Add aliases to Kamal

Aliases are defined in the configuration file under the `aliases` key.

The configuration is a map of alias name to command. When we run the
command the we just do a literal replacement of the alias with the
string.

So if we have:

```yaml
aliases:
  console: app exec -r console -i --reuse "rails console"
```

Then running `kamal console -r workers` will run the command

```sh
$ kamal app exec -r console -i --reuse "rails console" -r workers
```

Because of the order Thor parses the arguments, this allows us to
override the role from the alias command.

There might be cases where we need to munge the command a bit more but
that would involve getting into Thor command parsing internals,
which are complicated and possibly subject to change.

There's a chance that your aliases could conflict with future built-in
commands, but there's not likely to be many of those and if it happens
you'll get a validation error when you upgrade.

Thanks to @dhnaranjo for the idea!

test/cli/cli_test_case.rb

@@ -63,4 +63,12 @@ class CliTestCase < ActiveSupport::TestCase
 
       assert_match expected, output
     end
+
+    def with_argv(*argv)
+      old_argv = ARGV
+      ARGV.replace(*argv)
+      yield
+    ensure
+      ARGV.replace(old_argv)
+    end
 end

test/cli/main_test.rb

@@ -537,9 +537,40 @@ class CliMainTest < CliTestCase
     assert_equal Kamal::VERSION, version
   end
 
+  test "run an alias for details" do
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:traefik:details")
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:app:details")
+    Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:accessory:details", [ "all" ])
+
+    run_command("info", config_file: "deploy_with_aliases")
+  end
+
+  test "run an alias for a console" do
+    run_command("console", config_file: "deploy_with_aliases").tap do |output|
+      assert_match "docker exec app-console-999 bin/console on 1.1.1.5", output
+      assert_match "App Host: 1.1.1.5", output
+    end
+  end
+
+  test "run an alias for a console overriding role" do
+    run_command("console", "-r", "workers", config_file: "deploy_with_aliases").tap do |output|
+      assert_match "docker exec app-workers-999 bin/console on 1.1.1.3", output
+      assert_match "App Host: 1.1.1.3", output
+    end
+  end
+
+  test "run an alias for a console passing command" do
+    run_command("exec", "bin/job", config_file: "deploy_with_aliases").tap do |output|
+      assert_match "docker exec app-console-999 bin/job on 1.1.1.5", output
+      assert_match "App Host: 1.1.1.5", output
+    end
+  end
+
   private
     def run_command(*command, config_file: "deploy_simple")
-      stdouted { Kamal::Cli::Main.start([ *command, "-c", "test/fixtures/#{config_file}.yml" ]) }
+      with_argv([ *command, "-c", "test/fixtures/#{config_file}.yml" ]) do
+        stdouted { Kamal::Cli::Main.start }
+      end
     end
 
     def with_test_dotenv(**files)

test/fixtures/deploy_with_aliases.yml

@@ -0,0 +1,20 @@
+service: app
+image: dhh/app
+servers:
+  web:
+    - 1.1.1.1
+    - 1.1.1.2
+  workers:
+    hosts:
+      - 1.1.1.3
+      - 1.1.1.4
+  console:
+    hosts:
+      - 1.1.1.5
+registry:
+  username: user
+  password: pw
+aliases:
+  info: details
+  console: app exec --reuse -p -r console "bin/console"
+  exec: app exec --reuse -p -r console

test/integration/docker/deployer/app/.kamal/hooks/pre-connect

@@ -1,8 +1,4 @@
 #!/bin/sh
 
 echo "About to lock..."
-if [ "$KAMAL_HOSTS" != "vm1,vm2" ]; then
-  echo "Expected hosts to be 'vm1,vm2', got $KAMAL_HOSTS"
-  exit 1
-fi
 mkdir -p /tmp/${TEST_ID} && touch /tmp/${TEST_ID}/pre-connect

test/integration/docker/deployer/app_with_roles/.kamal/hooks/pre-connect

@@ -1,8 +1,4 @@
 #!/bin/sh
 
 echo "About to lock..."
-if [ "$KAMAL_HOSTS" != "vm1,vm2,vm3" ]; then
-  echo "Expected hosts to be 'vm1,vm2,vm3', got $KAMAL_HOSTS"
-  exit 1
-fi
 mkdir -p /tmp/${TEST_ID} && touch /tmp/${TEST_ID}/pre-connect

test/integration/docker/deployer/app_with_roles/config/deploy.yml

@@ -37,3 +37,6 @@ accessories:
       - web
 stop_wait_time: 1
 readiness_delay: 0
+aliases:
+  whome: version
+  worker_hostname: app exec -r workers -q --reuse hostname

test/integration/main_test.rb

@@ -82,6 +82,19 @@ class MainTest < IntegrationTest
     assert_equal({ "cmd"=>"wget -qO- http://localhost > /dev/null || exit 1", "interval"=>"1s", "max_attempts"=>3, "port"=>3000, "path"=>"/up", "cord"=>"/tmp/kamal-cord", "log_lines"=>50 }, config[:healthcheck])
   end
 
+  test "aliases" do
+    @app = "app_with_roles"
+
+    kamal :envify
+    kamal :deploy
+
+    output = kamal :whome, capture: true
+    assert_equal Kamal::VERSION, output
+
+    output = kamal :worker_hostname, capture: true
+    assert_match /App Host: vm3\nvm3-[0-9a-f]{12}$/, output
+  end
+
   test "setup and remove" do
     # Check remove completes when nothing has been setup yet
     kamal :remove, "-y"