custom run launcher for custom docker image

system/run_launcher.py

@@ -0,0 +1,44 @@
+import structlog
+from dagster_docker import DockerRunLauncher
+
+import dagster._check as check
+from dagster._core.launcher.base import (
+    LaunchRunContext,
+)
+from dagster._grpc.types import ExecuteRunArgs
+
+logger = structlog.get_logger(__name__)
+
+
+class CustomDockerRunLauncher(DockerRunLauncher):
+    """
+    Custom Docker Run Launcher.
+
+    This class is an extension of the DockerRunLauncher, allowing for a custom Docker image
+    to be specified via the run tags. It overrides the `launch_run` method to accommodate
+    the custom image logic. If no custom image is provided in the tags, it defaults to
+    the behavior of the parent class. It also generates command arguments for the execution
+    container and launches the container with these arguments.
+    """
+
+    def launch_run(self, context: LaunchRunContext) -> None:
+        """
+        Launches a run in a Docker container with the specified command and image.
+
+        This function retrieves the Docker image from the run tags or determines it based on the
+        given job code origin. It then constructs the command to execute the run and launches
+        a Docker container to perform the execution.
+        """
+
+        run = context.dagster_run
+        job_code_origin = check.not_none(context.job_code_origin)
+        if not (docker_image := context.dagster_run.tags.get("docker/image")):
+            docker_image = self._get_docker_image(job_code_origin)
+
+        command = ExecuteRunArgs(
+            job_origin=job_code_origin,
+            run_id=run.run_id,
+            instance_ref=self._instance.get_ref(),
+        ).get_command_args()
+
+        self._launch_container_with_command(run, docker_image, command)