cli: add first-party launchd install/uninstall commands for autostart

Introduce built-in launchd management to remove shell-wrapper indirection and
make macOS autostart reliable.

- Add `install-launchagent` and `uninstall-launchagent` CLI subcommands.
- Create launchd helper module to:
  - write `~/Library/LaunchAgents/<label>.plist`
  - invoke app via `sys.executable -m mpd_now_playable.cli` (absolute interpreter path)
  - set `RunAtLoad`, `KeepAlive`
  - run `launchctl bootout/bootstrap/kickstart` for install and `bootout` for uninstall
  - support `--label` and `--force`
- Add tests for subcommand dispatch, plist generation, and launchctl flow.
- Document the new launchd workflow in README.
  - Run markdownlint

This keeps the setup DRY/KISS, avoids PATH/shell expansion pitfalls in launchd,
and gives users a supported and easy autostart path out of the box.

README.md

@@ -1,11 +1,24 @@
-# mpd-now-playable [![PyPI version](https://badge.fury.io/py/mpd-now-playable.svg)](https://badge.fury.io/py/mpd-now-playable)
+# mpd-now-playable
 
-This little Python program turns your MPD server into a [now playable app](https://developer.apple.com/documentation/mediaplayer/becoming_a_now_playable_app) on MacOS.
+[![PyPI version](https://badge.fury.io/py/mpd-now-playable.svg)](https://badge.fury.io/py/mpd-now-playable)
+
+This little Python program turns your MPD server into a [now playable app](https://developer.apple.com/documentation/mediaplayer/becoming_a_now_playable_app) on macOS.
 This enables your keyboard's standard media keys to control MPD, as well as more esoteric music control methods like the buttons on your Bluetooth headphones.
 
+## Table of Contents
+
+<!-- toc -->
+
+- [Installation](#installation)
+- [Configuration](#configuration)
+- [Limitations](#limitations)
+
+<!-- tocstop -->
+
 ## Installation
 
 The recommended way to install mpd-now-playable and its dependencies is with [pipx](https://pypa.github.io/pipx/):
+
 ```shell
 pipx install mpd-now-playable
 # or, if you'd like to use a separate cache service, one of these:
@@ -15,7 +28,27 @@ pipx install mpd-now-playable[memcached]
 
 Once pipx is done, the `mpd-now-playable` script should be available on your `$PATH` and ready to use.
 
-Most likely, you'll want mpd-now-playable to stay running in the background as a launchd service. [Here's the service plist I use](https://git.00dani.me/00dani/mpd-now-playable/src/branch/main/me.00dani.mpd-now-playable.plist), but it's hardcoded to my `$HOME` so you'll want to customise it.
+Most likely, you'll want mpd-now-playable to stay running in the background as a `launchd` service. The CLI can install a per-user LaunchAgent for you:
+
+```shell
+mpd-now-playable install-launchagent
+```
+
+This writes `~/Library/LaunchAgents/me.00dani.mpd-now-playable.plist`, bootstraps it with `launchctl`, and starts it immediately.
+
+To replace an existing LaunchAgent plist:
+
+```shell
+mpd-now-playable install-launchagent --force
+```
+
+To remove it later:
+
+```shell
+mpd-now-playable uninstall-launchagent
+```
+
+You may override the launchd label in both commands with `--label`.
 
 ## Configuration
 
@@ -37,6 +70,7 @@ Additionally, mpd-now-playable caches your album artwork, by default simply in m
 You may provide a `namespace` query parameter to prefix cache keys if you wish, as well as a `password` query parameter if your service requires a password to access. As with your other environment variables, keep your cache password secure.
 
 One simple secure way to set your environment variables is with a small wrapper script like this:
+
 ```shell
 #!/bin/sh
 export MPD_HOSTNAME=my.cool.mpd.host
@@ -45,12 +79,15 @@ export MPD_PASSWORD=swordfish
 export MPD_NOW_PLAYABLE_CACHE='redis://localhost:6379/0?namespace=mpd-now-playable&password=fishsword'
 exec mpd-now-playable
 ```
+
 Make sure this wrapper script is only readable by you, with something like `chmod 700`!
 
+If you're using launchd, you can point `ProgramArguments` in your plist at that wrapper script instead.
+
 ## Limitations
 
-mpd-now-playable is currently *very* specific to MacOS. I did my best to keep the generic MPD and extremely Apple parts separate, but it definitely won't work with MPRIS2 or the Windows system media feature.
+mpd-now-playable is currently _very_ specific to macOS. I did my best to keep the generic MPD and extremely Apple parts separate, but it definitely won't work with MPRIS2 or the Windows system media feature.
 
-Chances are my MacOS integration code isn't the best, either. This is the first project I've written using PyObjC and it took a lot of fiddling to get working.
+Chances are my macOS integration code isn't the best, either. This is the first project I've written using PyObjC and it took a lot of fiddling to get working.
 
 I'm very open to contributions to fix any of these things, if you're interested in writing them!

me.00dani.mpd-now-playable.plist

@@ -1,16 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
-<plist version="1.0">
-<dict>
-	<key>KeepAlive</key>
-	<true/>
-	<key>Label</key>
-	<string>me.00dani.mpd-now-playable</string>
-	<key>ProgramArguments</key>
-	<array>
-		<string>/Users/dani/.local/bin/mpd-now-playable</string>
-	</array>
-	<key>RunAtLoad</key>
-	<true/>
-</dict>
-</plist>

src/mpd_now_playable/cli.py

@@ -1,3 +1,4 @@
+import argparse
 import asyncio
 import sys
 from collections.abc import Iterable
@@ -7,6 +8,7 @@ from rich import print as rich_print
 from .__version__ import __version__
 from .config.load import loadConfig
 from .config.model import Config
+from .launchd import DEFAULT_LABEL, install_launchagent, uninstall_launchagent
 from .mpd.listener import MpdStateListener
 from .song_receiver import (
 	Receiver,
@@ -24,20 +26,63 @@ async def listen(
 
 
 def print_help() -> None:
-	print("Usage: mpd-now-playable [OPTIONS]")
+	parser = build_parser()
-	print("")
+	parser.print_help()
-	print("Options:")
+
-	print("  -h, --help     Show this help message and exit.")
+
-	print("  -v, --version  Show version and exit.")
+def build_parser() -> argparse.ArgumentParser:
+	parser = argparse.ArgumentParser(prog="mpd-now-playable")
+	parser.add_argument(
+		"-v",
+		"--version",
+		action="store_true",
+		help="Show version and exit.",
+	)
+
+	subparsers = parser.add_subparsers(dest="command")
+	install_cmd = subparsers.add_parser(
+		"install-launchagent",
+		help="Install and start a per-user launchd service.",
+	)
+	install_cmd.add_argument(
+		"--label",
+		default=DEFAULT_LABEL,
+		help=f"launchd label to install (default: {DEFAULT_LABEL}).",
+	)
+	install_cmd.add_argument(
+		"--force",
+		action="store_true",
+		help="Replace an existing plist with the same label.",
+	)
+
+	uninstall_cmd = subparsers.add_parser(
+		"uninstall-launchagent",
+		help="Unload and remove a per-user launchd service.",
+	)
+	uninstall_cmd.add_argument(
+		"--label",
+		default=DEFAULT_LABEL,
+		help=f"launchd label to uninstall (default: {DEFAULT_LABEL}).",
+	)
+	return parser
 
 
 def main() -> None:
-	args = set(sys.argv[1:])
+	parser = build_parser()
-	if "-h" in args or "--help" in args:
+	args = parser.parse_args(sys.argv[1:])
-		print_help()
+
+	if args.version:
+		rich_print(f"mpd-now-playable v{__version__}")
 		return
-	if "-v" in args or "--version" in args:
+
-		print(f"mpd-now-playable v{__version__}")
+	if args.command == "install-launchagent":
+		path = install_launchagent(label=args.label, force=args.force)
+		rich_print(f"Installed LaunchAgent at {path}")
+		return
+
+	if args.command == "uninstall-launchagent":
+		path = uninstall_launchagent(label=args.label)
+		rich_print(f"Uninstalled LaunchAgent at {path}")
 		return
 
 	rich_print(f"mpd-now-playable v{__version__}")

src/mpd_now_playable/launchd.py

@@ -0,0 +1,85 @@
+import os
+import plistlib
+import subprocess
+import sys
+from pathlib import Path
+
+DEFAULT_LABEL = "me.00dani.mpd-now-playable"
+
+
+def _require_macos() -> None:
+	if sys.platform != "darwin":
+		msg = "launchd commands are only supported on macOS"
+		raise RuntimeError(msg)
+
+
+def _launch_agents_dir() -> Path:
+	return Path.home() / "Library" / "LaunchAgents"
+
+
+def plist_path_for_label(label: str) -> Path:
+	return _launch_agents_dir() / f"{label}.plist"
+
+
+def _service_target(label: str) -> str:
+	return f"gui/{os.getuid()}/{label}"
+
+
+def _launchctl_binary() -> str:
+	# Prefer absolute paths to avoid relying on PATH for privileged process control.
+	for candidate in ("/bin/launchctl", "/usr/bin/launchctl"):
+		if Path(candidate).exists():
+			return candidate
+	return "launchctl"
+
+
+def _run_launchctl(*args: str, check: bool = True) -> subprocess.CompletedProcess[str]:
+	return subprocess.run(  # noqa: S603 - arguments are fixed command tokens, shell is not used.
+		[_launchctl_binary(), *args],
+		check=check,
+		capture_output=True,
+		text=True,
+	)
+
+
+def _plist_bytes(label: str) -> bytes:
+	payload = {
+		"Label": label,
+		"ProgramArguments": [sys.executable, "-m", "mpd_now_playable.cli"],
+		"RunAtLoad": True,
+		"KeepAlive": True,
+	}
+	return plistlib.dumps(payload, fmt=plistlib.FMT_XML)
+
+
+def install_launchagent(label: str = DEFAULT_LABEL, force: bool = False) -> Path:
+	_require_macos()
+	plist_path = plist_path_for_label(label)
+	plist_path.parent.mkdir(parents=True, exist_ok=True)
+
+	if plist_path.exists() and not force:
+		msg = f"{plist_path} already exists; rerun with --force to replace it"
+		raise FileExistsError(msg)
+
+	plist_path.write_bytes(_plist_bytes(label))
+	target = _service_target(label)
+
+	# Ignore errors if the service does not already exist.
+	_run_launchctl("bootout", target, check=False)
+	_run_launchctl("bootstrap", f"gui/{os.getuid()}", str(plist_path))
+	_run_launchctl("kickstart", "-k", target)
+
+	return plist_path
+
+
+def uninstall_launchagent(label: str = DEFAULT_LABEL) -> Path:
+	_require_macos()
+	plist_path = plist_path_for_label(label)
+	target = _service_target(label)
+
+	# Ignore errors if the service is not loaded.
+	_run_launchctl("bootout", target, check=False)
+	if plist_path.exists():
+		plist_path.unlink()
+
+	return plist_path

tests/test_cli.py

@@ -1,5 +1,7 @@
 from types import SimpleNamespace
 
+import pytest
+
 import mpd_now_playable.cli as cli
 
 
@@ -11,12 +13,15 @@ def test_main_help_prints_usage(monkeypatch, capsys) -> None:
 
 	monkeypatch.setattr(cli, "loadConfig", fail_load)
 
-	cli.main()
+	with pytest.raises(SystemExit) as exc:
+		cli.main()
+	assert exc.value.code == 0
 	output = capsys.readouterr().out
 
-	assert "Usage: mpd-now-playable [OPTIONS]" in output
+	assert "usage: mpd-now-playable" in output
-	assert "-h, --help" in output
+	assert "--version" in output
-	assert "-v, --version" in output
+	assert "install-launchagent" in output
+	assert "uninstall-launchagent" in output
 
 
 def test_main_version_prints_version(monkeypatch, capsys) -> None:
@@ -93,3 +98,43 @@ def test_main_starts_listener_and_receivers(monkeypatch) -> None:
 	assert seen["receivers"] == (receiver_1, receiver_2)
 	assert seen["listen_args"] == (config, listener, (receiver_1, receiver_2))
 	assert seen["run"] == (fake_coroutine, FakeLoopFactory.make_loop, False)
+
+
+def test_main_install_launchagent(monkeypatch, capsys) -> None:
+	seen = {}
+
+	def fake_install(*, label: str, force: bool) -> str:
+		seen["args"] = (label, force)
+		return "/tmp/example.plist"
+
+	monkeypatch.setattr(
+		cli.sys,
+		"argv",
+		["mpd-now-playable", "install-launchagent", "--label", "com.example.test", "--force"],
+	)
+	monkeypatch.setattr(cli, "install_launchagent", fake_install)
+
+	cli.main()
+	output = capsys.readouterr().out
+	assert seen["args"] == ("com.example.test", True)
+	assert "Installed LaunchAgent at /tmp/example.plist" in output
+
+
+def test_main_uninstall_launchagent(monkeypatch, capsys) -> None:
+	seen = {}
+
+	def fake_uninstall(*, label: str) -> str:
+		seen["label"] = label
+		return "/tmp/example.plist"
+
+	monkeypatch.setattr(
+		cli.sys,
+		"argv",
+		["mpd-now-playable", "uninstall-launchagent", "--label", "com.example.test"],
+	)
+	monkeypatch.setattr(cli, "uninstall_launchagent", fake_uninstall)
+
+	cli.main()
+	output = capsys.readouterr().out
+	assert seen["label"] == "com.example.test"
+	assert "Uninstalled LaunchAgent at /tmp/example.plist" in output

tests/test_launchd.py

@@ -0,0 +1,77 @@
+import plistlib
+from pathlib import Path
+
+import pytest
+
+import mpd_now_playable.launchd as launchd
+
+
+def test_plist_bytes_uses_absolute_python(monkeypatch, tmp_path) -> None:
+	monkeypatch.setattr(launchd.sys, "executable", "/abs/python")
+	monkeypatch.setattr(Path, "home", lambda: tmp_path)
+
+	payload = plistlib.loads(launchd._plist_bytes("com.example.test"))
+
+	assert payload["Label"] == "com.example.test"
+	assert payload["ProgramArguments"] == ["/abs/python", "-m", "mpd_now_playable.cli"]
+	assert payload["RunAtLoad"] is True
+	assert payload["KeepAlive"] is True
+
+
+def test_install_launchagent_writes_plist_and_bootstraps(monkeypatch, tmp_path) -> None:
+	monkeypatch.setattr(launchd.sys, "platform", "darwin")
+	monkeypatch.setattr(launchd.sys, "executable", "/abs/python")
+	monkeypatch.setattr(Path, "home", lambda: tmp_path)
+	monkeypatch.setattr(launchd.os, "getuid", lambda: 501)
+
+	seen: list[tuple[tuple[str, ...], bool]] = []
+
+	def fake_run_launchctl(*args: str, check: bool = True) -> object:
+		seen.append((args, check))
+		return object()
+
+	monkeypatch.setattr(launchd, "_run_launchctl", fake_run_launchctl)
+
+	plist_path = launchd.install_launchagent(label="com.example.test", force=False)
+	assert plist_path == tmp_path / "Library" / "LaunchAgents" / "com.example.test.plist"
+	assert plist_path.exists()
+	assert seen == [
+		(("bootout", "gui/501/com.example.test"), False),
+		(("bootstrap", "gui/501", str(plist_path)), True),
+		(("kickstart", "-k", "gui/501/com.example.test"), True),
+	]
+
+
+def test_install_launchagent_refuses_existing_without_force(monkeypatch, tmp_path) -> None:
+	monkeypatch.setattr(launchd.sys, "platform", "darwin")
+	monkeypatch.setattr(Path, "home", lambda: tmp_path)
+
+	plist = tmp_path / "Library" / "LaunchAgents" / "com.example.test.plist"
+	plist.parent.mkdir(parents=True, exist_ok=True)
+	plist.write_text("already here")
+
+	with pytest.raises(FileExistsError):
+		launchd.install_launchagent(label="com.example.test")
+
+
+def test_uninstall_launchagent_boots_out_and_removes_file(monkeypatch, tmp_path) -> None:
+	monkeypatch.setattr(launchd.sys, "platform", "darwin")
+	monkeypatch.setattr(Path, "home", lambda: tmp_path)
+	monkeypatch.setattr(launchd.os, "getuid", lambda: 501)
+
+	seen: list[tuple[tuple[str, ...], bool]] = []
+
+	def fake_run_launchctl(*args: str, check: bool = True) -> object:
+		seen.append((args, check))
+		return object()
+
+	monkeypatch.setattr(launchd, "_run_launchctl", fake_run_launchctl)
+
+	plist = tmp_path / "Library" / "LaunchAgents" / "com.example.test.plist"
+	plist.parent.mkdir(parents=True, exist_ok=True)
+	plist.write_text("x")
+
+	removed = launchd.uninstall_launchagent(label="com.example.test")
+	assert removed == plist
+	assert not plist.exists()
+	assert seen == [(("bootout", "gui/501/com.example.test"), False)]