Ensure that args/cmd arguments are passed to CP even without image

Author: jepetty

src/azure-cli/azure/cli/command_modules/containerapp/custom.py

@@ -1555,7 +1555,12 @@ def start_containerappsjob(cmd,
 
     template_def = None
 
-    if image is not None:
+    # Check if any container override parameters are provided
+    has_container_overrides = (image is not None or container_name is not None or
+                               env_vars is not None or startup_command is not None or
+                               args is not None or cpu is not None or memory is not None)
+
+    if has_container_overrides:
         template_def = JobExecutionTemplateModel
         container_def = ContainerModel
         resources_def = None
@@ -1565,7 +1570,25 @@ def start_containerappsjob(cmd,
             resources_def["memory"] = memory
 
         container_def["name"] = container_name if container_name else name
-        container_def["image"] = image if not is_registry_msi_system(registry_identity) else HELLO_WORLD_IMAGE
+
+        # If no image is provided, fetch the existing job's image
+        if image is not None:
+            container_def["image"] = image if not is_registry_msi_system(registry_identity) else HELLO_WORLD_IMAGE
+        else:
+            # Fetch the existing job definition to get the default image
+            try:
+                containerappjob_def = ContainerAppsJobClient.show(cmd=cmd, resource_group_name=resource_group_name, name=name)
+            except Exception as e:
+                handle_raw_exception(e)
+
+            if not containerappjob_def:
+                raise ResourceNotFoundError("The containerapp job '{}' does not exist".format(name))
+
+            existing_image = safe_get(containerappjob_def, "properties", "template", "containers", default=[{}])[0].get("image")
+            if not existing_image:
+                raise ValidationError("Could not find an existing image for the containerapp job '{}'. Please specify --image.".format(name))
+            container_def["image"] = existing_image
+
         if env_vars is not None:
             container_def["env"] = parse_env_var_flags(env_vars)
         if startup_command is not None: