introduce a cli list_channel_interceptors_command to list all active

channel interceptors with their configured meta information

Author: Ayanda-D

deps/rabbit/src/rabbit_channel_interceptor.erl

@@ -9,7 +9,7 @@
 
 -include_lib("rabbit_common/include/rabbit.hrl").
 
--export([init/1, intercept_in/3]).
+-export([init/1, intercept_in/3, list/0]).
 
 -behaviour(rabbit_registry_class).
 
@@ -37,6 +37,10 @@ added_to_rabbit_registry(_Type, _ModuleName) ->
 removed_from_rabbit_registry(_Type) ->
     rabbit_channel:refresh_interceptors().
 
+list() ->
+    Mods = [M || {_, M} <- rabbit_registry:lookup_all(channel_interceptor)],
+    [[{name, Mod}, {applies_to, Mod:applies_to()}, {priority, priority(Mod)}] || Mod <- Mods].
+
 init(Ch) ->
     Mods = [M || {_, M} <- rabbit_registry:lookup_all(channel_interceptor)],
     Sorted = lists:sort(fun(A, B) -> priority(A) =< priority(B) end, Mods),

deps/rabbit/test/dummy_interceptor.erl …/rabbit_common/src/dummy_interceptor.erldeps/rabbit/test/dummy_interceptor.erl renamed to deps/rabbit_common/src/dummy_interceptor.erl deps/rabbit/test/dummy_interceptor.erl renamed to deps/rabbit_common/src/dummy_interceptor.erl

@@ -6,7 +6,7 @@
 -include_lib("rabbit_common/include/rabbit_framing.hrl").
 
 
--compile(export_all).
+-export([init/1, description/0, intercept/3, applies_to/0]).
 
 init(_Ch) ->
     undefined.

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

@@ -0,0 +1,44 @@
+## 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) 2007-2026 Broadcom. All Rights Reserved. The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries. All rights reserved.
+
+defmodule RabbitMQ.CLI.Ctl.Commands.ListChannelInterceptorsCommand do
+  @behaviour RabbitMQ.CLI.CommandBehaviour
+
+  def scopes(), do: [:ctl, :diagnostics]
+
+  use RabbitMQ.CLI.Core.AcceptsDefaultSwitchesAndTimeout
+  use RabbitMQ.CLI.Core.AcceptsNoPositionalArguments
+  use RabbitMQ.CLI.Core.RequiresRabbitAppRunning
+
+  def merge_defaults(args, opts) do
+    {args, Map.merge(%{table_headers: true}, opts)}
+  end
+
+  def run([], %{node: node_name, timeout: timeout}) do
+    case :rabbit_misc.rpc_call(node_name, :rabbit_channel_interceptor, :list, [], timeout) do
+      {:badrpc, _} = err ->
+        err
+
+      interceptors ->
+        Enum.map(interceptors, fn info ->
+          Keyword.update!(info, :applies_to, &Enum.join(&1, ", "))
+        end)
+    end
+  end
+
+  use RabbitMQ.CLI.DefaultOutput
+
+  def formatter(), do: RabbitMQ.CLI.Formatters.Table
+
+  def usage, do: "list_channel_interceptors [--no-table-headers]"
+
+  def help_section(), do: :observability_and_health_checks
+
+  def description(),
+    do: "Lists registered channel interceptors with their name, intercepted AMQP operations, and priority"
+
+  def banner(_, _), do: "Listing channel interceptors ..."
+end

deps/rabbitmq_cli/test/ctl/list_channel_interceptors_command_test.exs

@@ -0,0 +1,87 @@
+## 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) 2007-2026 Broadcom. All Rights Reserved. The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries. All rights reserved.
+
+defmodule ListChannelInterceptorsCommandTest do
+  use ExUnit.Case, async: false
+  import TestHelper
+
+  @command RabbitMQ.CLI.Ctl.Commands.ListChannelInterceptorsCommand
+
+  setup_all do
+    RabbitMQ.CLI.Core.Distribution.start()
+
+    :ok
+  end
+
+  setup context do
+    {
+      :ok,
+      opts: %{
+        node: get_rabbit_hostname(),
+        timeout: context[:test_timeout] || :infinity
+      }
+    }
+  end
+
+  test "merge_defaults: adds table_headers true to opts", context do
+    {args, opts} = @command.merge_defaults([], context[:opts])
+    assert args == []
+    assert opts[:table_headers] == true
+  end
+
+  test "validate: accepts no positional arguments", context do
+    assert @command.validate([], context[:opts]) == :ok
+  end
+
+  test "validate: rejects any positional arguments", context do
+    assert @command.validate(["extra"], context[:opts]) ==
+             {:validation_failure, :too_many_args}
+  end
+
+  test "run: on a bad RabbitMQ node, returns a badrpc" do
+    opts = %{node: :jake@thedog, timeout: 200}
+    assert match?({:badrpc, _}, @command.run([], opts))
+  end
+
+  @tag test_timeout: :infinity
+  test "run: with no interceptors registered, returns an empty list", context do
+    result = @command.run([], context[:opts])
+    assert result == []
+  end
+
+  @tag test_timeout: :infinity
+  test "run: registered interceptors are listed with applies_to joined as a string", context do
+    node = get_rabbit_hostname()
+
+    :ok =
+      :rabbit_misc.rpc_call(
+        node,
+        :rabbit_registry,
+        :register,
+        [:channel_interceptor, <<"test interceptor">>, :dummy_interceptor]
+      )
+
+    try do
+      result = @command.run([], context[:opts])
+      assert is_list(result)
+      interceptor = Enum.find(result, fn info -> info[:name] == :dummy_interceptor end)
+      assert interceptor != nil
+      assert is_binary(interceptor[:applies_to])
+      assert is_integer(interceptor[:priority])
+    after
+      :rabbit_misc.rpc_call(
+        node,
+        :rabbit_registry,
+        :unregister,
+        [:channel_interceptor, <<"test interceptor">>]
+      )
+    end
+  end
+
+  test "banner: returns the expected string", context do
+    assert @command.banner([], context[:opts]) == "Listing channel interceptors ..."
+  end
+end