service: Support specifying container command

roles/service/meta/argument_specs.yaml

@@ -8,6 +8,13 @@ argument_specs:
         type: str
         required: true
 
+      service_container_command:
+        description: Command to start the service container with.
+        type: list
+        required: false
+        default: []
+        elements: str
+
       service_domains:
         description: A list of domains which should be proxied to the main service container
         type: list
@@ -242,8 +249,8 @@ argument_specs:
         description:
           - List of additional containers for the service.
           - >
-            Will inherit most options from main service container, except for publish_ports.
-            All options can be overridden per-container.
+            Will inherit most options from main service container. All options can be overridden
+            per-container.
         type: list
         required: false
         default: []
@@ -263,6 +270,12 @@ argument_specs:
             type: str
             required: false
             default: "{{ service_container_image }}"
+          command:
+            description: Command to start the container with.
+            type: list
+            required: false
+            default: "[]"
+            elements: str
           mounts:
             description: List of bind mounts or volumes to be mounted inside the main service container.
             type: list