From 8024949fe747fe3d4c12209ba971b98ca177a471 Mon Sep 17 00:00:00 2001
From: David Heinemeier Hansson <dhh@hey.com>
Date: Fri, 3 Feb 2023 13:20:03 +0100
Subject: [PATCH] Remove only specific container needed for rebooting

---
 lib/mrsk/cli/app.rb                      | 17 ++++++++++++-----
 lib/mrsk/commands/app.rb                 | 18 ++++++++++++++++--
 lib/mrsk/commands/concerns/repository.rb |  4 ++++
 test/cli/app_test.rb                     | 21 +++++++++++++++++----
 4 files changed, 49 insertions(+), 11 deletions(-)

diff --git a/lib/mrsk/cli/app.rb b/lib/mrsk/cli/app.rb
index 06fd552d..ba64535b 100644
--- a/lib/mrsk/cli/app.rb
+++ b/lib/mrsk/cli/app.rb
@@ -21,10 +21,12 @@ class Mrsk::Cli::App < Mrsk::Cli::Base
     end
   end
 
-  desc "reboot", "Reboot app on host (stop container, remove containers, start new container)"
+  desc "reboot", "Reboot app on host (stop container, remove container, start new container with latest image)"
   def reboot
+    old_version = current_running_version
+
     stop
-    remove_containers
+    remove_container old_version
     boot
   end
 
@@ -147,7 +149,12 @@ class Mrsk::Cli::App < Mrsk::Cli::Base
     remove_images
   end
 
-  desc "remove_containers", "Remove app containers from servers"
+  desc "remove_container [VERSION]", "Remove app container with given version from servers"
+  def remove_container(version)
+    on(MRSK.hosts) { execute *MRSK.app.remove_container(version: version) }
+  end
+
+  desc "remove_containers", "Remove all app containers from servers"
   def remove_containers
     on(MRSK.hosts) { execute *MRSK.app.remove_containers }
   end
@@ -184,9 +191,9 @@ class Mrsk::Cli::App < Mrsk::Cli::Base
       version
     end
 
-    def current_running_version(host:)
+    def current_running_version(host: MRSK.primary_host)
       version = nil
       on(host) { version = capture_with_info(*MRSK.app.current_running_version).strip }
-      version
+      version.presence
     end
 end
diff --git a/lib/mrsk/commands/app.rb b/lib/mrsk/commands/app.rb
index 237277fd..c95aa1e1 100644
--- a/lib/mrsk/commands/app.rb
+++ b/lib/mrsk/commands/app.rb
@@ -10,7 +10,7 @@ class Mrsk::Commands::App < Mrsk::Commands::Base
     docker :run,
       "-d",
       "--restart unless-stopped",
-      "--name", config.service_with_version,
+      "--name", service_with_version,
       *rails_master_key_arg,
       *role.env_args,
       *config.volume_args,
@@ -20,7 +20,7 @@ class Mrsk::Commands::App < Mrsk::Commands::Base
   end
 
   def start(version: config.version)
-    docker :start, "#{config.service}-#{version}"
+    docker :start, service_with_version(version)
   end
 
   def current_container_id
@@ -84,6 +84,12 @@ class Mrsk::Commands::App < Mrsk::Commands::Base
     docker :container, :ls, "-a", *service_filter
   end
 
+  def remove_container(version:)
+    pipe \
+      container_id_for(container_name: service_with_version(version)),
+      docker(:container, :rm)
+  end
+
   def remove_containers
     docker :container, :prune, "-f", *service_filter
   end
@@ -97,6 +103,14 @@ class Mrsk::Commands::App < Mrsk::Commands::Base
   end
 
   private
+    def service_with_version(version = nil)
+      if version
+        "#{config.service}-#{version}"
+      else
+        config.service_with_version
+      end
+    end
+
     def service_filter
       [ "--filter", "label=service=#{config.service}" ]
     end
diff --git a/lib/mrsk/commands/concerns/repository.rb b/lib/mrsk/commands/concerns/repository.rb
index 6e8a4f24..18a8f5fd 100644
--- a/lib/mrsk/commands/concerns/repository.rb
+++ b/lib/mrsk/commands/concerns/repository.rb
@@ -1,5 +1,9 @@
 module Mrsk::Commands::Concerns
   module Repository
+    def container_id_for(container_name:)
+      docker :container, :ls, "-a", "-f", "name=#{container_name}", "-q"
+    end
+
     def current_running_version
       # FIXME: Find more graceful way to extract the version from "app-version" than using sed and tail!
       pipe \
diff --git a/test/cli/app_test.rb b/test/cli/app_test.rb
index e63838ef..d3856c98 100644
--- a/test/cli/app_test.rb
+++ b/test/cli/app_test.rb
@@ -5,11 +5,24 @@ class CliAppTest < CliTestCase
     assert_match /Running docker run -d --restart unless-stopped/, run_command("boot")
   end
 
-  test "reboot" do
+  test "reboot to default version" do
     run_command("reboot").tap do |output|
-      assert_match /docker stop/, output
-      assert_match /docker container prune/, output
-      assert_match /docker run -d --restart unless-stopped/, output
+      assert_match /docker ps --filter label=service=app/, output # Find current container
+      assert_match /docker stop/, output # Stop old container
+      assert_match /docker container rm/, output # Remove old container
+      assert_match /docker run -d --restart unless-stopped .* dhh\/app:999/, output # Start new container
+    end
+  end
+
+  test "reboot to specific version" do
+    run_command("reboot", "--version", "456").tap do |output|
+      assert_match /docker run -d --restart unless-stopped .* dhh\/app:456/, output
+    end
+  end
+
+  test "remove_container" do
+    run_command("remove_container", "1234567").tap do |output|
+      assert_match /docker container ls -a -f name=app-1234567 -q | docker container rm/, output
     end
   end