Tag image after booting and include destination

If you are deploying more than one destination to a host, the latest
tags will conflict, so we'll append the destination to the tag.

The latest tag is used when booting the app or exec-ing a new container.

If a deploy doesn't complete on a host for all roles then we should
probably not be using it, so move the tagging to the end of the boot
process.

lib/kamal/cli/app.rb

@@ -9,9 +9,6 @@ class Kamal::Cli::App < Kamal::Cli::Base
 
           # Assets are prepared in a separate step to ensure they are on all hosts before booting
           on(KAMAL.hosts) do
-            execute *KAMAL.auditor.record("Tagging #{KAMAL.config.absolute_image} as the latest image"), verbosity: :debug
-            execute *KAMAL.app.tag_current_image_as_latest
-
             KAMAL.roles_on(host).each do |role|
               Kamal::Cli::App::PrepareAssets.new(host, role, self).run
             end
@@ -21,6 +18,9 @@ class Kamal::Cli::App < Kamal::Cli::Base
             KAMAL.roles_on(host).each do |role|
               Kamal::Cli::App::Boot.new(host, role, version, self).run
             end
+
+            execute *KAMAL.auditor.record("Tagging #{KAMAL.config.absolute_image} as the latest image"), verbosity: :debug
+            execute *KAMAL.app.tag_latest_image
           end
         end
       end

lib/kamal/commands/app/assets.rb

@@ -5,7 +5,7 @@ module Kamal::Commands::App::Assets
     combine \
       make_directory(role.asset_extracted_path),
       [ *docker(:stop, "-t 1", asset_container, "2> /dev/null"), "|| true" ],
-      docker(:run, "--name", asset_container, "--detach", "--rm", config.latest_image, "sleep 1000000"),
+      docker(:run, "--name", asset_container, "--detach", "--rm", config.absolute_image, "sleep 1000000"),
       docker(:cp, "-L", "#{asset_container}:#{role.asset_path}/.", role.asset_extracted_path),
       docker(:stop, "-t 1", asset_container),
       by: "&&"

lib/kamal/commands/app/images.rb

@@ -7,7 +7,7 @@ module Kamal::Commands::App::Images
     docker :image, :prune, "--all", "--force", *filter_args
   end
 
-  def tag_current_image_as_latest
+  def tag_latest_image
     docker :tag, config.absolute_image, config.latest_image
   end
 end

lib/kamal/configuration.rb

@@ -128,7 +128,7 @@ class Kamal::Configuration
   end
 
   def latest_image
-    "#{repository}:latest"
+    "#{repository}:#{[ "latest", *destination ].join("-")}"
   end
 
   def service_with_version

test/commands/app_test.rb

@@ -339,12 +339,6 @@ class CommandsAppTest < ActiveSupport::TestCase
       new_command.remove_images.join(" ")
   end
 
-  test "tag_current_image_as_latest" do
-    assert_equal \
-      "docker tag dhh/app:999 dhh/app:latest",
-      new_command.tag_current_image_as_latest.join(" ")
-  end
-
   test "make_env_directory" do
     assert_equal "mkdir -p .kamal/env/roles", new_command.make_env_directory.join(" ")
   end
@@ -371,7 +365,7 @@ class CommandsAppTest < ActiveSupport::TestCase
     assert_equal [
       :mkdir, "-p", ".kamal/assets/extracted/app-web-999", "&&",
       :docker, :stop, "-t 1", "app-web-assets", "2> /dev/null", "|| true", "&&",
-      :docker, :run, "--name", "app-web-assets", "--detach", "--rm", "dhh/app:latest", "sleep 1000000", "&&",
+      :docker, :run, "--name", "app-web-assets", "--detach", "--rm", "dhh/app:999", "sleep 1000000", "&&",
       :docker, :cp, "-L", "app-web-assets:/public/assets/.", ".kamal/assets/extracted/app-web-999", "&&",
       :docker, :stop, "-t 1", "app-web-assets"
     ], new_command(asset_path: "/public/assets").extract_assets