Alerting: Keep extra configurations on main config update (#106958)

pkg/services/ngalert/notifier/alertmanager_config.go

@@ -324,6 +324,15 @@ func (moa *MultiOrgAlertmanager) SaveAndApplyAlertmanagerConfiguration(ctx conte
 	}
 	cleanPermissionsErr := err
 
+	if previousConfig != nil {
+		// If there is a previous configuration, we need to copy its extra configs to the new one.
+		extraConfigs, err := extractExtraConfigs(previousConfig.AlertmanagerConfiguration)
+		if err != nil {
+			return fmt.Errorf("failed to extract extra configs from previous configuration: %w", err)
+		}
+		config.ExtraConfigs = extraConfigs
+	}
+
 	if err := moa.Crypto.ProcessSecureSettings(ctx, org, config.AlertmanagerConfig.Receivers); err != nil {
 		return fmt.Errorf("failed to post process Alertmanager configuration: %w", err)
 	}
@@ -572,3 +581,18 @@ func extractReceiverNames(rawConfig string) (sets.Set[string], error) {
 
 	return receiverNames, nil
 }
+
+// extractExtraConfigs extracts encrypted (does not decrypt) extra configurations from the raw Alertmanager config.
+func extractExtraConfigs(rawConfig string) ([]definitions.ExtraConfiguration, error) {
+	// Slimmed down version of the Alertmanager configuration to extract extra configs.
+	type extraConfigUserConfig struct {
+		ExtraConfigs []definitions.ExtraConfiguration `yaml:"extra_config,omitempty" json:"extra_config,omitempty"`
+	}
+
+	cfg := &extraConfigUserConfig{}
+	if err := json.Unmarshal([]byte(rawConfig), cfg); err != nil {
+		return nil, fmt.Errorf("unable to parse Alertmanager configuration: %w", err)
+	}
+
+	return cfg.ExtraConfigs, nil
+}

pkg/services/ngalert/notifier/alertmanager_config_test.go

@@ -150,6 +150,264 @@ receivers:
 	})
 }
 
+func TestMultiOrgAlertmanager_SaveAndApplyAlertmanagerConfiguration(t *testing.T) {
+	orgID := int64(1)
+	ctx := context.Background()
+
+	t.Run("SaveAndApplyAlertmanagerConfiguration preserves existing extra configs", func(t *testing.T) {
+		mam := setupMam(t, nil)
+		require.NoError(t, mam.LoadAndSyncAlertmanagersForOrgs(ctx))
+
+		extraConfig := definitions.ExtraConfiguration{
+			Identifier:    "test-extra-config",
+			MergeMatchers: amconfig.Matchers{&labels.Matcher{Type: labels.MatchEqual, Name: "env", Value: "test"}},
+			TemplateFiles: map[string]string{"test.tmpl": "{{ define \"test\" }}Test{{ end }}"},
+			AlertmanagerConfig: `route:
+  receiver: extra-receiver
+receivers:
+  - name: extra-receiver`,
+		}
+
+		err := mam.SaveAndApplyExtraConfiguration(ctx, orgID, extraConfig)
+		require.NoError(t, err)
+
+		// Verify extra config was saved
+		gettableConfig, err := mam.GetAlertmanagerConfiguration(ctx, orgID, false, false)
+		require.NoError(t, err)
+		require.Len(t, gettableConfig.ExtraConfigs, 1)
+		require.Equal(t, extraConfig.Identifier, gettableConfig.ExtraConfigs[0].Identifier)
+
+		// Apply a new main configuration
+		newMainConfig := definitions.PostableUserConfig{
+			AlertmanagerConfig: definitions.PostableApiAlertingConfig{
+				Config: definitions.Config{
+					Route: &definitions.Route{
+						Receiver: "main-receiver",
+					},
+				},
+				Receivers: []*definitions.PostableApiReceiver{
+					{
+						Receiver: amconfig.Receiver{
+							Name: "main-receiver",
+						},
+						PostableGrafanaReceivers: definitions.PostableGrafanaReceivers{
+							GrafanaManagedReceivers: []*definitions.PostableGrafanaReceiver{
+								{
+									Name:     "main-receiver",
+									Type:     "email",
+									Settings: definitions.RawMessage(`{"addresses": "me@grafana.com"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err = mam.SaveAndApplyAlertmanagerConfiguration(ctx, orgID, newMainConfig)
+		require.NoError(t, err)
+
+		// Verify that the extra config is still present after applying the new main config
+		updatedConfig, err := mam.GetAlertmanagerConfiguration(ctx, orgID, false, false)
+		require.NoError(t, err)
+		require.Len(t, updatedConfig.ExtraConfigs, 1)
+		require.Equal(t, extraConfig.Identifier, updatedConfig.ExtraConfigs[0].Identifier)
+		require.Equal(t, extraConfig.TemplateFiles, updatedConfig.ExtraConfigs[0].TemplateFiles)
+
+		// Verify the main config was updated
+		require.Equal(t, "main-receiver", updatedConfig.AlertmanagerConfig.Route.Receiver)
+		require.Len(t, updatedConfig.AlertmanagerConfig.Receivers, 1)
+		require.Equal(t, "main-receiver", updatedConfig.AlertmanagerConfig.Receivers[0].Name)
+	})
+
+	t.Run("SaveAndApplyAlertmanagerConfiguration handles missing extra_configs field", func(t *testing.T) {
+		mam := setupMam(t, nil)
+		require.NoError(t, mam.LoadAndSyncAlertmanagersForOrgs(ctx))
+
+		// Apply initial config without extra_configs field
+		initialConfig := definitions.PostableUserConfig{
+			AlertmanagerConfig: definitions.PostableApiAlertingConfig{
+				Config: definitions.Config{
+					Route: &definitions.Route{
+						Receiver: "initial-receiver",
+					},
+				},
+				Receivers: []*definitions.PostableApiReceiver{
+					{
+						Receiver: amconfig.Receiver{
+							Name: "initial-receiver",
+						},
+						PostableGrafanaReceivers: definitions.PostableGrafanaReceivers{
+							GrafanaManagedReceivers: []*definitions.PostableGrafanaReceiver{
+								{
+									Name:     "initial-receiver",
+									Type:     "email",
+									Settings: definitions.RawMessage(`{"addresses": "initial@grafana.com"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err := mam.SaveAndApplyAlertmanagerConfiguration(ctx, orgID, initialConfig)
+		require.NoError(t, err)
+
+		// Apply a new main configuration
+		newMainConfig := definitions.PostableUserConfig{
+			AlertmanagerConfig: definitions.PostableApiAlertingConfig{
+				Config: definitions.Config{
+					Route: &definitions.Route{
+						Receiver: "main-receiver",
+					},
+				},
+				Receivers: []*definitions.PostableApiReceiver{
+					{
+						Receiver: amconfig.Receiver{
+							Name: "main-receiver",
+						},
+						PostableGrafanaReceivers: definitions.PostableGrafanaReceivers{
+							GrafanaManagedReceivers: []*definitions.PostableGrafanaReceiver{
+								{
+									Name:     "main-receiver",
+									Type:     "email",
+									Settings: definitions.RawMessage(`{"addresses": "me@grafana.com"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err = mam.SaveAndApplyAlertmanagerConfiguration(ctx, orgID, newMainConfig)
+		require.NoError(t, err)
+
+		// Verify that no extra configs are present and main config was updated
+		updatedConfig, err := mam.GetAlertmanagerConfiguration(ctx, orgID, false, false)
+		require.NoError(t, err)
+		require.Len(t, updatedConfig.ExtraConfigs, 0)
+		require.Equal(t, "main-receiver", updatedConfig.AlertmanagerConfig.Route.Receiver)
+	})
+
+	t.Run("SaveAndApplyAlertmanagerConfiguration handles empty extra_configs array", func(t *testing.T) {
+		mam := setupMam(t, nil)
+		require.NoError(t, mam.LoadAndSyncAlertmanagersForOrgs(ctx))
+
+		// Apply initial config with empty extra_configs
+		initialConfig := definitions.PostableUserConfig{
+			AlertmanagerConfig: definitions.PostableApiAlertingConfig{
+				Config: definitions.Config{
+					Route: &definitions.Route{
+						Receiver: "initial-receiver",
+					},
+				},
+				Receivers: []*definitions.PostableApiReceiver{
+					{
+						Receiver: amconfig.Receiver{
+							Name: "initial-receiver",
+						},
+						PostableGrafanaReceivers: definitions.PostableGrafanaReceivers{
+							GrafanaManagedReceivers: []*definitions.PostableGrafanaReceiver{
+								{
+									Name:     "initial-receiver",
+									Type:     "email",
+									Settings: definitions.RawMessage(`{"addresses": "initial@grafana.com"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+			ExtraConfigs: []definitions.ExtraConfiguration{}, // Empty array
+		}
+
+		err := mam.SaveAndApplyAlertmanagerConfiguration(ctx, orgID, initialConfig)
+		require.NoError(t, err)
+
+		// Apply a new main configuration
+		newMainConfig := definitions.PostableUserConfig{
+			AlertmanagerConfig: definitions.PostableApiAlertingConfig{
+				Config: definitions.Config{
+					Route: &definitions.Route{
+						Receiver: "main-receiver",
+					},
+				},
+				Receivers: []*definitions.PostableApiReceiver{
+					{
+						Receiver: amconfig.Receiver{
+							Name: "main-receiver",
+						},
+						PostableGrafanaReceivers: definitions.PostableGrafanaReceivers{
+							GrafanaManagedReceivers: []*definitions.PostableGrafanaReceiver{
+								{
+									Name:     "main-receiver",
+									Type:     "email",
+									Settings: definitions.RawMessage(`{"addresses": "me@grafana.com"}`),
+								},
+							},
+						},
+					},
+				},
+			},
+		}
+
+		err = mam.SaveAndApplyAlertmanagerConfiguration(ctx, orgID, newMainConfig)
+		require.NoError(t, err)
+
+		// Verify that no extra configs are present and main config was updated
+		updatedConfig, err := mam.GetAlertmanagerConfiguration(ctx, orgID, false, false)
+		require.NoError(t, err)
+		require.Len(t, updatedConfig.ExtraConfigs, 0)
+		require.Equal(t, "main-receiver", updatedConfig.AlertmanagerConfig.Route.Receiver)
+	})
+}
+
+func TestExtractExtraConfigs(t *testing.T) {
+	t.Run("extracts extra configs from JSON", func(t *testing.T) {
+		jsonConfig := `{
+			"extra_config": [
+				{
+					"identifier": "test-config",
+					"merge_matchers": [],
+					"template_files": {"test.tmpl": "test"},
+					"alertmanager_config": "route:\n  receiver: test"
+				}
+			]
+		}`
+
+		extraConfigs, err := extractExtraConfigs(jsonConfig)
+		require.NoError(t, err)
+		require.Len(t, extraConfigs, 1)
+		require.Equal(t, "test-config", extraConfigs[0].Identifier)
+	})
+
+	t.Run("handles missing extra_config field", func(t *testing.T) {
+		jsonConfig := `{"alertmanager_config": {"route": {"receiver": "test"}}}`
+
+		extraConfigs, err := extractExtraConfigs(jsonConfig)
+		require.NoError(t, err)
+		require.Len(t, extraConfigs, 0)
+	})
+
+	t.Run("handles empty extra_config array", func(t *testing.T) {
+		jsonConfig := `{"extra_config": []}`
+
+		extraConfigs, err := extractExtraConfigs(jsonConfig)
+		require.NoError(t, err)
+		require.Len(t, extraConfigs, 0)
+	})
+
+	t.Run("handles null extra_config", func(t *testing.T) {
+		jsonConfig := `{"extra_config": null}`
+
+		extraConfigs, err := extractExtraConfigs(jsonConfig)
+		require.NoError(t, err)
+		require.Len(t, extraConfigs, 0)
+	})
+}
+
 func TestMultiOrgAlertmanager_DeleteExtraConfiguration(t *testing.T) {
 	orgID := int64(1)