mpd-now-playable/README.md
Danielle McLean 27d8c37139
Significantly overhaul configuration management
Everything now uses bog-standard Python dataclasses, with Pydantic
providing validation and type conversion through separate classes using
its type adapter feature. It's also possible to define your classes
using Pydantic's own model type directly, making the type adapter
unnecessary, but I didn't want to do things that way because no actual
validation is needed when constructing a Song instance for example.
Having Pydantic do its thing only on-demand was preferable.

I tried a number of validation libraries before settling on Pydantic for
this. It's not the fastest option out there (msgspec is I think), but it
makes adding support for third-party types like yarl.URL really easy, it
generates a nice clean JSON Schema which is easy enough to adjust to my
requirements through its GenerateJsonSchema hooks, and raw speed isn't
all that important anyway since this is a single-user desktop program
that reads its configuration file once on startup.

Also, MessagePack is now mandatory if you're caching to an external
service. It just didn't make a whole lot sense to explicitly install
mpd-now-playable's Redis or Memcached support and then use pickling with
them.

With all this fussing around done, I'm probably finally ready to
actually use that configuration file to configure new features! Yay!
2024-07-01 00:10:17 +10:00

4.1 KiB

mpd-now-playable PyPI version

This little Python program turns your MPD server into 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.

Installation

The recommended way to install mpd-now-playable and its dependencies is with pipx:

pipx install mpd-now-playable
# or, if you'd like to use a separate cache service, one of these:
pipx install mpd-now-playable[redis]
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, but it's hardcoded to my $HOME so you'll want to customise it.

Configuration

You may not need any configuration! If you've got a relatively normal MPD setup on your local machine, mpd-now-playable ought to just work out of the box, as it uses sensible defaults. If you need to control a remote MPD server, or your MPD clients use a password, though, you'll need configuration for that use case.

Currently, mpd-now-playable can only be configured through environment variables. Command-line arguments are intentionally not supported, since your MPD password is among the supported settings and command-line arguments are not a secure way to pass secrets such as passwords into commands. Reading configuration from a file is secure, provided the file itself is kept secure, so mpd-now-playable may support a config file in future.

The following environment variables are read. The MPD_HOST and MPD_PORT variables are supported in the same way mpc uses them, but you can alternatively provide your password as a separate MPD_PASSWORD variable if you wish.

  • MPD_HOST - defaults to localhost, which should be fine for most users. If you want to control a remote MPD server, though, you can.
  • MPD_PORT - defaults to 6600, which will almost always be the correct port to use.
  • MPD_PASSWORD - has no default. Set this only if your MPD server expects a password. You can also provide a password by setting MPD_HOST=password@host, if you want to be consistent with how mpc works.

Additionally, mpd-now-playable caches your album artwork, by default simply in memory. It may be configured to use an external cache, and currently supports Redis and Memcached for this purpose. To use one of these, set the environment variable MPD_NOW_PLAYABLE_CACHE to an appropriate URL for your cache service:

  • For Redis, use something like redis://localhost:6379/0.
  • For Memcached, use something like memcached://localhost:11211.

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:

#!/bin/sh
export MPD_HOSTNAME=my.cool.mpd.host
export MPD_PORT=6700
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!

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.

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!