CLI tools: introduce commands that enable and disable free disk space monitoring (#8743)

* Closes #8741

References #8740

---------

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>

deps/rabbit/src/rabbit_disk_monitor.erl

@@ -161,16 +161,26 @@ handle_call({set_min_check_interval, MinInterval}, _From, State) ->
 handle_call({set_max_check_interval, MaxInterval}, _From, State) ->
     {reply, ok, set_max_check_interval(MaxInterval, State)};
 
-handle_call({set_enabled, _Enabled = true}, _From, State) ->
+handle_call({set_enabled, _Enabled = true}, _From, State = #state{enabled = true}) ->
     _ = start_timer(set_disk_limits(State, State#state.limit)),
-    rabbit_log:info("Free disk space monitor was enabled"),
+    rabbit_log:info("Free disk space monitor was already enabled"),
     {reply, ok, State#state{enabled = true}};
 
-handle_call({set_enabled, _Enabled = false}, _From, State) ->
+handle_call({set_enabled, _Enabled = true}, _From, State = #state{enabled = false}) ->
+  _ = start_timer(set_disk_limits(State, State#state.limit)),
+  rabbit_log:info("Free disk space monitor was manually enabled"),
+  {reply, ok, State#state{enabled = true}};
+
+handle_call({set_enabled, _Enabled = false}, _From, State = #state{enabled = true}) ->
     _ = erlang:cancel_timer(State#state.timer),
     rabbit_log:info("Free disk space monitor was manually disabled"),
     {reply, ok, State#state{enabled = false}};
 
+handle_call({set_enabled, _Enabled = false}, _From, State = #state{enabled = false}) ->
+  _ = erlang:cancel_timer(State#state.timer),
+  rabbit_log:info("Free disk space monitor was already disabled"),
+  {reply, ok, State#state{enabled = false}};
+
 handle_call(_Request, _From, State) ->
     {noreply, State}.
 

deps/rabbitmq_cli/lib/rabbitmq/cli/ctl/commands/disable_free_disk_space_monitoring_command.ex

@@ -0,0 +1,61 @@
+## This Source Code Form is subject to the terms of the Mozilla Public
+## License, v. 2.0. If a copy of the MPL was not distributed with this
+## file, You can obtain one at https://mozilla.org/MPL/2.0/.
+##
+## Copyright (c) 2007-2023 VMware, Inc. or its affiliates.  All rights reserved.
+
+defmodule RabbitMQ.CLI.Ctl.Commands.DisableFreeDiskSpaceMonitoringCommand do
+  alias RabbitMQ.CLI.Core.DocGuide
+
+  @behaviour RabbitMQ.CLI.CommandBehaviour
+
+  @default_timeout 60_000
+
+  def scopes(), do: [:ctl, :diagnostics]
+
+  def switches(), do: [unit: :string, timeout: :integer]
+  def aliases(), do: [t: :timeout]
+
+  def merge_defaults(args, opts) do
+    timeout =
+      case opts[:timeout] do
+        nil -> @default_timeout
+        :infinity -> @default_timeout
+        other -> other
+      end
+
+    {args, Map.merge(%{timeout: timeout}, opts)}
+  end
+
+  def validate(args, _) when length(args) > 0 do
+    {:validation_failure, :too_many_args}
+  end
+
+  def validate(_, _), do: :ok
+
+  use RabbitMQ.CLI.Core.RequiresRabbitAppRunning
+
+  def run([], %{node: node_name, timeout: timeout}) do
+    :rabbit_misc.rpc_call(node_name, :rabbit_disk_monitor, :set_enabled, [false], timeout)
+  end
+
+  use RabbitMQ.CLI.DefaultOutput
+
+  def formatter(), do: RabbitMQ.CLI.Formatters.String
+
+  def usage, do: "disable_free_disk_space_monitoring"
+
+  def usage_doc_guides() do
+    [
+      DocGuide.alarms(),
+      DocGuide.monitoring()
+    ]
+  end
+
+  def help_section(), do: :observability_and_health_checks
+
+  def description(), do: "Disables free disk space monitoring on a node"
+
+  def banner(_, %{node: node_name}),
+    do: "Disabling free disk space monitoring on node #{node_name}..."
+end

deps/rabbitmq_cli/lib/rabbitmq/cli/ctl/commands/enable_free_disk_space_monitoring_command.ex

@@ -0,0 +1,61 @@
+## This Source Code Form is subject to the terms of the Mozilla Public
+## License, v. 2.0. If a copy of the MPL was not distributed with this
+## file, You can obtain one at https://mozilla.org/MPL/2.0/.
+##
+## Copyright (c) 2007-2023 VMware, Inc. or its affiliates.  All rights reserved.
+
+defmodule RabbitMQ.CLI.Ctl.Commands.EnableFreeDiskSpaceMonitoringCommand do
+  alias RabbitMQ.CLI.Core.DocGuide
+
+  @behaviour RabbitMQ.CLI.CommandBehaviour
+
+  @default_timeout 60_000
+
+  def scopes(), do: [:ctl, :diagnostics]
+
+  def switches(), do: [unit: :string, timeout: :integer]
+  def aliases(), do: [t: :timeout]
+
+  def merge_defaults(args, opts) do
+    timeout =
+      case opts[:timeout] do
+        nil -> @default_timeout
+        :infinity -> @default_timeout
+        other -> other
+      end
+
+    {args, Map.merge(%{timeout: timeout}, opts)}
+  end
+
+  def validate(args, _) when length(args) > 0 do
+    {:validation_failure, :too_many_args}
+  end
+
+  def validate(_, _), do: :ok
+
+  use RabbitMQ.CLI.Core.RequiresRabbitAppRunning
+
+  def run([], %{node: node_name, timeout: timeout}) do
+    :rabbit_misc.rpc_call(node_name, :rabbit_disk_monitor, :set_enabled, [true], timeout)
+  end
+
+  use RabbitMQ.CLI.DefaultOutput
+
+  def formatter(), do: RabbitMQ.CLI.Formatters.String
+
+  def usage, do: "enable_free_disk_space_monitoring"
+
+  def usage_doc_guides() do
+    [
+      DocGuide.alarms(),
+      DocGuide.monitoring()
+    ]
+  end
+
+  def help_section(), do: :observability_and_health_checks
+
+  def description(), do: "[Re-]enables free disk space monitoring on a node"
+
+  def banner(_, %{node: node_name}),
+    do: "[Re-]enabling free disk space monitoring on node #{node_name}..."
+end

deps/rabbitmq_cli/test/ctl/disable_disk_free_space_monitoring_command_test.exs

@@ -0,0 +1,39 @@
+## This Source Code Form is subject to the terms of the Mozilla Public
+## License, v. 2.0. If a copy of the MPL was not distributed with this
+## file, You can obtain one at https://mozilla.org/MPL/2.0/.
+##
+## Copyright (c) 2007-2023 VMware, Inc. or its affiliates.  All rights reserved.
+
+defmodule DisableDiskFreeSpaceMonitoringCommandTest do
+  use ExUnit.Case, async: false
+  import TestHelper
+
+  @command RabbitMQ.CLI.Ctl.Commands.DisableFreeDiskSpaceMonitoringCommand
+
+  setup_all do
+    RabbitMQ.CLI.Core.Distribution.start()
+
+    :ok
+  end
+
+  setup do
+    {:ok, opts: %{node: get_rabbit_hostname(), timeout: 60_000}}
+  end
+
+  test "validate: with extra arguments returns an arg count error", context do
+    assert @command.validate(["extra"], context[:opts]) == {:validation_failure, :too_many_args}
+  end
+
+  test "run: request to a named, active node succeeds", context do
+    assert @command.run([], context[:opts])
+  end
+
+  test "run: request to a non-existent node returns a badrpc" do
+    opts = %{node: :jake@thedog, timeout: 200}
+    assert match?({:badrpc, _}, @command.run([], opts))
+  end
+
+  test "banner", context do
+    assert @command.banner([], context[:opts]) =~ ~r/Disabling free disk space monitoring on node/
+  end
+end

deps/rabbitmq_cli/test/ctl/enable_disk_free_space_monitoring_command_test.exs

@@ -0,0 +1,40 @@
+## This Source Code Form is subject to the terms of the Mozilla Public
+## License, v. 2.0. If a copy of the MPL was not distributed with this
+## file, You can obtain one at https://mozilla.org/MPL/2.0/.
+##
+## Copyright (c) 2007-2023 VMware, Inc. or its affiliates.  All rights reserved.
+
+defmodule EnableDiskFreeSpaceMonitoringCommandTest do
+  use ExUnit.Case, async: false
+  import TestHelper
+
+  @command RabbitMQ.CLI.Ctl.Commands.EnableFreeDiskSpaceMonitoringCommand
+
+  setup_all do
+    RabbitMQ.CLI.Core.Distribution.start()
+
+    :ok
+  end
+
+  setup do
+    {:ok, opts: %{node: get_rabbit_hostname(), timeout: 60_000}}
+  end
+
+  test "validate: with extra arguments returns an arg count error", context do
+    assert @command.validate(["extra"], context[:opts]) == {:validation_failure, :too_many_args}
+  end
+
+  test "run: request to a named, active node succeeds", context do
+    assert @command.run([], context[:opts])
+  end
+
+  test "run: request to a non-existent node returns a badrpc" do
+    opts = %{node: :jake@thedog, timeout: 200}
+    assert match?({:badrpc, _}, @command.run([], opts))
+  end
+
+  test "banner", context do
+    assert @command.banner([], context[:opts]) =~
+             ~r/\[Re\-\]enabling free disk space monitoring on node/
+  end
+end