Add launch commands (#18155)

* Add launcher to main repo

* Move launcher CLI to main CLI

* Launch CLI tests

* Fix tests

* Remove tabulate dependency

* Allow access through lightning_app package

* Avoid conditional import in CLI

* Apply suggestions from code review

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Remove conditional input

* Skip mypy checks for launcher

* Add return type annotation

* Fix duplicated app_metadata.py

* Add missing import

* Fix test

* Add skip test import depth

* Remove leftover conditional import

* Change expected output to reflect the new tabulate method

* Remove check on deprecated functionality

* Improve stability of test

* Skip unrelated failing test on Windows

---------

Co-authored-by: Jirka Borovec <6035284+Borda@users.noreply.github.com>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

pyproject.toml

@@ -141,6 +141,7 @@ exclude = [
     "src/lightning/app/cli/component-template",
     "src/lightning/app/cli/pl-app-template",
     "src/lightning/app/cli/react-ui-template",
+    "src/lightning/app/launcher",
 ]
 install_types = "True"
 non_interactive = "True"

src/lightning/app/cli/lightning_cli.py

@@ -39,6 +39,7 @@
 )
 from lightning.app.cli.connect.data import connect_data
 from lightning.app.cli.lightning_cli_delete import delete
+from lightning.app.cli.lightning_cli_launch import launch
 from lightning.app.cli.lightning_cli_list import get_list
 from lightning.app.core.constants import ENABLE_APP_COMMENT_COMMAND_EXECUTION, get_lightning_cloud_url
 from lightning.app.runners.cloud import CloudRuntime
@@ -324,6 +325,7 @@ def open(path: str, name: str) -> None:
 
 _main.add_command(get_list)
 _main.add_command(delete)
+_main.add_command(launch)
 _main.add_command(cmd_install.install)
 
 

src/lightning/app/cli/lightning_cli_launch.py

@@ -0,0 +1,127 @@
+# Copyright The Lightning AI team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import logging
+from typing import Tuple
+
+import click
+
+from lightning.app.core.constants import APP_SERVER_HOST, APP_SERVER_PORT
+from lightning.app.launcher.launcher import (
+    run_lightning_flow,
+    run_lightning_work,
+    serve_frontend,
+    start_application_server,
+    start_flow_and_servers,
+)
+
+logger = logging.getLogger(__name__)
+
+
+@click.group(name="launch", hidden=True)
+def launch() -> None:
+    """Launch your application."""
+
+
+@launch.command("server", hidden=True)
+@click.argument("file", type=click.Path(exists=True))
+@click.option("--queue-id", help="ID for identifying queue", default="", type=str)
+@click.option("--host", help="Application running host", default=APP_SERVER_HOST, type=str)
+@click.option("--port", help="Application running port", default=APP_SERVER_PORT, type=int)
+def run_server(file: str, queue_id: str, host: str, port: int) -> None:
+    """It takes the application file as input, build the application object and then use that to run the
+    application server.
+
+    This is used by the cloud runners to start the status server for the application
+    """
+    logger.debug(f"Run Server: {file} {queue_id} {host} {port}")
+    start_application_server(file, host, port, queue_id=queue_id)
+
+
+@launch.command("flow", hidden=True)
+@click.argument("file", type=click.Path(exists=True))
+@click.option("--queue-id", help="ID for identifying queue", default="", type=str)
+@click.option("--base-url", help="Base url at which the app server is hosted", default="")
+def run_flow(file: str, queue_id: str, base_url: str) -> None:
+    """It takes the application file as input, build the application object, proxy all the work components and then
+    run the application flow defined in the root component.
+
+    It does exactly what a singleprocess dispatcher would do but with proxied work components.
+    """
+    logger.debug(f"Run Flow: {file} {queue_id} {base_url}")
+    run_lightning_flow(file, queue_id=queue_id, base_url=base_url)
+
+
+@launch.command("work", hidden=True)
+@click.argument("file", type=click.Path(exists=True))
+@click.option("--work-name", type=str)
+@click.option("--queue-id", help="ID for identifying queue", default="", type=str)
+def run_work(file: str, work_name: str, queue_id: str) -> None:
+    """Unlike other entrypoints, this command will take the file path or module details for a work component and
+    run that by fetching the states from the queues."""
+    logger.debug(f"Run Work: {file} {work_name} {queue_id}")
+    run_lightning_work(
+        file=file,
+        work_name=work_name,
+        queue_id=queue_id,
+    )
+
+
+@launch.command("frontend", hidden=True)
+@click.argument("file", type=click.Path(exists=True))
+@click.option("--flow-name")
+@click.option("--host")
+@click.option("--port", type=int)
+def run_frontend(file: str, flow_name: str, host: str, port: int) -> None:
+    """Serve the frontend specified by the given flow."""
+    logger.debug(f"Run Frontend: {file} {flow_name} {host}")
+    serve_frontend(file=file, flow_name=flow_name, host=host, port=port)
+
+
+@launch.command("flow-and-servers", hidden=True)
+@click.argument("file", type=click.Path(exists=True))
+@click.option("--queue-id", help="ID for identifying queue", default="", type=str)
+@click.option("--base-url", help="Base url at which the app server is hosted", default="")
+@click.option("--host", help="Application running host", default=APP_SERVER_HOST, type=str)
+@click.option("--port", help="Application running port", default=APP_SERVER_PORT, type=int)
+@click.option(
+    "--flow-port",
+    help="Pair of flow name and frontend port",
+    type=(str, int),
+    multiple=True,
+)
+def run_flow_and_servers(
+    file: str,
+    base_url: str,
+    queue_id: str,
+    host: str,
+    port: int,
+    flow_port: Tuple[Tuple[str, int]],
+) -> None:
+    """It takes the application file as input, build the application object and then use that to run the
+    application flow defined in the root component, the application server and all the flow frontends.
+
+    This is used by the cloud runners to start the flow, the status server and all frontends for the application
+    """
+    logger.debug(f"Run Flow: {file} {queue_id} {base_url}")
+    logger.debug(f"Run Server: {file} {queue_id} {host} {port}.")
+    logger.debug(f"Run Frontend's: {flow_port}")
+    start_flow_and_servers(
+        entrypoint_file=file,
+        base_url=base_url,
+        queue_id=queue_id,
+        host=host,
+        port=port,
+        flow_names_and_ports=flow_port,
+    )