Set KAMAL_DESTINATION before rendering the config for an alias

lib/kamal/configuration.rb

@@ -18,14 +18,14 @@ class Kamal::Configuration
 
   class << self
     def create_from(config_file:, destination: nil, version: nil)
-      ENV["KAMAL_DESTINATION"] = destination
-
       raw_config = load_raw_config(config_file: config_file, destination: destination)
 
       new raw_config, destination: destination, version: version
     end
 
     def load_raw_config(config_file:, destination: nil)
+      ENV["KAMAL_DESTINATION"] = destination
+
       load_config_files(config_file, *destination_config_file(config_file, destination))
     end
 

test/cli/main_test.rb

@@ -808,6 +808,14 @@ class CliMainTest < CliTestCase
     end
   end
 
+  test "render an alias with the destination" do
+    ENV.delete("KAMAL_DESTINATION")
+
+    run_command("console", "-d", "world", config_file: "deploy_with_destination_aliases").tap do |output|
+      assert_match "bin/console world", output
+    end
+  end
+
   test "upgrade" do
     invoke_options = base_invoke_options(config_file: "deploy_with_accessories.yml", version: nil, confirmed: true, rolling: false)
     Kamal::Cli::Main.any_instance.expects(:invoke).with("kamal:cli:proxy:upgrade", [], invoke_options)

test/fixtures/deploy_with_destination_aliases.world.yml

@@ -0,0 +1,2 @@
+servers:
+  - 1.1.1.1

test/fixtures/deploy_with_destination_aliases.yml

@@ -0,0 +1,9 @@
+service: app
+image: dhh/app
+registry:
+  username: user
+  password: pw
+builder:
+  arch: amd64
+aliases:
+  console: app exec --reuse "bin/console <%= ENV["KAMAL_DESTINATION"] %>"