Only use barrier when needed, more descriptive info

Author: djmb

lib/kamal/cli/app.rb

@@ -15,7 +15,7 @@ def boot
           end
 
           #  Primary hosts and roles are returned first, so they can open the barrier
-          barrier = Kamal::Cli::Healthcheck::Barrier.new
+          barrier = Kamal::Cli::Healthcheck::Barrier.new if KAMAL.roles.many?
 
           on(KAMAL.hosts, **KAMAL.boot_strategy) do |host|
             KAMAL.roles_on(host).each do |role|

lib/kamal/cli/app/boot.rb

@@ -43,8 +43,8 @@ def start_new_version
 
       reach_barrier
     rescue => e
-      if barrier_role? && barrier.close
-        info "Deploy failed, so closed barrier (#{host})"
+      if barrier_role? && barrier&.close
+        info "First #{KAMAL.primary_role} container unhealthy, stopping other roles (#{host})"
         error capture_with_info(*app.logs(version: version))
         error capture_with_info(*app.container_health_log(version: version))
       end
@@ -71,7 +71,7 @@ def reach_barrier
       if barrier
         if barrier_role?
           if barrier.open
-            info "Opened barrier (#{host})"
+            info "First #{KAMAL.primary_role} container healthy, continuing other roles (#{host})"
           end
         else
           wait_for_barrier
@@ -80,11 +80,11 @@ def reach_barrier
     end
 
     def wait_for_barrier
-      info "Waiting at web barrier (#{host})..."
+      info "Waiting for a healthy #{KAMAL.primary_role} container (#{host})..."
       barrier.wait
-      info "Barrier opened (#{host})"
+      info "First #{KAMAL.primary_role} container is healthy, continuing (#{host})"
     rescue Kamal::Cli::Healthcheck::Error
-      info "Barrier closed, shutting down new container (#{host})..."
+      info "First #{KAMAL.primary_role} container is unhealthy, stopping (#{host})"
       raise
     end
 

test/cli/app_test.rb

@@ -136,10 +136,10 @@ class CliAppTest < CliTestCase
       .returns("running").at_least_once # workers health check
 
     run_command("boot", config: :with_roles, host: nil).tap do |output|
-      assert_match "Waiting at web barrier (1.1.1.3)...", output
-      assert_match "Waiting at web barrier (1.1.1.4)...", output
-      assert_match "Barrier opened (1.1.1.3)", output
-      assert_match "Barrier opened (1.1.1.4)", output
+      assert_match "Waiting for a healthy web container (1.1.1.3)...", output
+      assert_match "Waiting for a healthy web container (1.1.1.4)...", output
+      assert_match "First web container is healthy, continuing (1.1.1.3)", output
+      assert_match "First web container is healthy, continuing (1.1.1.4)", output
     end
   end
 
@@ -160,10 +160,10 @@ class CliAppTest < CliTestCase
 
     stderred do
       run_command("boot", config: :with_roles, host: nil, allow_execute_error: true).tap do |output|
-        assert_match "Waiting at web barrier (1.1.1.3)...", output
-        assert_match "Waiting at web barrier (1.1.1.4)...", output
-        assert_match "Barrier closed, shutting down new container (1.1.1.3)...", output
-        assert_match "Barrier closed, shutting down new container (1.1.1.4)...", output
+        assert_match "Waiting for a healthy web container (1.1.1.3)...", output
+        assert_match "Waiting for a healthy web container (1.1.1.4)...", output
+        assert_match "First web container is unhealthy, stopping (1.1.1.3)", output
+        assert_match "First web container is unhealthy, stopping (1.1.1.4)", output
         assert_match "Running docker container ls --all --filter name=^app-web-latest$ --quiet | xargs docker stop on 1.1.1.1", output
         assert_match "Running docker container ls --all --filter name=^app-web-latest$ --quiet | xargs docker stop on 1.1.1.2", output
         assert_match "Running docker container ls --all --filter name=^app-workers-latest$ --quiet | xargs docker stop on 1.1.1.3", output

test/integration/broken_deploy_test.rb

@@ -25,9 +25,9 @@ class BrokenDeployTest < IntegrationTest
 
   private
     def assert_failed_deploy(output)
-      assert_match "Waiting at web barrier (vm3)...", output
-      assert_match /Deploy failed, so closed barrier \(vm[12]\)/, output
-      assert_match "Barrier closed, shutting down new container (vm3)...", output
+      assert_match "Waiting for a healthy web container (vm3)...", output
+      assert_match /First #{KAMAL.primary_role} container is unhealthy, stopping \(vm[12]\)/, output
+      assert_match "First #{KAMAL.primary_role} container unhealthy, stopping other roles (vm3)...", output
       assert_match "nginx: [emerg] unexpected end of file, expecting \";\" or \"}\" in /etc/nginx/conf.d/default.conf:2", output
       assert_match 'ERROR {"Status":"unhealthy","FailingStreak":0,"Log":[]}', output
     end