From 04568dea2f4f252e43451497dace72cbea2dae9a Mon Sep 17 00:00:00 2001
From: Donal McBreen <donal@37signals.com>
Date: Tue, 22 Apr 2025 09:00:22 +0100
Subject: [PATCH] Inherit locks

We'll set the KAMAL_LOCK environment when calling run hooks. If set to
true we have the lock and the hook will not need to acquire it again if
it runs kamal commands.

Fixes: https://github.com/basecamp/kamal/issues/1517
---
 lib/kamal/cli/base.rb  |  8 +++++++-
 lib/kamal/commander.rb |  2 +-
 test/cli/main_test.rb  | 37 +++++++++++++++++++++++++++++++++++--
 3 files changed, 43 insertions(+), 4 deletions(-)

diff --git a/lib/kamal/cli/base.rb b/lib/kamal/cli/base.rb
index 7e5dd77b..9005e1c7 100644
--- a/lib/kamal/cli/base.rb
+++ b/lib/kamal/cli/base.rb
@@ -133,7 +133,13 @@ module Kamal::Cli
 
       def run_hook(hook, **extra_details)
         if !options[:skip_hooks] && KAMAL.hook.hook_exists?(hook)
-          details = { hosts: KAMAL.hosts.join(","), roles: KAMAL.specific_roles&.join(","), command: command, subcommand: subcommand }.compact
+          details = {
+            hosts: KAMAL.hosts.join(","),
+            roles: KAMAL.specific_roles&.join(","),
+            lock: KAMAL.holding_lock?.to_s,
+            command: command,
+            subcommand: subcommand
+          }.compact
 
           say "Running the #{hook} hook...", :magenta
           with_env KAMAL.hook.env(**details, **extra_details) do
diff --git a/lib/kamal/commander.rb b/lib/kamal/commander.rb
index 8a4356ed..0882311d 100644
--- a/lib/kamal/commander.rb
+++ b/lib/kamal/commander.rb
@@ -13,7 +13,7 @@ class Kamal::Commander
 
   def reset
     self.verbosity = :info
-    self.holding_lock = false
+    self.holding_lock = ENV["KAMAL_LOCK"] == "true"
     self.connected = false
     @specifics = @specific_roles = @specific_hosts = nil
     @config = @config_kwargs = nil
diff --git a/test/cli/main_test.rb b/test/cli/main_test.rb
index d37c9352..735fbd00 100644
--- a/test/cli/main_test.rb
+++ b/test/cli/main_test.rb
@@ -43,7 +43,7 @@ class CliMainTest < CliTestCase
     with_test_secrets("secrets" => "DB_PASSWORD=secret") do
       invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false, "verbose" => true }
 
-        Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
+      Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
       Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:proxy:boot", [], invoke_options)
       Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
       Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
@@ -53,7 +53,7 @@ class CliMainTest < CliTestCase
 
       run_command("deploy", "--verbose").tap do |output|
         assert_hook_ran "pre-connect", output
-          assert_match /Build and push app image/, output
+        assert_match /Build and push app image/, output
         assert_hook_ran "pre-deploy", output
         assert_match /Ensure kamal-proxy is running/, output
         assert_match /Detect stale containers/, output
@@ -116,6 +116,32 @@ class CliMainTest < CliTestCase
     end
   end
 
+  test "deploy when inheriting lock" do
+    Thread.report_on_exception = false
+
+    invoke_options = { "config_file" => "test/fixtures/deploy_simple.yml", "version" => "999", "skip_hooks" => false }
+
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:build:deliver", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:proxy:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:stale_containers", [], invoke_options.merge(stop: true))
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:boot", [], invoke_options)
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:prune:all", [], invoke_options)
+
+    Kamal::Commands::Hook.any_instance.stubs(:hook_exists?).returns(true)
+
+    with_kamal_lock_env do
+      KAMAL.reset
+      run_command("deploy").tap do |output|
+        assert_no_match /Acquiring the deploy lock/, output
+        assert_match /Build and push app image/, output
+        assert_match /Ensure kamal-proxy is running/, output
+        assert_match /Detect stale containers/, output
+        assert_match /Prune old containers and images/, output
+        assert_no_match /Releasing the deploy lock/, output
+      end
+    end
+  end
+
   test "deploy error when locking" do
     Thread.report_on_exception = false
 
@@ -562,4 +588,11 @@ class CliMainTest < CliTestCase
     def assert_file(file, content)
       assert_match content, File.read(file)
     end
+
+    def with_kamal_lock_env
+      ENV["KAMAL_LOCK"] = "true"
+      yield
+    ensure
+      ENV.delete("KAMAL_LOCK")
+    end
 end