Require --force to enable experimental FF

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

@@ -7,15 +7,18 @@
 defmodule RabbitMQ.CLI.Ctl.Commands.EnableFeatureFlagCommand do
   @behaviour RabbitMQ.CLI.CommandBehaviour
 
-  def merge_defaults(args, opts), do: {args, opts}
+  def switches(), do: [force: :boolean]
+  def aliases(), do: [f: :force]
 
-  def validate([], _), do: {:validation_failure, :not_enough_args}
-  def validate([_ | _] = args, _) when length(args) > 1, do: {:validation_failure, :too_many_args}
+  def merge_defaults(args, opts), do: { args, Map.merge(%{force: false}, opts) }
 
-  def validate([""], _),
+  def validate([], _opts), do: {:validation_failure, :not_enough_args}
+  def validate([_ | _] = args, _opts) when length(args) > 1, do: {:validation_failure, :too_many_args}
+
+  def validate([""], _opts),
     do: {:validation_failure, {:bad_argument, "feature_flag cannot be an empty string."}}
 
-  def validate([_], _), do: :ok
+  def validate([_], _opts), do: :ok
 
   use RabbitMQ.CLI.Core.RequiresRabbitAppRunning
 
@@ -29,32 +32,43 @@ defmodule RabbitMQ.CLI.Ctl.Commands.EnableFeatureFlagCommand do
     end
   end
 
-  def run([feature_flag], %{node: node_name}) do
-    case :rabbit_misc.rpc_call(node_name, :rabbit_feature_flags, :enable, [
-           String.to_atom(feature_flag)
-         ]) do
-      # Server does not support feature flags, consider none are available.
-      # See rabbitmq/rabbitmq-cli#344 for context. MK.
-      {:badrpc, {:EXIT, {:undef, _}}} -> {:error, :unsupported}
-      {:badrpc, _} = err -> err
-      other -> other
+  def run([feature_flag], %{node: node_name, force: force}) do
+    case {force, :rabbit_misc.rpc_call(node_name, :rabbit_feature_flags, :get_stability, [
+      String.to_atom(feature_flag)
+    ])} do
+      {false, :experimental} ->
+        IO.puts("Feature flag #{feature_flag} is experimental and requires --force to enable it.")
+      _ ->
+        case :rabbit_misc.rpc_call(node_name, :rabbit_feature_flags, :enable, [
+          String.to_atom(feature_flag)
+        ]) do
+          # Server does not support feature flags, consider none are available.
+          # See rabbitmq/rabbitmq-cli#344 for context. MK.
+          {:badrpc, {:EXIT, {:undef, _}}} -> {:error, :unsupported}
+          {:badrpc, _} = err -> err
+          other -> other
+        end
     end
   end
 
   def output({:error, :unsupported}, %{node: node_name}) do
     {:error, RabbitMQ.CLI.Core.ExitCodes.exit_usage(),
-     "This feature flag is not supported by node #{node_name}"}
+      "This feature flag is not supported by node #{node_name}"}
   end
 
   use RabbitMQ.CLI.DefaultOutput
 
-  def usage, do: "enable_feature_flag <all | feature_flag>"
+  def usage, do: "enable_feature_flag [--force] <all | feature_flag>"
 
   def usage_additional() do
     [
       [
         "<feature_flag>",
         "name of the feature flag to enable, or \"all\" to enable all supported flags"
+      ],
+      [
+        "--force",
+        "required to enable experimental feature flags (make sure you understand the risks!))"
       ]
     ]
   end