Name the subcommand for hooks and output logs run through Main

lib/kamal/cli/base.rb

@@ -280,7 +280,12 @@ def command
       def subcommand
         @kamal_subcommand ||= begin
           invocation_class, invocation_commands = *first_invocation
-          invocation_commands[0] if invocation_class != Kamal::Cli::Main
+          if invocation_class != Kamal::Cli::Main
+            invocation_commands[0]
+          elsif subcommand_class = Kamal::Cli::Main.subcommand_classes[invocation_commands[0]]
+            # `kamal app boot` records Main's `app` first, then App's `boot`
+            instance_variable_get("@_invocations").fetch(subcommand_class, []).first
+          end
         end
       end
 

test/cli/app_test.rb

@@ -10,6 +10,29 @@ class CliAppTest < CliTestCase
     end
   end
 
+  test "boot through main names the subcommand to hooks and the output loggers" do
+    stub_running
+    Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
+
+    hook_env = {}
+    SSHKit::Backend::Abstract.any_instance.stubs(:execute).with do |*args|
+      hook_env[args.first] = ENV.slice("KAMAL_COMMAND", "KAMAL_SUBCOMMAND") if args.first.to_s.start_with?(".kamal/hooks/")
+      true
+    end
+
+    modifications = []
+    subscriber = ActiveSupport::Notifications.subscribe("modify.kamal") do |*, payload|
+      modifications << payload.slice(:command, :subcommand)
+    end
+
+    stdouted { Kamal::Cli::Main.start([ "app", "boot", "-c", "test/fixtures/deploy_with_accessories.yml", "--hosts", "1.1.1.1" ]) }
+
+    assert_equal({ "KAMAL_COMMAND" => "app", "KAMAL_SUBCOMMAND" => "boot" }, hook_env[".kamal/hooks/pre-app-boot"])
+    assert_equal [ { command: "app", subcommand: "boot" } ], modifications
+  ensure
+    ActiveSupport::Notifications.unsubscribe(subscriber) if subscriber
+  end
+
   test "boot will rename if same version is already running" do
     Object.any_instance.stubs(:sleep)
     run_command("details") # Preheat Kamal const