-testid="assigneeDropdownItem"
+    class="assignee-dropdown-item gl-vertical-align-middle"
+    :active="active"
+    active-class="is-active"
+    @click="$emit('update-alert-assignees', user.username)"
+  >
+    <span class="gl-relative mr-2">
+      <img
+        :alt="user.username"
+        :src="user.avatar_url"
+        :width="32"
+        class="avatar avatar-inline gl-m-0 s32"
+        data-qa-selector="avatar_image"
+      />
+    </span>
+    <span class="d-flex gl-flex-direction-column gl-overflow-hidden">
+      <strong class="dropdown-menu-user-full-name">
+        {{ user.name }}
+      </strong>
+      <span class="dropdown-menu-user-username"> {{ user.username }}</span>
+    </span>
+  </gl-dropdown-item>
+</template>
diff --git a/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignees.vue b/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignees.vue
new file mode 100644
index 00000000000..358e0974026
--- /dev/null
+++ b/app/assets/javascripts/alert_management/components/sidebar/sidebar_assignees.vue
@@ -0,0 +1,269 @@
+<script>
+import {
+  GlIcon,
+  GlDropdown,
+  GlDropdownDivider,
+  GlDropdownHeader,
+  GlDropdownItem,
+  GlLoadingIcon,
+  GlTooltip,
+  GlButton,
+  GlSprintf,
+} from '@gitlab/ui';
+import axios from '~/lib/utils/axios_utils';
+import { s__ } from '~/locale';
+import alertSetAssignees from '../../graphql/mutations/alert_set_assignees.graphql';
+import SidebarAssignee from './sidebar_assignee.vue';
+import { debounce } from 'lodash';
+
+const DATA_REFETCH_DELAY = 250;
+
+export default {
+  FETCH_USERS_ERROR: s__(
+    'AlertManagement|There was an error while updating the assignee(s) list. Please try again.',
+  ),
+  UPDATE_ALERT_ASSIGNEES_ERROR: s__(
+    'AlertManagement|There was an error while updating the assignee(s) of the alert. Please try again.',
+  ),
+  components: {
+    GlIcon,
+    GlDropdown,
+    GlDropdownItem,
+    GlDropdownDivider,
+    GlDropdownHeader,
+    GlLoadingIcon,
+    GlTooltip,
+    GlButton,
+    GlSprintf,
+    SidebarAssignee,
+  },
+  props: {
+    projectPath: {
+      type: String,
+      required: true,
+    },
+    alert: {
+      type: Object,
+      required: true,
+    },
+    isEditable: {
+      type: Boolean,
+      required: false,
+      default: true,
+    },
+  },
+  data() {
+    return {
+      isDropdownShowing: false,
+      isDropdownSearching: false,
+      isUpdating: false,
+      search: '',
+      users: [],
+    };
+  },
+  computed: {
+    assignedUsers() {
+      return this.alert.assignees.nodes.length > 0
+        ? this.alert.assignees.nodes[0].username
+        : s__('AlertManagement|Unassigned');
+    },
+    dropdownClass() {
+      return this.isDropdownShowing ? 'show' : 'gl-display-none';
+    },
+    userListValid() {
+      return !this.isDropdownSearching && this.users.length > 0;
+    },
+    userListEmpty() {
+      return !this.isDropdownSearching && this.users.length === 0;
+    },
+  },
+  watch: {
+    search: debounce(function debouncedUserSearch() {
+      this.updateAssigneesDropdown();
+    }, DATA_REFETCH_DELAY),
+  },
+  mounted() {
+    this.updateAssigneesDropdown();
+  },
+  methods: {
+    hideDropdown() {
+      this.isDropdownShowing = false;
+    },
+    toggleFormDropdown() {
+      this.isDropdownShowing = !this.isDropdownShowing;
+      const { dropdown } = this.$refs.dropdown.$refs;
+      if (dropdown && this.isDropdownShowing) {
+        dropdown.show();
+      }
+    },
+    isActive(name) {
+      return this.alert.assignees.nodes.some(({ username }) => username === name);
+    },
+    buildUrl(urlRoot, url) {
+      let newUrl;
+      if (urlRoot != null) {
+        newUrl = urlRoot.replace(/\/$/, '') + url;
+      }
+      return newUrl;
+    },
+    updateAssigneesDropdown() {
+      this.isDropdownSearching = true;
+      return axios
+        .get(this.buildUrl(gon.relative_url_root, '/autocomplete/users.json'), {
+          params: {
+            search: this.search,
+            per_page: 20,
+            active: true,
+            current_user: true,
+            project_id: gon.current_project_id,
+          },
+        })
+        .then(({ data }) => {
+          this.users = data;
+        })
+        .catch(() => {
+          this.$emit('alert-sidebar-error', this.$options.FETCH_USERS_ERROR);
+        })
+        .finally(() => {
+          this.isDropdownSearching = false;
+        });
+    },
+    updateAlertAssignees(assignees) {
+      this.isUpdating = true;
+      this.$apollo
+        .mutate({
+          mutation: alertSetAssignees,
+          variables: {
+            iid: this.alert.iid,
+            assigneeUsernames: [this.isActive(assignees) ? '' : assignees],
+            projectPath: this.projectPath,
+          },
+        })
+        .then(() => {
+          this.hideDropdown();
+        })
+        .catch(() => {
+          this.$emit('alert-sidebar-error', this.$options.UPDATE_ALERT_ASSIGNEES_ERROR);
+        })
+        .finally(() => {
+          this.isUpdating = false;
+        });
+    },
+  },
+};
+</script>
+
+<template>
+  <div class="block alert-status">
+    <div ref="status" class="sidebar-collapsed-icon" @click="$emit('toggle-sidebar')">
+      <gl-icon name="user" :size="14" />
+      <gl-loading-icon v-if="isUpdating" />
+      <p v-else class="collapse-truncated-title px-1">{{ assignedUsers }}</p>
+    </div>
+    <gl-tooltip :target="() => $refs.status" boundary="viewport" placement="left">
+      <gl-sprintf :message="s__('AlertManagement|Alert assignee(s): %{assignees}')">
+        <template #assignees>
+          {{ assignedUsers }}
+        </template>
+      </gl-sprintf>
+    </gl-tooltip>
+
+    <div class="hide-collapsed">
+      <p class="title gl-display-flex gl-justify-content-space-between">
+        {{ s__('AlertManagement|Assignee') }}
+        <a
+          v-if="isEditable"
+          ref="editButton"
+          class="btn-link"
+          href="#"
+          @click="toggleFormDropdown"
+          @keydown.esc="hideDropdown"
+        >
+          {{ s__('AlertManagement|Edit') }}
+        </a>
+      </p>
+
+      <div class="dropdown dropdown-menu-selectable" :class="dropdownClass">
+        <gl-dropdown
+          ref="dropdown"
+          :text="assignedUsers"
+          class="w-100"
+          toggle-class="dropdown-menu-toggle"
+          variant="outline-default"
+          @keydown.esc.native="hideDropdown"
+          @hide="hideDropdown"
+        >
+          <div class="dropdown-title">
+            <span class="alert-title">{{ s__('AlertManagement|Assign Assignees') }}</span>
+            <gl-button
+              :aria-label="__('Close')"
+              variant="link"
+              class="dropdown-title-button dropdown-menu-close"
+              icon="close"
+              @click="hideDropdown"
+            />
+          </div>
+          <div class="dropdown-input">
+            <input
+              v-model.trim="search"
+              class="dropdown-input-field"
+              type="search"
+              :placeholder="__('Search users')"
+            />
+            <gl-icon name="search" class="dropdown-input-search ic-search" data-hidden="true" />
+          </div>
+          <div class="dropdown-content dropdown-body">
+            <template v-if="userListValid">
+              <gl-dropdown-item @click="updateAlertAssignees('')">
+                {{ s__('AlertManagement|Unassigned') }}
+              </gl-dropdown-item>
+              <gl-dropdown-divider />
+
+              <gl-dropdown-header class="mt-0">
+                {{ s__('AlertManagement|Assignee(s)') }}
+              </gl-dropdown-header>
+
+              <template v-for="user in users">
+                <sidebar-assignee
+                  v-if="isActive(user.username)"
+                  :key="user.username"
+                  :user="user"
+                  :active="true"
+                  @update-alert-assignees="updateAlertAssignees"
+                />
+              </template>
+              <gl-dropdown-divider />
+              <template v-for="user in users">
+                <sidebar-assignee
+                  v-if="!isActive(user.username)"
+                  :key="user.username"
+                  :user="user"
+                  :active="false"
+                  @update-alert-assignees="updateAlertAssignees"
+                />
+              </template>
+            </template>
+            <gl-dropdown-item v-else-if="userListEmpty">
+              {{ s__('AlertManagement|No Matching Results') }}
+            </gl-dropdown-item>
+            <gl-loading-icon v-else />
+          </div>
+        </gl-dropdown>
+      </div>
+
+      <gl-loading-icon v-if="isUpdating" :inline="true" />
+      <p
+        v-else-if="!isDropdownShowing"
+        class="value gl-m-0"
+        :class="{ 'no-value': !alert.assignees.nodes }"
+      >
+        <span v-if="alert.assignees.nodes" class="gl-text-gray-700" data-testid="assigned-users">{{
+          assignedUsers
+        }}</span>
+        <span v-else>
+          {{ s__('AlertManagement|None') }}
+        </span>
+      </p>
+    </div>
+  </div>
+</template>
diff --git a/app/assets/javascripts/alert_management/components/sidebar/sidebar_header.vue b/app/assets/javascripts/alert_management/components/sidebar/sidebar_header.vue
index b1c369f54e6..047793d8cee 100644
--- a/app/assets/javascripts/alert_management/components/sidebar/sidebar_header.vue
+++ b/app/assets/javascripts/alert_management/components/sidebar/sidebar_header.vue
@@ -17,13 +17,13 @@ export default {
 </script>
 
 <template>
-  <div class="block">
-    <span class="issuable-header-text hide-collapsed float-left">
+  <div class="block  d-flex justify-content-between">
+    <span class="issuable-header-text hide-collapsed">
       {{ __('Quick actions') }}
     </span>
     <toggle-sidebar
       :collapsed="sidebarCollapsed"
-      css-classes="float-right"
+      css-classes="ml-auto"
       @toggle="$emit('toggle-sidebar')"
     />
     <!-- TODO: Implement after or as part of: https://gitlab.com/gitlab-org/gitlab/-/issues/215946 -->
diff --git a/app/assets/javascripts/alert_management/components/sidebar/sidebar_status.vue b/app/assets/javascripts/alert_management/components/sidebar/sidebar_status.vue
index 24a79a94a9a..89dbbedd9c1 100644
--- a/app/assets/javascripts/alert_management/components/sidebar/sidebar_status.vue
+++ b/app/assets/javascripts/alert_management/components/sidebar/sidebar_status.vue
@@ -51,7 +51,7 @@ export default {
   },
   computed: {
     dropdownClass() {
-      return this.isDropdownShowing ? 'show' : 'd-none';
+      return this.isDropdownShowing ? 'show' : 'gl-display-none';
     },
   },
   methods: {
@@ -81,7 +81,6 @@ export default {
         })
         .then(() => {
           this.trackStatusUpdate(status);
-
           this.hideDropdown();
         })
         .catch(() => {
@@ -172,12 +171,15 @@ export default {
       <gl-loading-icon v-if="isUpdating" :inline="true" />
       <p
         v-else-if="!isDropdownShowing"
-        class="value m-0"
+        class="value gl-m-0"
         :class="{ 'no-value': !$options.statuses[alert.status] }"
       >
-        <span v-if="$options.statuses[alert.status]" class="gl-text-gray-700">{{
-          $options.statuses[alert.status]
-        }}</span>
+        <span
+          v-if="$options.statuses[alert.status]"
+          class="gl-text-gray-700"
+          data-testid="status"
+          >{{ $options.statuses[alert.status] }}</span
+        >
         <span v-else>
           {{ s__('AlertManagement|None') }}
         </span>
diff --git a/app/assets/javascripts/alert_management/graphql/mutations/alert_set_assignees.graphql b/app/assets/javascripts/alert_management/graphql/mutations/alert_set_assignees.graphql
new file mode 100644
index 00000000000..efeaf8fa372
--- /dev/null
+++ b/app/assets/javascripts/alert_management/graphql/mutations/alert_set_assignees.graphql
@@ -0,0 +1,15 @@
+mutation($projectPath: ID!, $assigneeUsernames: [String!]!, $iid: String!) {
+  alertSetAssignees(
+    input: { iid: $iid, assigneeUsernames: $assigneeUsernames, projectPath: $projectPath }
+  ) {
+    errors
+    alert {
+      iid
+      assignees {
+        nodes {
+          username
+        }
+      }
+    }
+  }
+}
diff --git a/app/assets/javascripts/alert_management/services/index.js b/app/assets/javascripts/alert_management/services/index.js
deleted file mode 100644
index 787603d3e7a..00000000000
--- a/app/assets/javascripts/alert_management/services/index.js
+++ /dev/null
@@ -1,7 +0,0 @@
-import axios from '~/lib/utils/axios_utils';
-
-export default {
-  getAlertManagementList({ endpoint }) {
-    return axios.get(endpoint);
-  },
-};
diff --git a/app/assets/stylesheets/pages/alert_management/details.scss b/app/assets/stylesheets/pages/alert_management/details.scss
index 5a7bde1a3bc..c96127f05d4 100644
--- a/app/assets/stylesheets/pages/alert_management/details.scss
+++ b/app/assets/stylesheets/pages/alert_management/details.scss
@@ -49,4 +49,15 @@
       background-color: $white;
     }
   }
+
+  .assignee-dropdown-item {
+    button {
+      display: flex;
+      align-items: center;
+
+      &::before {
+        top: 50% !important;
+      }
+    }
+  }
 }
diff --git a/app/controllers/clusters/base_controller.rb b/app/controllers/clusters/base_controller.rb
index 8c13cc67be2..6b83400971d 100644
--- a/app/controllers/clusters/base_controller.rb
+++ b/app/controllers/clusters/base_controller.rb
@@ -7,7 +7,7 @@ class Clusters::BaseController < ApplicationController
   before_action :authorize_read_cluster!
 
   before_action do
-    push_frontend_feature_flag(:managed_apps_local_tiller)
+    push_frontend_feature_flag(:managed_apps_local_tiller, clusterable)
   end
 
   helper_method :clusterable
diff --git a/app/graphql/mutations/alert_management/alerts/set_assignees.rb b/app/graphql/mutations/alert_management/alerts/set_assignees.rb
new file mode 100644
index 00000000000..1e0c9fdeeaf
--- /dev/null
+++ b/app/graphql/mutations/alert_management/alerts/set_assignees.rb
@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+module Mutations
+  module AlertManagement
+    module Alerts
+      class SetAssignees < Base
+        graphql_name 'AlertSetAssignees'
+
+        argument :assignee_usernames,
+                 [GraphQL::STRING_TYPE],
+                 required: true,
+                 description: 'The usernames to assign to the alert. Replaces existing assignees by default.'
+
+        argument :operation_mode,
+                 Types::MutationOperationModeEnum,
+                 required: false,
+                 description: 'The operation to perform. Defaults to REPLACE.'
+
+        def resolve(args)
+          alert = authorized_find!(project_path: args[:project_path], iid: args[:iid])
+          result = set_assignees(alert, args[:assignee_usernames], args[:operation_mode])
+
+          prepare_response(result)
+        end
+
+        private
+
+        def set_assignees(alert, assignee_usernames, operation_mode)
+          operation_mode ||= Types::MutationOperationModeEnum.enum[:replace]
+
+          original_assignees = alert.assignees
+          target_users = find_target_users(assignee_usernames)
+
+          assignees = case Types::MutationOperationModeEnum.enum.key(operation_mode).to_sym
+                      when :replace then target_users.uniq
+                      when :append then (original_assignees + target_users).uniq
+                      when :remove then (original_assignees - target_users)
+                      end
+
+          ::AlertManagement::Alerts::UpdateService.new(alert, current_user, assignees: assignees).execute
+        end
+
+        def find_target_users(assignee_usernames)
+          UsersFinder.new(current_user, username: assignee_usernames).execute
+        end
+
+        def prepare_response(result)
+          {
+            alert: result.payload[:alert],
+            errors: result.error? ? [result.message] : []
+          }
+        end
+      end
+    end
+  end
+end
diff --git a/app/graphql/types/mutation_type.rb b/app/graphql/types/mutation_type.rb
index 8d4368cc30a..8874c56dfdb 100644
--- a/app/graphql/types/mutation_type.rb
+++ b/app/graphql/types/mutation_type.rb
@@ -9,6 +9,7 @@ module Types
     mount_mutation Mutations::Admin::SidekiqQueues::DeleteJobs
     mount_mutation Mutations::AlertManagement::CreateAlertIssue
     mount_mutation Mutations::AlertManagement::UpdateAlertStatus
+    mount_mutation Mutations::AlertManagement::Alerts::SetAssignees
     mount_mutation Mutations::AwardEmojis::Add
     mount_mutation Mutations::AwardEmojis::Remove
     mount_mutation Mutations::AwardEmojis::Toggle
diff --git a/app/models/clusters/applications/cert_manager.rb b/app/models/clusters/applications/cert_manager.rb
index 1efa44c39c5..53c90fa56d5 100644
--- a/app/models/clusters/applications/cert_manager.rb
+++ b/app/models/clusters/applications/cert_manager.rb
@@ -38,7 +38,8 @@ module Clusters
           chart: chart,
           files: files.merge(cluster_issuer_file),
           preinstall: pre_install_script,
-          postinstall: post_install_script
+          postinstall: post_install_script,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -47,7 +48,8 @@ module Clusters
           name: 'certmanager',
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,
-          postdelete: post_delete_script
+          postdelete: post_delete_script,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/crossplane.rb b/app/models/clusters/applications/crossplane.rb
index 420e56c1742..2e5a8210b3c 100644
--- a/app/models/clusters/applications/crossplane.rb
+++ b/app/models/clusters/applications/crossplane.rb
@@ -35,7 +35,8 @@ module Clusters
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
-          files: files
+          files: files,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/elastic_stack.rb b/app/models/clusters/applications/elastic_stack.rb
index 0d029aabc3b..679a4d4e447 100644
--- a/app/models/clusters/applications/elastic_stack.rb
+++ b/app/models/clusters/applications/elastic_stack.rb
@@ -34,7 +34,8 @@ module Clusters
           repository: repository,
           files: files,
           preinstall: migrate_to_3_script,
-          postinstall: post_install_script
+          postinstall: post_install_script,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -43,7 +44,8 @@ module Clusters
           name: 'elastic-stack',
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,
-          postdelete: post_delete_script
+          postdelete: post_delete_script,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -118,7 +120,8 @@ module Clusters
           Gitlab::Kubernetes::Helm::DeleteCommand.new(
             name: 'elastic-stack',
             rbac: cluster.platform_kubernetes_rbac?,
-            files: files
+            files: files,
+            local_tiller_enabled: cluster.local_tiller_enabled?
           ).delete_command,
           Gitlab::Kubernetes::KubectlCmd.delete("pvc", "--selector", "release=elastic-stack", "--namespace", Gitlab::Kubernetes::Helm::NAMESPACE)
         ]
diff --git a/app/models/clusters/applications/fluentd.rb b/app/models/clusters/applications/fluentd.rb
index 3fd6e870edc..1bcd39618f6 100644
--- a/app/models/clusters/applications/fluentd.rb
+++ b/app/models/clusters/applications/fluentd.rb
@@ -32,7 +32,8 @@ module Clusters
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
-          files: files
+          files: files,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/helm.rb b/app/models/clusters/applications/helm.rb
index 4a1bcac4bb7..226a9c26db0 100644
--- a/app/models/clusters/applications/helm.rb
+++ b/app/models/clusters/applications/helm.rb
@@ -52,7 +52,8 @@ module Clusters
         Gitlab::Kubernetes::Helm::InitCommand.new(
           name: name,
           files: files,
-          rbac: cluster.platform_kubernetes_rbac?
+          rbac: cluster.platform_kubernetes_rbac?,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -60,7 +61,8 @@ module Clusters
         Gitlab::Kubernetes::Helm::ResetCommand.new(
           name: name,
           files: files,
-          rbac: cluster.platform_kubernetes_rbac?
+          rbac: cluster.platform_kubernetes_rbac?,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/ingress.rb b/app/models/clusters/applications/ingress.rb
index dd354198910..a44450ec7a9 100644
--- a/app/models/clusters/applications/ingress.rb
+++ b/app/models/clusters/applications/ingress.rb
@@ -63,7 +63,8 @@ module Clusters
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
-          files: files
+          files: files,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/jupyter.rb b/app/models/clusters/applications/jupyter.rb
index 056ea355de6..b737f0f962f 100644
--- a/app/models/clusters/applications/jupyter.rb
+++ b/app/models/clusters/applications/jupyter.rb
@@ -45,7 +45,8 @@ module Clusters
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
           files: files,
-          repository: repository
+          repository: repository,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/knative.rb b/app/models/clusters/applications/knative.rb
index 3047da12dd9..b55fc3c45fc 100644
--- a/app/models/clusters/applications/knative.rb
+++ b/app/models/clusters/applications/knative.rb
@@ -77,7 +77,8 @@ module Clusters
           chart: chart,
           files: files,
           repository: REPOSITORY,
-          postinstall: install_knative_metrics
+          postinstall: install_knative_metrics,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -99,7 +100,8 @@ module Clusters
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,
           predelete: delete_knative_services_and_metrics,
-          postdelete: delete_knative_istio_leftovers
+          postdelete: delete_knative_istio_leftovers,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/prometheus.rb b/app/models/clusters/applications/prometheus.rb
index 46ca0d13b65..24bb1df6d22 100644
--- a/app/models/clusters/applications/prometheus.rb
+++ b/app/models/clusters/applications/prometheus.rb
@@ -66,7 +66,8 @@ module Clusters
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
           files: files,
-          postinstall: install_knative_metrics
+          postinstall: install_knative_metrics,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -76,7 +77,8 @@ module Clusters
           version: version,
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
-          files: files_with_replaced_values(values)
+          files: files_with_replaced_values(values),
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -85,7 +87,8 @@ module Clusters
           name: name,
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,
-          predelete: delete_knative_istio_metrics
+          predelete: delete_knative_istio_metrics,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/applications/runner.rb b/app/models/clusters/applications/runner.rb
index 2aa4ca719a5..6d3b6c4ed8f 100644
--- a/app/models/clusters/applications/runner.rb
+++ b/app/models/clusters/applications/runner.rb
@@ -36,7 +36,8 @@ module Clusters
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
           files: files,
-          repository: repository
+          repository: repository,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
diff --git a/app/models/clusters/cluster.rb b/app/models/clusters/cluster.rb
index 81107bb00e3..65dfc108d49 100644
--- a/app/models/clusters/cluster.rb
+++ b/app/models/clusters/cluster.rb
@@ -326,6 +326,10 @@ module Clusters
       end
     end
 
+    def local_tiller_enabled?
+      Feature.enabled?(:managed_apps_local_tiller, clusterable, default_enabled: false)
+    end
+
     private
 
     def unique_management_project_environment_scope
diff --git a/app/models/clusters/concerns/application_core.rb b/app/models/clusters/concerns/application_core.rb
index 297d00aa281..c1f63758906 100644
--- a/app/models/clusters/concerns/application_core.rb
+++ b/app/models/clusters/concerns/application_core.rb
@@ -15,7 +15,7 @@ module Clusters
         def set_initial_status
           return unless not_installable?
 
-          self.status = status_states[:installable] if cluster&.application_helm_available? || ::Gitlab::Kubernetes::Helm.local_tiller_enabled?
+          self.status = status_states[:installable] if cluster&.application_helm_available? || cluster&.local_tiller_enabled?
         end
 
         def can_uninstall?
diff --git a/app/models/clusters/concerns/application_data.rb b/app/models/clusters/concerns/application_data.rb
index 77c606553d2..ade27e69642 100644
--- a/app/models/clusters/concerns/application_data.rb
+++ b/app/models/clusters/concerns/application_data.rb
@@ -7,7 +7,8 @@ module Clusters
         Gitlab::Kubernetes::Helm::DeleteCommand.new(
           name: name,
           rbac: cluster.platform_kubernetes_rbac?,
-          files: files
+          files: files,
+          local_tiller_enabled: cluster.local_tiller_enabled?
         )
       end
 
@@ -32,7 +33,7 @@ module Clusters
       private
 
       def use_tiller_ssl?
-        return false if ::Gitlab::Kubernetes::Helm.local_tiller_enabled?
+        return false if cluster.local_tiller_enabled?
 
         cluster.application_helm.has_ssl?
       end
diff --git a/app/models/clusters/concerns/application_status.rb b/app/models/clusters/concerns/application_status.rb
index 79d1849b05e..86d74ed7b1c 100644
--- a/app/models/clusters/concerns/application_status.rb
+++ b/app/models/clusters/concerns/application_status.rb
@@ -98,7 +98,7 @@ module Clusters
           end
 
           before_transition any => [:installed, :updated] do |application, transition|
-            unless ::Gitlab::Kubernetes::Helm.local_tiller_enabled? || application.is_a?(Clusters::Applications::Helm)
+            unless application.cluster.local_tiller_enabled? || application.is_a?(Clusters::Applications::Helm)
               if transition.event == :make_externally_installed
                 # If an application is externally installed
                 # We assume the helm application is externally installed too
diff --git a/app/services/alert_management/alerts/update_service.rb b/app/services/alert_management/alerts/update_service.rb
new file mode 100644
index 00000000000..76397d2fb48
--- /dev/null
+++ b/app/services/alert_management/alerts/update_service.rb
@@ -0,0 +1,60 @@
+# frozen_string_literal: true
+
+module AlertManagement
+  module Alerts
+    class UpdateService
+      # @param alert [AlertManagement::Alert]
+      # @param current_user [User]
+      # @param params [Hash] Attributes of the alert
+      def initialize(alert, current_user, params)
+        @alert = alert
+        @current_user = current_user
+        @params = params
+      end
+
+      def execute
+        return error_no_permissions unless allowed?
+        return error_no_updates if params.empty?
+
+        filter_assignees
+
+        if alert.update(params)
+          success
+        else
+          error(alert.errors.full_messages.to_sentence)
+        end
+      end
+
+      private
+
+      attr_reader :alert, :current_user, :params
+
+      def allowed?
+        current_user.can?(:update_alert_management_alert, alert)
+      end
+
+      def filter_assignees
+        return if params[:assignees].nil?
+
+        # Take first assignee while multiple are not currently supported
+        params[:assignees] = Array(params[:assignees].first)
+      end
+
+      def success
+        ServiceResponse.success(payload: { alert: alert })
+      end
+
+      def error(message)
+        ServiceResponse.error(payload: { alert: alert }, message: message)
+      end
+
+      def error_no_permissions
+        error(_('You have no permissions'))
+      end
+
+      def error_no_updates
+        error(_('Please provide attributes to update'))
+      end
+    end
+  end
+end
diff --git a/changelogs/unreleased/alert-assignee-dropdown.yml b/changelogs/unreleased/alert-assignee-dropdown.yml
new file mode 100644
index 00000000000..3ad54932780
--- /dev/null
+++ b/changelogs/unreleased/alert-assignee-dropdown.yml
@@ -0,0 +1,5 @@
+---
+title: Allow the assignment of alerts to users from the alert detail view
+merge_request: 33122
+author:
+type: added
diff --git a/doc/api/graphql/reference/gitlab_schema.graphql b/doc/api/graphql/reference/gitlab_schema.graphql
index f7b0855a044..9c478f2d56e 100644
--- a/doc/api/graphql/reference/gitlab_schema.graphql
+++ b/doc/api/graphql/reference/gitlab_schema.graphql
@@ -495,6 +495,61 @@ enum AlertManagementStatus {
   TRIGGERED
 }
 
+"""
+Autogenerated input type of AlertSetAssignees
+"""
+input AlertSetAssigneesInput {
+  """
+  The usernames to assign to the alert. Replaces existing assignees by default.
+  """
+  assigneeUsernames: [String!]!
+
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  The iid of the alert to mutate
+  """
+  iid: String!
+
+  """
+  The operation to perform. Defaults to REPLACE.
+  """
+  operationMode: MutationOperationMode
+
+  """
+  The project the alert to mutate is in
+  """
+  projectPath: ID!
+}
+
+"""
+Autogenerated return type of AlertSetAssignees
+"""
+type AlertSetAssigneesPayload {
+  """
+  The alert after mutation
+  """
+  alert: AlertManagementAlert
+
+  """
+  A unique identifier for the client performing the mutation.
+  """
+  clientMutationId: String
+
+  """
+  Errors encountered during execution of the mutation.
+  """
+  errors: [String!]!
+
+  """
+  The issue created after mutation
+  """
+  issue: Issue
+}
+
 """
 An emoji awarded by a user.
 """
@@ -7451,6 +7506,7 @@ type Mutation {
   addAwardEmoji(input: AddAwardEmojiInput!): AddAwardEmojiPayload
   addProjectToSecurityDashboard(input: AddProjectToSecurityDashboardInput!): AddProjectToSecurityDashboardPayload
   adminSidekiqQueuesDeleteJobs(input: AdminSidekiqQueuesDeleteJobsInput!): AdminSidekiqQueuesDeleteJobsPayload
+  alertSetAssignees(input: AlertSetAssigneesInput!): AlertSetAssigneesPayload
   boardListUpdateLimitMetrics(input: BoardListUpdateLimitMetricsInput!): BoardListUpdateLimitMetricsPayload
   commitCreate(input: CommitCreateInput!): CommitCreatePayload
   createAlertIssue(input: CreateAlertIssueInput!): CreateAlertIssuePayload
diff --git a/doc/api/graphql/reference/gitlab_schema.json b/doc/api/graphql/reference/gitlab_schema.json
index e4654b97b6e..90aaeac3c27 100644
--- a/doc/api/graphql/reference/gitlab_schema.json
+++ b/doc/api/graphql/reference/gitlab_schema.json
@@ -1175,6 +1175,168 @@
           ],
           "possibleTypes": null
         },
+        {
+          "kind": "INPUT_OBJECT",
+          "name": "AlertSetAssigneesInput",
+          "description": "Autogenerated input type of AlertSetAssignees",
+          "fields": null,
+          "inputFields": [
+            {
+              "name": "projectPath",
+              "description": "The project the alert to mutate is in",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "ID",
+                  "ofType": null
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "iid",
+              "description": "The iid of the alert to mutate",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "SCALAR",
+                  "name": "String",
+                  "ofType": null
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "assigneeUsernames",
+              "description": "The usernames to assign to the alert. Replaces existing assignees by default.",
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "LIST",
+                  "name": null,
+                  "ofType": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "SCALAR",
+                      "name": "String",
+                      "ofType": null
+                    }
+                  }
+                }
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "operationMode",
+              "description": "The operation to perform. Defaults to REPLACE.",
+              "type": {
+                "kind": "ENUM",
+                "name": "MutationOperationMode",
+                "ofType": null
+              },
+              "defaultValue": null
+            },
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "defaultValue": null
+            }
+          ],
+          "interfaces": null,
+          "enumValues": null,
+          "possibleTypes": null
+        },
+        {
+          "kind": "OBJECT",
+          "name": "AlertSetAssigneesPayload",
+          "description": "Autogenerated return type of AlertSetAssignees",
+          "fields": [
+            {
+              "name": "alert",
+              "description": "The alert after mutation",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "AlertManagementAlert",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "clientMutationId",
+              "description": "A unique identifier for the client performing the mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "SCALAR",
+                "name": "String",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "errors",
+              "description": "Errors encountered during execution of the mutation.",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "NON_NULL",
+                "name": null,
+                "ofType": {
+                  "kind": "LIST",
+                  "name": null,
+                  "ofType": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "SCALAR",
+                      "name": "String",
+                      "ofType": null
+                    }
+                  }
+                }
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
+            {
+              "name": "issue",
+              "description": "The issue created after mutation",
+              "args": [
+
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "Issue",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            }
+          ],
+          "inputFields": null,
+          "interfaces": [
+
+          ],
+          "enumValues": null,
+          "possibleTypes": null
+        },
         {
           "kind": "OBJECT",
           "name": "AwardEmoji",
@@ -20963,6 +21125,33 @@
               "isDeprecated": false,
               "deprecationReason": null
             },
+            {
+              "name": "alertSetAssignees",
+              "description": null,
+              "args": [
+                {
+                  "name": "input",
+                  "description": null,
+                  "type": {
+                    "kind": "NON_NULL",
+                    "name": null,
+                    "ofType": {
+                      "kind": "INPUT_OBJECT",
+                      "name": "AlertSetAssigneesInput",
+                      "ofType": null
+                    }
+                  },
+                  "defaultValue": null
+                }
+              ],
+              "type": {
+                "kind": "OBJECT",
+                "name": "AlertSetAssigneesPayload",
+                "ofType": null
+              },
+              "isDeprecated": false,
+              "deprecationReason": null
+            },
             {
               "name": "boardListUpdateLimitMetrics",
               "description": null,
diff --git a/doc/api/graphql/reference/index.md b/doc/api/graphql/reference/index.md
index 34f7a4c621e..7387dfaaa55 100644
--- a/doc/api/graphql/reference/index.md
+++ b/doc/api/graphql/reference/index.md
@@ -90,6 +90,17 @@ Represents total number of alerts for the represented categories
 | `resolved` | Int | Number of alerts with status RESOLVED for the project |
 | `triggered` | Int | Number of alerts with status TRIGGERED for the project |
 
+## AlertSetAssigneesPayload
+
+Autogenerated return type of AlertSetAssignees
+
+| Name  | Type  | Description |
+| ---   |  ---- | ----------  |
+| `alert` | AlertManagementAlert | The alert after mutation |
+| `clientMutationId` | String | A unique identifier for the client performing the mutation. |
+| `errors` | String! => Array | Errors encountered during execution of the mutation. |
+| `issue` | Issue | The issue created after mutation |
+
 ## AwardEmoji
 
 An emoji awarded by a user.
diff --git a/doc/ci/merge_request_pipelines/pipelines_for_merged_results/index.md b/doc/ci/merge_request_pipelines/pipelines_for_merged_results/index.md
index ac79c2152c0..a43085c8e7a 100644
--- a/doc/ci/merge_request_pipelines/pipelines_for_merged_results/index.md
+++ b/doc/ci/merge_request_pipelines/pipelines_for_merged_results/index.md
@@ -59,7 +59,7 @@ To enable pipelines for merged results for your project:
 1. [Configure your CI/CD configuration file](../index.md#configuring-pipelines-for-merge-requests)
    so that the pipeline or individual jobs run for merge requests.
 1. Visit your project's **Settings > General** and expand **Merge requests**.
-1. Check **Merge pipelines will try to validate the post-merge result prior to merging**.
+1. Check **Enable merge trains and pipelines for merged results**.
 1. Click **Save changes**.
 
 CAUTION: **Caution:**
diff --git a/doc/ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/index.md b/doc/ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/index.md
index c4d16d73243..fc8e6368d72 100644
--- a/doc/ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/index.md
+++ b/doc/ci/merge_request_pipelines/pipelines_for_merged_results/merge_trains/index.md
@@ -82,7 +82,7 @@ To enable merge trains for your project:
 1. [Configure your CI/CD configuration file](../../index.md#configuring-pipelines-for-merge-requests)
    so that the pipeline or individual jobs run for merge requests.
 1. Visit your project's **Settings > General** and expand **Merge requests**.
-1. Check **Merge pipelines will try to validate the post-merge result prior to merging**.
+1. Check **Enable merge trains and pipelines for merged results**.
 1. Click **Save changes**.
 
 CAUTION: **Caution:**
@@ -187,7 +187,7 @@ run a new successful pipeline before you can re-add a merge request to a merge t
 
 Merge trains ensure that each pipeline has succeeded before a merge happens, so
 you can clear the **Pipelines must succeed** check box and keep
-**Merge pipelines will try to validate the post-merge result prior to merging** (merge trains) enabled.
+**Enable merge trains and pipelines for merged results** (merge trains) enabled.
 
 If you want to keep the **Pipelines must succeed** option enabled along with Merge
 Trains, you can create a new pipeline for merged results when this error occurs by
diff --git a/doc/user/instance/clusters/index.md b/doc/user/instance/clusters/index.md
index 4a8b45f6643..8059b8ca642 100644
--- a/doc/user/instance/clusters/index.md
+++ b/doc/user/instance/clusters/index.md
@@ -12,8 +12,7 @@ projects.
 
 ## Cluster precedence
 
-GitLab will try [to match](../../../ci/environments/index.md#scoping-environments-with-specs) clusters in
-the following order:
+GitLab will try to match clusters in the following order:
 
 - Project-level clusters.
 - Group-level clusters.
diff --git a/doc/user/project/clusters/add_eks_clusters.md b/doc/user/project/clusters/add_eks_clusters.md
index 34dde49deae..4d9604bf467 100644
--- a/doc/user/project/clusters/add_eks_clusters.md
+++ b/doc/user/project/clusters/add_eks_clusters.md
@@ -148,7 +148,7 @@ To create and add a new Kubernetes cluster to your project, group, or instance:
    - **VPC** - Select a [VPC](https://docs.aws.amazon.com/vpc/latest/userguide/what-is-amazon-vpc.html)
      to use for your EKS Cluster resources.
    - **Subnets** - Choose the [subnets](https://docs.aws.amazon.com/vpc/latest/userguide/VPC_Subnets.html)
-     in your VPC where your worker nodes will run.
+     in your VPC where your worker nodes will run. You must select at least two.
    - **Security group** - Choose the [security group](https://docs.aws.amazon.com/vpc/latest/userguide/VPC_SecurityGroups.html)
      to apply to the EKS-managed Elastic Network Interfaces that are created in your worker node subnets.
    - **Instance type** - The [instance type](https://aws.amazon.com/ec2/instance-types/) of your worker nodes.
diff --git a/doc/user/project/clusters/add_gke_clusters.md b/doc/user/project/clusters/add_gke_clusters.md
index e056b4d942f..2746076befe 100644
--- a/doc/user/project/clusters/add_gke_clusters.md
+++ b/doc/user/project/clusters/add_gke_clusters.md
@@ -24,8 +24,6 @@ requirements are met:
 Starting from [GitLab 12.4](https://gitlab.com/gitlab-org/gitlab/-/issues/25925), all the GKE clusters
 provisioned by GitLab are [VPC-native](https://cloud.google.com/kubernetes-engine/docs/how-to/alias-ips).
 
-### Important notes
-
 Note the following:
 
 - The [Google authentication integration](../../../integration/google.md) must be enabled in GitLab
@@ -38,9 +36,10 @@ Note the following:
   cluster's pod address IP range will be set to /16 instead of the regular /14. /16 is a CIDR
   notation.
 - GitLab requires basic authentication enabled and a client certificate issued for the cluster to
-  set up an [initial service account](add_remove_clusters.md#access-controls). Starting from [GitLab
-  11.10](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/58208), the cluster creation process will
-  explicitly request that basic authentication and client certificate is enabled.
+  set up an [initial service account](add_remove_clusters.md#access-controls). In [GitLab versions
+  11.10 and later](https://gitlab.com/gitlab-org/gitlab-foss/-/issues/58208), the cluster creation process
+  explicitly requests GKE to create clusters with basic authentication enabled and a client
+  certificate.
 
 ### Creating the cluster on GKE
 
diff --git a/lib/gitlab/kubernetes/helm.rb b/lib/gitlab/kubernetes/helm.rb
index 00ab7109267..9507f7bc117 100644
--- a/lib/gitlab/kubernetes/helm.rb
+++ b/lib/gitlab/kubernetes/helm.rb
@@ -10,12 +10,6 @@ module Gitlab
       SERVICE_ACCOUNT = 'tiller'
       CLUSTER_ROLE_BINDING = 'tiller-admin'
       CLUSTER_ROLE = 'cluster-admin'
-
-      MANAGED_APPS_LOCAL_TILLER_FEATURE_FLAG = :managed_apps_local_tiller
-
-      def self.local_tiller_enabled?
-        Feature.enabled?(MANAGED_APPS_LOCAL_TILLER_FEATURE_FLAG)
-      end
     end
   end
 end
diff --git a/lib/gitlab/kubernetes/helm/base_command.rb b/lib/gitlab/kubernetes/helm/base_command.rb
index 31cd21f17e0..f27ad05599e 100644
--- a/lib/gitlab/kubernetes/helm/base_command.rb
+++ b/lib/gitlab/kubernetes/helm/base_command.rb
@@ -3,7 +3,24 @@
 module Gitlab
   module Kubernetes
     module Helm
-      module BaseCommand
+      class BaseCommand
+        attr_reader :name, :files
+
+        def initialize(rbac:, name:, files:, local_tiller_enabled:)
+          @rbac = rbac
+          @name = name
+          @files = files
+          @local_tiller_enabled = local_tiller_enabled
+        end
+
+        def rbac?
+          @rbac
+        end
+
+        def local_tiller_enabled?
+          @local_tiller_enabled
+        end
+
         def pod_resource
           pod_service_account_name = rbac? ? service_account_name : nil
 
@@ -46,18 +63,6 @@ module Gitlab
           files.keys
         end
 
-        def name
-          raise "Not implemented"
-        end
-
-        def rbac?
-          raise "Not implemented"
-        end
-
-        def files
-          raise "Not implemented"
-        end
-
         private
 
         def files_dir
diff --git a/lib/gitlab/kubernetes/helm/client_command.rb b/lib/gitlab/kubernetes/helm/client_command.rb
index e7ade7e4d39..24458e1b4b3 100644
--- a/lib/gitlab/kubernetes/helm/client_command.rb
+++ b/lib/gitlab/kubernetes/helm/client_command.rb
@@ -57,10 +57,6 @@ module Gitlab
             '--tls-key', "#{files_dir}/key.pem"
           ]
         end
-
-        def local_tiller_enabled?
-          ::Gitlab::Kubernetes::Helm.local_tiller_enabled?
-        end
       end
     end
   end
diff --git a/lib/gitlab/kubernetes/helm/delete_command.rb b/lib/gitlab/kubernetes/helm/delete_command.rb
index 771444ee9ee..3bb41d09994 100644
--- a/lib/gitlab/kubernetes/helm/delete_command.rb
+++ b/lib/gitlab/kubernetes/helm/delete_command.rb
@@ -3,17 +3,13 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class DeleteCommand
-        include BaseCommand
+      class DeleteCommand < BaseCommand
         include ClientCommand
 
         attr_reader :predelete, :postdelete
-        attr_accessor :name, :files
 
-        def initialize(name:, rbac:, files:, predelete: nil, postdelete: nil)
-          @name = name
-          @files = files
-          @rbac = rbac
+        def initialize(predelete: nil, postdelete: nil, **args)
+          super(**args)
           @predelete = predelete
           @postdelete = postdelete
         end
@@ -32,10 +28,6 @@ module Gitlab
           "uninstall-#{name}"
         end
 
-        def rbac?
-          @rbac
-        end
-
         def delete_command
           command = ['helm', 'delete', '--purge', name] + tls_flags_if_remote_tiller
 
diff --git a/lib/gitlab/kubernetes/helm/init_command.rb b/lib/gitlab/kubernetes/helm/init_command.rb
index 058f38f2c9c..e4844e255c5 100644
--- a/lib/gitlab/kubernetes/helm/init_command.rb
+++ b/lib/gitlab/kubernetes/helm/init_command.rb
@@ -3,27 +3,13 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class InitCommand
-        include BaseCommand
-
-        attr_reader :name, :files
-
-        def initialize(name:, files:, rbac:)
-          @name = name
-          @files = files
-          @rbac = rbac
-        end
-
+      class InitCommand < BaseCommand
         def generate_script
           super + [
             init_helm_command
           ].join("\n")
         end
 
-        def rbac?
-          @rbac
-        end
-
         private
 
         def init_helm_command
diff --git a/lib/gitlab/kubernetes/helm/install_command.rb b/lib/gitlab/kubernetes/helm/install_command.rb
index 3784aecccb5..cf6d993cad4 100644
--- a/lib/gitlab/kubernetes/helm/install_command.rb
+++ b/lib/gitlab/kubernetes/helm/install_command.rb
@@ -3,19 +3,16 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class InstallCommand
-        include BaseCommand
+      class InstallCommand < BaseCommand
         include ClientCommand
 
-        attr_reader :name, :files, :chart, :repository, :preinstall, :postinstall
+        attr_reader :chart, :repository, :preinstall, :postinstall
         attr_accessor :version
 
-        def initialize(name:, chart:, files:, rbac:, version: nil, repository: nil, preinstall: nil, postinstall: nil)
-          @name = name
+        def initialize(chart:, version: nil, repository: nil, preinstall: nil, postinstall: nil, **args)
+          super(**args)
           @chart = chart
           @version = version
-          @rbac = rbac
-          @files = files
           @repository = repository
           @preinstall = preinstall
           @postinstall = postinstall
@@ -33,10 +30,6 @@ module Gitlab
           ].compact.join("\n")
         end
 
-        def rbac?
-          @rbac
-        end
-
         private
 
         # Uses `helm upgrade --install` which means we can use this for both
diff --git a/lib/gitlab/kubernetes/helm/patch_command.rb b/lib/gitlab/kubernetes/helm/patch_command.rb
index ed7a5c2b2d6..1a5fab116bd 100644
--- a/lib/gitlab/kubernetes/helm/patch_command.rb
+++ b/lib/gitlab/kubernetes/helm/patch_command.rb
@@ -5,23 +5,21 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class PatchCommand
-        include BaseCommand
+      class PatchCommand < BaseCommand
         include ClientCommand
 
-        attr_reader :name, :files, :chart, :repository
+        attr_reader :chart, :repository
         attr_accessor :version
 
-        def initialize(name:, chart:, files:, rbac:, version:, repository: nil)
+        def initialize(chart:, version:, repository: nil, **args)
+          super(**args)
+
           # version is mandatory to prevent chart mismatches
           # we do not want our values interpreted in the context of the wrong version
           raise ArgumentError, 'version is required' if version.blank?
 
-          @name = name
           @chart = chart
           @version = version
-          @rbac = rbac
-          @files = files
           @repository = repository
         end
 
@@ -35,10 +33,6 @@ module Gitlab
           ].compact.join("\n")
         end
 
-        def rbac?
-          @rbac
-        end
-
         private
 
         def upgrade_command
diff --git a/lib/gitlab/kubernetes/helm/reset_command.rb b/lib/gitlab/kubernetes/helm/reset_command.rb
index 13176360227..f1f7938039c 100644
--- a/lib/gitlab/kubernetes/helm/reset_command.rb
+++ b/lib/gitlab/kubernetes/helm/reset_command.rb
@@ -3,18 +3,9 @@
 module Gitlab
   module Kubernetes
     module Helm
-      class ResetCommand
-        include BaseCommand
+      class ResetCommand < BaseCommand
         include ClientCommand
 
-        attr_reader :name, :files
-
-        def initialize(name:, rbac:, files:)
-          @name = name
-          @files = files
-          @rbac = rbac
-        end
-
         def generate_script
           super + [
             reset_helm_command,
@@ -23,10 +14,6 @@ module Gitlab
           ].join("\n")
         end
 
-        def rbac?
-          @rbac
-        end
-
         def pod_name
           "uninstall-#{name}"
         end
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 88e707836ce..afeecab9644 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -1846,6 +1846,9 @@ msgstr ""
 msgid "AlertManagement|Alert"
 msgstr ""
 
+msgid "AlertManagement|Alert assignee(s): %{assignees}"
+msgstr ""
+
 msgid "AlertManagement|Alert detail"
 msgstr ""
 
@@ -1861,9 +1864,18 @@ msgstr ""
 msgid "AlertManagement|All alerts"
 msgstr ""
 
+msgid "AlertManagement|Assign Assignees"
+msgstr ""
+
 msgid "AlertManagement|Assign status"
 msgstr ""
 
+msgid "AlertManagement|Assignee"
+msgstr ""
+
+msgid "AlertManagement|Assignee(s)"
+msgstr ""
+
 msgid "AlertManagement|Assignees"
 msgstr ""
 
@@ -1903,6 +1915,9 @@ msgstr ""
 msgid "AlertManagement|More information"
 msgstr ""
 
+msgid "AlertManagement|No Matching Results"
+msgstr ""
+
 msgid "AlertManagement|No alert data to display."
 msgstr ""
 
@@ -1951,6 +1966,12 @@ msgstr ""
 msgid "AlertManagement|There was an error displaying the alerts. Confirm your endpoint's configuration details to ensure alerts appear."
 msgstr ""
 
+msgid "AlertManagement|There was an error while updating the assignee(s) list. Please try again."
+msgstr ""
+
+msgid "AlertManagement|There was an error while updating the assignee(s) of the alert. Please try again."
+msgstr ""
+
 msgid "AlertManagement|There was an error while updating the status of the alert. Please try again."
 msgstr ""
 
@@ -16318,6 +16339,9 @@ msgstr ""
 msgid "Please provide a valid email address."
 msgstr ""
 
+msgid "Please provide attributes to update"
+msgstr ""
+
 msgid "Please refer to <a href=\"%{docs_url}\">%{docs_url}</a>"
 msgstr ""
 
@@ -17221,6 +17245,9 @@ msgstr ""
 msgid "ProjectSettings|Enable 'Delete source branch' option by default"
 msgstr ""
 
+msgid "ProjectSettings|Enable merge trains and pipelines for merged results"
+msgstr ""
+
 msgid "ProjectSettings|Every merge creates a merge commit"
 msgstr ""
 
@@ -17287,9 +17314,6 @@ msgstr ""
 msgid "ProjectSettings|Merge options"
 msgstr ""
 
-msgid "ProjectSettings|Merge pipelines will try to validate the post-merge result prior to merging"
-msgstr ""
-
 msgid "ProjectSettings|Merge requests"
 msgstr ""
 
@@ -17317,6 +17341,9 @@ msgstr ""
 msgid "ProjectSettings|Pipelines"
 msgstr ""
 
+msgid "ProjectSettings|Pipelines for merge requests must be enabled in the CI/CD configuration file, or pipelines could be unresolvable or dropped"
+msgstr ""
+
 msgid "ProjectSettings|Pipelines must succeed"
 msgstr ""
 
diff --git a/qa/qa/resource/ssh_key.rb b/qa/qa/resource/ssh_key.rb
index b948bf3969b..317d70ef2c3 100644
--- a/qa/qa/resource/ssh_key.rb
+++ b/qa/qa/resource/ssh_key.rb
@@ -6,6 +6,7 @@ module QA
       extend Forwardable
 
       attr_reader :title
+      attr_accessor :expires_at
 
       attribute :id
 
@@ -53,13 +54,27 @@ module QA
       def api_post_body
         {
           title: title,
-          key: public_key
+          key: public_key,
+          expires_at: expires_at
         }
       end
 
       def api_delete_path
         "/user/keys/#{id}"
       end
+
+      def replicated?
+        api_client = Runtime::API::Client.new(:geo_secondary)
+
+        QA::Runtime::Logger.debug('Checking for SSH key replication')
+
+        Support::Retrier.retry_until(max_duration: QA::EE::Runtime::Geo.max_db_replication_time, sleep_interval: 3) do
+          response = get Runtime::API::Request.new(api_client, api_get_path).url
+
+          response.code == QA::Support::Api::HTTP_STATUS_OK &&
+            parse_body(response)[:title].include?(title)
+        end
+      end
     end
   end
 end
diff --git a/qa/qa/specs/features/browser_ui/8_monitor/all_monitor_core_features_spec.rb b/qa/qa/specs/features/browser_ui/8_monitor/all_monitor_core_features_spec.rb
index 45273655bb6..a9ed6651069 100644
--- a/qa/qa/specs/features/browser_ui/8_monitor/all_monitor_core_features_spec.rb
+++ b/qa/qa/specs/features/browser_ui/8_monitor/all_monitor_core_features_spec.rb
@@ -1,11 +1,16 @@
 # frozen_string_literal: true
 
 module QA
-  context 'Monitor', quarantine: { issue: 'https://gitlab.com/gitlab-org/gitlab/-/issues/217705', type: :flaky } do
-    describe 'with Prometheus Gitlab-managed cluster', :orchestrated, :kubernetes, :docker, :runner do
+  context 'Monitor' do
+    describe 'with Prometheus in a Gitlab-managed cluster', :orchestrated, :kubernetes do
       before :all do
-        Flow::Login.sign_in
-        @project, @runner = deploy_project_with_prometheus
+        @cluster = Service::KubernetesCluster.new.create!
+        @project = Resource::Project.fabricate_via_api! do |project|
+          project.name = 'monitoring-project'
+          project.auto_devops_enabled = true
+        end
+
+        deploy_project_with_prometheus
       end
 
       before do
@@ -14,7 +19,6 @@ module QA
       end
 
       after :all do
-        @runner.remove_via_api!
         @cluster.remove!
       end
 
@@ -27,81 +31,94 @@ module QA
       it 'duplicates to create dashboard to custom' do
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          dashboard.duplicate_dashboard
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          on_dashboard.duplicate_dashboard
 
-          expect(dashboard).to have_metrics
-          expect(dashboard).to have_edit_dashboard_enabled
+          expect(on_dashboard).to have_metrics
+          expect(on_dashboard).to have_edit_dashboard_enabled
         end
       end
 
       it 'verifies data on filtered deployed environment' do
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          dashboard.filter_environment
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          on_dashboard.filter_environment
 
-          expect(dashboard).to have_metrics
+          expect(on_dashboard).to have_metrics
         end
       end
 
       it 'filters using the quick range' do
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          dashboard.show_last('30 minutes')
-          expect(dashboard).to have_metrics
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          on_dashboard.show_last('30 minutes')
+          expect(on_dashboard).to have_metrics
 
-          dashboard.show_last('3 hours')
-          expect(dashboard).to have_metrics
+          on_dashboard.show_last('3 hours')
+          expect(on_dashboard).to have_metrics
 
-          dashboard.show_last('1 day')
-          expect(dashboard).to have_metrics
+          on_dashboard.show_last('1 day')
+          expect(on_dashboard).to have_metrics
         end
       end
 
       private
 
       def deploy_project_with_prometheus
-        project = Resource::Project.fabricate_via_api! do |project|
-          project.name = 'cluster-with-prometheus'
-          project.description = 'Cluster with Prometheus'
+        %w[
+          CODE_QUALITY_DISABLED TEST_DISABLED LICENSE_MANAGEMENT_DISABLED
+          SAST_DISABLED DAST_DISABLED DEPENDENCY_SCANNING_DISABLED
+          CONTAINER_SCANNING_DISABLED PERFORMANCE_DISABLED
+        ].each do |key|
+          Resource::CiVariable.fabricate_via_api! do |resource|
+            resource.project = @project
+            resource.key = key
+            resource.value = '1'
+            resource.masked = false
+          end
         end
 
-        runner = Resource::Runner.fabricate_via_api! do |runner|
-          runner.project = project
-          runner.name = project.name
-        end
+        Flow::Login.sign_in
 
-        @cluster = Service::KubernetesCluster.new.create!
-
-        cluster_props = Resource::KubernetesCluster::ProjectCluster.fabricate! do |cluster_settings|
-          cluster_settings.project = project
+        Resource::KubernetesCluster::ProjectCluster.fabricate! do |cluster_settings|
+          cluster_settings.project = @project
           cluster_settings.cluster = @cluster
           cluster_settings.install_helm_tiller = true
+          cluster_settings.install_runner = true
           cluster_settings.install_ingress = true
           cluster_settings.install_prometheus = true
         end
 
-        Resource::CiVariable.fabricate_via_api! do |ci_variable|
-          ci_variable.project = project
-          ci_variable.key = 'AUTO_DEVOPS_DOMAIN'
-          ci_variable.value = cluster_props.ingress_ip
-          ci_variable.masked = false
-        end
-
         Resource::Repository::ProjectPush.fabricate! do |push|
-          push.project = project
+          push.project = @project
           push.directory = Pathname
                                .new(__dir__)
-                               .join('../../../../fixtures/monitored_auto_devops')
+                               .join('../../../../fixtures/auto_devops_rack')
           push.commit_message = 'Create AutoDevOps compatible Project for Monitoring'
         end
 
         Page::Project::Menu.perform(&:click_ci_cd_pipelines)
-        Page::Project::Pipeline::Index.perform(&:wait_for_latest_pipeline_success_or_retry)
+        Page::Project::Pipeline::Index.perform(&:click_on_latest_pipeline)
 
-        [project, runner]
+        Page::Project::Pipeline::Show.perform do |pipeline|
+          pipeline.click_job('build')
+        end
+        Page::Project::Job::Show.perform do |job|
+          expect(job).to be_successful(timeout: 600)
+
+          job.click_element(:pipeline_path)
+        end
+
+        Page::Project::Pipeline::Show.perform do |pipeline|
+          pipeline.click_job('production')
+        end
+        Page::Project::Job::Show.perform do |job|
+          expect(job).to be_successful(timeout: 1200)
+
+          job.click_element(:pipeline_path)
+        end
       end
 
       def verify_add_custom_metric
@@ -115,8 +132,8 @@ module QA
 
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          expect(dashboard).to have_custom_metric('HTTP Requests Total')
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          expect(on_dashboard).to have_custom_metric('HTTP Requests Total')
         end
       end
 
@@ -130,8 +147,8 @@ module QA
 
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          expect(dashboard).to have_custom_metric('Throughput')
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          expect(on_dashboard).to have_custom_metric('Throughput')
         end
       end
 
@@ -146,8 +163,8 @@ module QA
 
         Page::Project::Menu.perform(&:go_to_operations_metrics)
 
-        Page::Project::Operations::Metrics::Show.perform do |dashboard|
-          expect(dashboard).not_to have_custom_metric('Throughput')
+        Page::Project::Operations::Metrics::Show.perform do |on_dashboard|
+          expect(on_dashboard).not_to have_custom_metric('Throughput')
         end
       end
     end
diff --git a/spec/frontend/alert_management/components/alert_management_detail_spec.js b/spec/frontend/alert_management/components/alert_management_detail_spec.js
index bbf6c5428be..14e45a4f563 100644
--- a/spec/frontend/alert_management/components/alert_management_detail_spec.js
+++ b/spec/frontend/alert_management/components/alert_management_detail_spec.js
@@ -1,5 +1,7 @@
 import { mount, shallowMount } from '@vue/test-utils';
 import { GlAlert, GlLoadingIcon, GlTable } from '@gitlab/ui';
+import axios from 'axios';
+import MockAdapter from 'axios-mock-adapter';
 import AlertDetails from '~/alert_management/components/alert_details.vue';
 import createIssueQuery from '~/alert_management/graphql/mutations/create_issue_from_alert.graphql';
 import { joinPaths } from '~/lib/utils/url_utility';
@@ -14,6 +16,7 @@ const mockAlert = mockAlerts[0];
 
 describe('AlertDetails', () => {
   let wrapper;
+  let mock;
   const projectPath = 'root/alerts';
   const projectIssuesPath = 'root/alerts/-/issues';
 
@@ -43,12 +46,17 @@ describe('AlertDetails', () => {
     });
   }
 
+  beforeEach(() => {
+    mock = new MockAdapter(axios);
+  });
+
   afterEach(() => {
     if (wrapper) {
       if (wrapper) {
         wrapper.destroy();
       }
     }
+    mock.restore();
   });
 
   const findCreateIssueBtn = () => wrapper.find('[data-testid="createIssueBtn"]');
diff --git a/spec/frontend/alert_management/components/alert_managment_sidebar_assignees_spec.js b/spec/frontend/alert_management/components/alert_managment_sidebar_assignees_spec.js
new file mode 100644
index 00000000000..c1b9746c308
--- /dev/null
+++ b/spec/frontend/alert_management/components/alert_managment_sidebar_assignees_spec.js
@@ -0,0 +1,133 @@
+import { shallowMount } from '@vue/test-utils';
+import axios from 'axios';
+import MockAdapter from 'axios-mock-adapter';
+import { GlDropdownItem } from '@gitlab/ui';
+import SidebarAssignee from '~/alert_management/components/sidebar/sidebar_assignee.vue';
+import SidebarAssignees from '~/alert_management/components/sidebar/sidebar_assignees.vue';
+import AlertSetAssignees from '~/alert_management/graphql/mutations/alert_set_assignees.graphql';
+import mockAlerts from '../mocks/alerts.json';
+
+const mockAlert = mockAlerts[0];
+
+describe('Alert Details Sidebar Assignees', () => {
+  let wrapper;
+  let mock;
+
+  function mountComponent({
+    data,
+    users = [],
+    isDropdownSearching = false,
+    sidebarCollapsed = true,
+    loading = false,
+    stubs = {},
+  } = {}) {
+    wrapper = shallowMount(SidebarAssignees, {
+      data() {
+        return {
+          users,
+          isDropdownSearching,
+        };
+      },
+      propsData: {
+        alert: { ...mockAlert },
+        ...data,
+        sidebarCollapsed,
+        projectPath: 'projectPath',
+      },
+      mocks: {
+        $apollo: {
+          mutate: jest.fn(),
+          queries: {
+            alert: {
+              loading,
+            },
+          },
+        },
+      },
+      stubs,
+    });
+  }
+
+  afterEach(() => {
+    if (wrapper) {
+      wrapper.destroy();
+    }
+    mock.restore();
+  });
+
+  describe('updating the alert status', () => {
+    const mockUpdatedMutationResult = {
+      data: {
+        updateAlertStatus: {
+          errors: [],
+          alert: {
+            assigneeUsernames: ['root'],
+          },
+        },
+      },
+    };
+
+    beforeEach(() => {
+      mock = new MockAdapter(axios);
+      const path = '/autocomplete/users.json';
+      const users = [
+        {
+          avatar_url:
+            'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80&d=identicon',
+          id: 1,
+          name: 'User 1',
+          username: 'root',
+        },
+        {
+          avatar_url:
+            'https://www.gravatar.com/avatar/e64c7d89f26bd1972efa854d13d7dd61?s=80&d=identicon',
+          id: 2,
+          name: 'User 2',
+          username: 'not-root',
+        },
+      ];
+
+      mock.onGet(path).replyOnce(200, users);
+      mountComponent({
+        data: { alert: mockAlert },
+        sidebarCollapsed: false,
+        loading: false,
+        users,
+        stubs: {
+          SidebarAssignee,
+        },
+      });
+    });
+
+    it('renders a unassigned option', () => {
+      wrapper.setData({ isDropdownSearching: false });
+      return wrapper.vm.$nextTick().then(() => {
+        expect(wrapper.find(GlDropdownItem).text()).toBe('Unassigned');
+      });
+    });
+
+    it('calls `$apollo.mutate` with `AlertSetAssignees` mutation and variables containing `iid`, `assigneeUsernames`, & `projectPath`', () => {
+      jest.spyOn(wrapper.vm.$apollo, 'mutate').mockResolvedValue(mockUpdatedMutationResult);
+      wrapper.setData({ isDropdownSearching: false });
+
+      return wrapper.vm.$nextTick().then(() => {
+        wrapper.find(SidebarAssignee).vm.$emit('update-alert-assignees', 'root');
+
+        expect(wrapper.vm.$apollo.mutate).toHaveBeenCalledWith({
+          mutation: AlertSetAssignees,
+          variables: {
+            iid: '1527542',
+            assigneeUsernames: ['root'],
+            projectPath: 'projectPath',
+          },
+        });
+      });
+    });
+
+    it('stops updating and cancels loading when the request fails', () => {
+      jest.spyOn(wrapper.vm.$apollo, 'mutate').mockReturnValue(Promise.reject(new Error()));
+      wrapper.vm.updateAlertAssignees('root');
+      expect(wrapper.find('[data-testid="assigned-users"]').text()).toBe('Unassigned');
+    });
+  });
+});
diff --git a/spec/frontend/alert_management/components/alert_sidebar_spec.js b/spec/frontend/alert_management/components/alert_sidebar_spec.js
index 1d581e8e2f1..5fa6048de1b 100644
--- a/spec/frontend/alert_management/components/alert_sidebar_spec.js
+++ b/spec/frontend/alert_management/components/alert_sidebar_spec.js
@@ -1,20 +1,32 @@
-import { shallowMount } from '@vue/test-utils';
+import { shallowMount, mount } from '@vue/test-utils';
+import axios from 'axios';
+import MockAdapter from 'axios-mock-adapter';
 import AlertSidebar from '~/alert_management/components/alert_sidebar.vue';
+import SidebarAssignees from '~/alert_management/components/sidebar/sidebar_assignees.vue';
+import mockAlerts from '../mocks/alerts.json';
+
+const mockAlert = mockAlerts[0];
 
 describe('Alert Details Sidebar', () => {
   let wrapper;
+  let mock;
 
   function mountComponent({
     sidebarCollapsed = true,
     mountMethod = shallowMount,
+    alertAssignee = false,
     stubs = {},
+    alert = {},
   } = {}) {
     wrapper = mountMethod(AlertSidebar, {
       propsData: {
-        alert: {},
+        alert,
         sidebarCollapsed,
         projectPath: 'projectPath',
       },
+      provide: {
+        glFeatures: { alertAssignee },
+      },
       stubs,
     });
   }
@@ -23,15 +35,30 @@ describe('Alert Details Sidebar', () => {
     if (wrapper) {
       wrapper.destroy();
     }
+    mock.restore();
   });
 
   describe('the sidebar renders', () => {
     beforeEach(() => {
+      mock = new MockAdapter(axios);
       mountComponent();
     });
 
     it('open as default', () => {
       expect(wrapper.props('sidebarCollapsed')).toBe(true);
     });
+
+    it('should not render side bar assignee dropdown by default', () => {
+      expect(wrapper.find(SidebarAssignees).exists()).toBe(false);
+    });
+
+    it('should render side bar assignee dropdown if feature flag enabled', () => {
+      mountComponent({
+        mountMethod: mount,
+        alertAssignee: true,
+        alert: mockAlert,
+      });
+      expect(wrapper.find(SidebarAssignees).exists()).toBe(true);
+    });
   });
 });
diff --git a/spec/frontend/alert_management/components/alert_sidebar_status_spec.js b/spec/frontend/alert_management/components/alert_sidebar_status_spec.js
index d8d6634a46e..94643966a43 100644
--- a/spec/frontend/alert_management/components/alert_sidebar_status_spec.js
+++ b/spec/frontend/alert_management/components/alert_sidebar_status_spec.js
@@ -13,14 +13,8 @@ describe('Alert Details Sidebar Status', () => {
   const findStatusDropdownItem = () => wrapper.find(GlDropdownItem);
   const findStatusLoadingIcon = () => wrapper.find(GlLoadingIcon);
 
-  function mountComponent({
-    data,
-    sidebarCollapsed = true,
-    loading = false,
-    mountMethod = shallowMount,
-    stubs = {},
-  } = {}) {
-    wrapper = mountMethod(AlertSidebarStatus, {
+  function mountComponent({ data, sidebarCollapsed = true, loading = false, stubs = {} } = {}) {
+    wrapper = shallowMount(AlertSidebarStatus, {
       propsData: {
         alert: { ...mockAlert },
         ...data,
@@ -85,7 +79,7 @@ describe('Alert Details Sidebar Status', () => {
       jest.spyOn(wrapper.vm.$apollo, 'mutate').mockReturnValue(Promise.reject(new Error()));
       findStatusDropdownItem().vm.$emit('click');
       expect(findStatusLoadingIcon().exists()).toBe(false);
-      expect(wrapper.find('.gl-text-gray-700').text()).toBe('Triggered');
+      expect(wrapper.find('[data-testid="status"]').text()).toBe('Triggered');
     });
   });
 
diff --git a/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb b/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
new file mode 100644
index 00000000000..a025b3d344a
--- /dev/null
+++ b/spec/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
@@ -0,0 +1,167 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Mutations::AlertManagement::Alerts::SetAssignees do
+  let_it_be(:starting_assignee) { create(:user) }
+  let_it_be(:unassigned_user) { create(:user) }
+  let_it_be(:alert) { create(:alert_management_alert, assignees: [starting_assignee]) }
+  let_it_be(:project) { alert.project }
+
+  let(:current_user) { starting_assignee }
+  let(:assignee_usernames) { [unassigned_user.username] }
+  let(:operation_mode) { nil }
+
+  let(:args) do
+    {
+      project_path: project.full_path,
+      iid: alert.iid,
+      assignee_usernames: assignee_usernames,
+      operation_mode: operation_mode
+    }
+  end
+
+  before_all do
+    project.add_developer(starting_assignee)
+    project.add_developer(unassigned_user)
+  end
+
+  specify { expect(described_class).to require_graphql_authorizations(:update_alert_management_alert) }
+
+  describe '#resolve' do
+    let(:expected_assignees) { [unassigned_user] }
+
+    subject(:resolve) { mutation_for(project, current_user).resolve(args) }
+
+    shared_examples 'successful resolution' do
+      after do
+        alert.assignees = [starting_assignee]
+      end
+
+      it 'successfully resolves' do
+        expect(resolve).to eq(alert: alert.reload, errors: [])
+        expect(alert.assignees).to eq(expected_assignees)
+      end
+    end
+
+    shared_examples 'noop' do
+      it 'makes no changes' do
+        original_assignees = alert.assignees
+
+        expect(resolve).to eq(alert: alert.reload, errors: [])
+        expect(alert.assignees).to eq(original_assignees)
+      end
+    end
+
+    context 'when operation mode is not specified' do
+      it_behaves_like 'successful resolution'
+    end
+
+    context 'when user does not have permission to update alerts' do
+      let(:current_user) { create(:user) }
+
+      it 'raises an error if the resource is not accessible to the user' do
+        expect { subject }.to raise_error(Gitlab::Graphql::Errors::ResourceNotAvailable)
+      end
+    end
+
+    context 'for APPEND operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:append] }
+
+      # Only allow a single assignee
+      context 'when a different user is already assigned' do
+        it_behaves_like 'noop'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+
+        it_behaves_like 'noop'
+      end
+    end
+
+    context 'for REPLACE operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:replace] }
+
+      context 'when a different user is already assigned' do
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+        let(:expected_assignees) { [] }
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'successful resolution'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when multiple users are specified' do
+        let(:assignees) { [starting_assignee, unassigned_user] }
+        let(:assignee_usernames) { assignees.map(&:username) }
+        let(:expected_assignees) { [assignees.last] }
+
+        it_behaves_like 'successful resolution'
+      end
+    end
+
+    context 'for REMOVE operation' do
+      let(:operation_mode) { Types::MutationOperationModeEnum.enum[:remove] }
+
+      context 'when a different user is already assigned' do
+        it_behaves_like 'noop'
+      end
+
+      context 'when no users are specified' do
+        let(:assignee_usernames) { [] }
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when a user is specified and no user is assigned' do
+        before do
+          alert.assignees = []
+        end
+
+        it_behaves_like 'noop'
+      end
+
+      context 'when the specified user is already assigned to the alert' do
+        let(:assignee_usernames) { [starting_assignee.username] }
+        let(:expected_assignees) { [] }
+
+        it_behaves_like 'successful resolution'
+      end
+    end
+  end
+
+  def mutation_for(project, user)
+    described_class.new(object: project, context: { current_user: user }, field: nil)
+  end
+end
diff --git a/spec/lib/gitlab/kubernetes/helm/api_spec.rb b/spec/lib/gitlab/kubernetes/helm/api_spec.rb
index 1f925fd45af..0e4179d5887 100644
--- a/spec/lib/gitlab/kubernetes/helm/api_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/api_spec.rb
@@ -17,7 +17,8 @@ describe Gitlab::Kubernetes::Helm::API do
       name: application_name,
       chart: 'chart-name',
       rbac: rbac,
-      files: files
+      files: files,
+      local_tiller_enabled: true
     )
   end
 
@@ -142,7 +143,7 @@ describe Gitlab::Kubernetes::Helm::API do
     end
 
     context 'with a service account' do
-      let(:command) { Gitlab::Kubernetes::Helm::InitCommand.new(name: application_name, files: files, rbac: rbac) }
+      let(:command) { Gitlab::Kubernetes::Helm::InitCommand.new(name: application_name, files: files, rbac: rbac, local_tiller_enabled: true) }
 
       context 'rbac-enabled cluster' do
         let(:rbac) { true }
diff --git a/spec/lib/gitlab/kubernetes/helm/base_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/base_command_spec.rb
index 2a4a911cf38..f9bcb8abdb1 100644
--- a/spec/lib/gitlab/kubernetes/helm/base_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/base_command_spec.rb
@@ -11,25 +11,14 @@ describe Gitlab::Kubernetes::Helm::BaseCommand do
   let(:rbac) { false }
 
   let(:test_class) do
-    Class.new do
-      include Gitlab::Kubernetes::Helm::BaseCommand
-
+    Class.new(Gitlab::Kubernetes::Helm::BaseCommand) do
       def initialize(rbac)
-        @rbac = rbac
-      end
-
-      def name
-        "test-class-name"
-      end
-
-      def rbac?
-        @rbac
-      end
-
-      def files
-        {
-          some: 'value'
-        }
+        super(
+          name: 'test-class-name',
+          rbac: rbac,
+          files: { some: 'value' },
+          local_tiller_enabled: false
+        )
       end
     end
   end
diff --git a/spec/lib/gitlab/kubernetes/helm/delete_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/delete_command_spec.rb
index 95d60c18d56..2bf8b294821 100644
--- a/spec/lib/gitlab/kubernetes/helm/delete_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/delete_command_spec.rb
@@ -3,11 +3,12 @@
 require 'spec_helper'
 
 describe Gitlab::Kubernetes::Helm::DeleteCommand do
-  subject(:delete_command) { described_class.new(name: app_name, rbac: rbac, files: files) }
+  subject(:delete_command) { described_class.new(name: app_name, rbac: rbac, files: files, local_tiller_enabled: local_tiller_enabled) }
 
   let(:app_name) { 'app-name' }
   let(:rbac) { true }
   let(:files) { {} }
+  let(:local_tiller_enabled) { true }
 
   it_behaves_like 'helm command generator' do
     let(:commands) do
@@ -21,9 +22,7 @@ describe Gitlab::Kubernetes::Helm::DeleteCommand do
   end
 
   context 'tillerless feature disabled' do
-    before do
-      stub_feature_flags(managed_apps_local_tiller: false)
-    end
+    let(:local_tiller_enabled) { false }
 
     it_behaves_like 'helm command generator' do
       let(:commands) do
diff --git a/spec/lib/gitlab/kubernetes/helm/init_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/init_command_spec.rb
index 05d9b63d12b..61b8eb30b42 100644
--- a/spec/lib/gitlab/kubernetes/helm/init_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/init_command_spec.rb
@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 describe Gitlab::Kubernetes::Helm::InitCommand do
-  subject(:init_command) { described_class.new(name: application.name, files: files, rbac: rbac) }
+  subject(:init_command) { described_class.new(name: application.name, files: files, rbac: rbac, local_tiller_enabled: false) }
 
   let(:application) { create(:clusters_applications_helm) }
   let(:rbac) { false }
diff --git a/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb
index abd29e97505..6fc91300f5b 100644
--- a/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/install_command_spec.rb
@@ -12,7 +12,8 @@ describe Gitlab::Kubernetes::Helm::InstallCommand do
       version: version,
       repository: repository,
       preinstall: preinstall,
-      postinstall: postinstall
+      postinstall: postinstall,
+      local_tiller_enabled: local_tiller_enabled
     )
   end
 
@@ -22,6 +23,7 @@ describe Gitlab::Kubernetes::Helm::InstallCommand do
   let(:version) { '1.2.3' }
   let(:preinstall) { nil }
   let(:postinstall) { nil }
+  let(:local_tiller_enabled) { true }
 
   it_behaves_like 'helm command generator' do
     let(:commands) do
@@ -51,9 +53,7 @@ describe Gitlab::Kubernetes::Helm::InstallCommand do
   end
 
   context 'tillerless feature disabled' do
-    before do
-      stub_feature_flags(managed_apps_local_tiller: false)
-    end
+    let(:local_tiller_enabled) { false }
 
     let(:tls_flags) do
       <<~EOS.squish
diff --git a/spec/lib/gitlab/kubernetes/helm/patch_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/patch_command_spec.rb
index eee842fa7d6..8d965a25f84 100644
--- a/spec/lib/gitlab/kubernetes/helm/patch_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/patch_command_spec.rb
@@ -7,6 +7,7 @@ describe Gitlab::Kubernetes::Helm::PatchCommand do
   let(:repository) { 'https://repository.example.com' }
   let(:rbac) { false }
   let(:version) { '1.2.3' }
+  let(:local_tiller_enabled) { true }
 
   subject(:patch_command) do
     described_class.new(
@@ -15,14 +16,13 @@ describe Gitlab::Kubernetes::Helm::PatchCommand do
       rbac: rbac,
       files: files,
       version: version,
-      repository: repository
+      repository: repository,
+      local_tiller_enabled: local_tiller_enabled
     )
   end
 
   context 'when local tiller feature is disabled' do
-    before do
-      stub_feature_flags(managed_apps_local_tiller: false)
-    end
+    let(:local_tiller_enabled) { false }
 
     let(:tls_flags) do
       <<~EOS.squish
diff --git a/spec/lib/gitlab/kubernetes/helm/reset_command_spec.rb b/spec/lib/gitlab/kubernetes/helm/reset_command_spec.rb
index 981bb4e4abf..3773c428713 100644
--- a/spec/lib/gitlab/kubernetes/helm/reset_command_spec.rb
+++ b/spec/lib/gitlab/kubernetes/helm/reset_command_spec.rb
@@ -3,7 +3,7 @@
 require 'spec_helper'
 
 describe Gitlab::Kubernetes::Helm::ResetCommand do
-  subject(:reset_command) { described_class.new(name: name, rbac: rbac, files: files) }
+  subject(:reset_command) { described_class.new(name: name, rbac: rbac, files: files, local_tiller_enabled: false) }
 
   let(:rbac) { true }
   let(:name) { 'helm' }
diff --git a/spec/requests/api/graphql/mutations/alert_management/alerts/set_assignees_spec.rb b/spec/requests/api/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
new file mode 100644
index 00000000000..6663281e093
--- /dev/null
+++ b/spec/requests/api/graphql/mutations/alert_management/alerts/set_assignees_spec.rb
@@ -0,0 +1,65 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'Setting assignees of an alert' do
+  include GraphqlHelpers
+
+  let_it_be(:project) { create(:project) }
+  let_it_be(:current_user) { create(:user) }
+  let_it_be(:alert) { create(:alert_management_alert, project: project) }
+  let(:input) { { assignee_usernames: [current_user.username] } }
+
+  let(:mutation) do
+    graphql_mutation(
+      :alert_set_assignees,
+      { project_path: project.full_path, iid: alert.iid.to_s }.merge(input),
+      <<~QL
+       clientMutationId
+       errors
+       alert {
+         assignees {
+           nodes {
+             username
+           }
+         }
+       }
+      QL
+    )
+  end
+
+  let(:mutation_response) { graphql_mutation_response(:alert_set_assignees) }
+
+  before_all do
+    project.add_developer(current_user)
+  end
+
+  it 'updates the assignee of the alert' do
+    post_graphql_mutation(mutation, current_user: current_user)
+
+    expect(response).to have_gitlab_http_status(:success)
+    expect(mutation_response['alert']['assignees']['nodes'].first['username']).to eq(current_user.username)
+    expect(alert.reload.assignees).to contain_exactly(current_user)
+  end
+
+  context 'with operation_mode specified' do
+    let(:input) do
+      {
+        assignee_usernames: [current_user.username],
+        operation_mode: Types::MutationOperationModeEnum.enum[:remove]
+      }
+    end
+
+    before do
+      alert.assignees = [current_user]
+    end
+
+    it 'updates the assignee of the alert' do
+      post_graphql_mutation(mutation, current_user: current_user)
+
+      expect(response).to have_gitlab_http_status(:success)
+      expect(mutation_response['alert']['assignees']['nodes']).to be_empty
+      expect(alert.reload.assignees).to be_empty
+    end
+  end
+end
diff --git a/spec/services/alert_management/alerts/update_service_spec.rb b/spec/services/alert_management/alerts/update_service_spec.rb
new file mode 100644
index 00000000000..055b2f6585a
--- /dev/null
+++ b/spec/services/alert_management/alerts/update_service_spec.rb
@@ -0,0 +1,81 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe AlertManagement::Alerts::UpdateService do
+  let_it_be(:user_with_permissions) { create(:user) }
+  let_it_be(:user_without_permissions) { create(:user) }
+  let_it_be(:alert, reload: true) { create(:alert_management_alert) }
+  let_it_be(:project) { alert.project }
+
+  let(:current_user) { user_with_permissions }
+  let(:params) { {} }
+
+  let(:service) { described_class.new(alert, current_user, params) }
+
+  before_all do
+    project.add_developer(user_with_permissions)
+  end
+
+  describe '#execute' do
+    subject(:response) { service.execute }
+
+    context 'when user does not have permission to update alerts' do
+      let(:current_user) { user_without_permissions }
+
+      it 'results in an error' do
+        expect(response).to be_error
+        expect(response.message).to eq('You have no permissions')
+      end
+    end
+
+    context 'when no parameters are included' do
+      it 'results in an error' do
+        expect(response).to be_error
+        expect(response.message).to eq('Please provide attributes to update')
+      end
+    end
+
+    context 'when an error occures during update' do
+      let(:params) { { title: nil } }
+
+      it 'results in an error' do
+        expect(response).to be_error
+        expect(response.message).to eq("Title can't be blank")
+      end
+    end
+
+    context 'when a model attribute is included' do
+      let(:params) { { title: 'This is an updated alert.' } }
+
+      it 'updates the attribute' do
+        original_title = alert.title
+
+        expect { response }.to change { alert.title }.from(original_title).to(params[:title])
+        expect(response).to be_success
+      end
+    end
+
+    context 'when assignees are included' do
+      let(:params) { { assignees: [user_with_permissions] } }
+
+      after do
+        alert.assignees = []
+      end
+
+      it 'assigns the user' do
+        expect { response }.to change { alert.reload.assignees }.from([]).to(params[:assignees])
+        expect(response).to be_success
+      end
+
+      context 'with multiple users included' do
+        let(:params) { { assignees: [user_with_permissions, user_without_permissions] } }
+
+        it 'assigns the first permissioned user' do
+          expect { response }.to change { alert.reload.assignees }.from([]).to([user_with_permissions])
+          expect(response).to be_success
+        end
+      end
+    end
+  end
+end
diff --git a/spec/support/shared_examples/models/cluster_application_helm_cert_shared_examples.rb b/spec/support/shared_examples/models/cluster_application_helm_cert_shared_examples.rb
index fa6b0c3afdd..239588d3b2f 100644
--- a/spec/support/shared_examples/models/cluster_application_helm_cert_shared_examples.rb
+++ b/spec/support/shared_examples/models/cluster_application_helm_cert_shared_examples.rb
@@ -54,7 +54,7 @@ RSpec.shared_examples 'cluster application helm specs' do |application_name|
 
     context 'managed_apps_local_tiller feature flag is enabled' do
       before do
-        stub_feature_flags(managed_apps_local_tiller: true)
+        stub_feature_flags(managed_apps_local_tiller: application.cluster.clusterable)
       end
 
       it 'does not include cert files' do
diff --git a/spec/support/shared_examples/models/cluster_application_initial_status_shared_examples.rb b/spec/support/shared_examples/models/cluster_application_initial_status_shared_examples.rb
index 0b21e9a3aa7..7f0c60d4204 100644
--- a/spec/support/shared_examples/models/cluster_application_initial_status_shared_examples.rb
+++ b/spec/support/shared_examples/models/cluster_application_initial_status_shared_examples.rb
@@ -18,7 +18,7 @@ RSpec.shared_examples 'cluster application initial status specs' do
 
     context 'local tiller feature flag is enabled' do
       before do
-        stub_feature_flags(managed_apps_local_tiller: true)
+        stub_feature_flags(managed_apps_local_tiller: cluster.clusterable)
       end
 
       it 'sets a default status' do
diff --git a/spec/support/shared_examples/models/cluster_application_status_shared_examples.rb b/spec/support/shared_examples/models/cluster_application_status_shared_examples.rb
index a259c47ff86..0efa5e56199 100644
--- a/spec/support/shared_examples/models/cluster_application_status_shared_examples.rb
+++ b/spec/support/shared_examples/models/cluster_application_status_shared_examples.rb
@@ -66,7 +66,7 @@ RSpec.shared_examples 'cluster application status specs' do |application_name|
 
       context 'managed_apps_local_tiller feature flag enabled' do
         before do
-          stub_feature_flags(managed_apps_local_tiller: true)
+          stub_feature_flags(managed_apps_local_tiller: subject.cluster.clusterable)
         end
 
         it 'does not update the helm version' do