Add passthrough functionality to Docker image entrypoint

Author: codedmonkey

docker/entrypoint.sh

@@ -2,13 +2,18 @@
 
 set -e
 
-# If the first argument is `-init`, execute supervisor to run the
-# application, which is the default command, or pass the argument
-# to the Dirigent binary
+# If the first argument is `-init`, run the application. This is
+# also the default command.
 if [ "$1" = "-init" ]; then
   set -- /srv/init.sh
 else
-  set -- bin/dirigent "$@"
+  # If the first argument is `--`, execute the remaining arguments as a
+  # new command, otherwise pass the arguments to the Dirigent binary.
+  if [ "$1" = "--" ]; then
+    set -- ${@:2}
+  else
+    set -- bin/dirigent "$@"
+  fi
 fi
 
 exec "$@"

tests/Docker/Standalone/EntrypointTest.php

@@ -41,4 +41,18 @@ public function testDirigent(): void
 
         $this->assertStringStartsWith('Dirigent', $result, 'Running the container with any other command (than `-init`) must be passed to the Dirigent binary.');
     }
+
+    public function testPassthrough(): void
+    {
+        $container = (new GenericContainer('dirigent-standalone'))
+            ->withCommand(['--', 'bin/console', 'list'])
+            ->withWait(new WaitForLog('Symfony'))
+            ->start();
+
+        $result = $container->logs();
+
+        $container->stop();
+
+        $this->assertStringStartsWith(')Symfony', $result, 'Running the container with an `--` argument must have its remaining arguments be interpreted as a command.');
+    }
 }