This is a small Flask-based web application to allow on-demand updating of a Plex library, sending an email notification when new media has been added.

My Plex server runs on a Mac Mini, with the actual media held on a Synology NAS, neither of which is a computational powerhouse. Having Plex randomly initiate library update scans can quite negatively affect the server's performance, leading to playback issues if I happen to be watching something at the same time. In addition, as the media is stored on a network share, Plex cannot reliably identify when new media has been added. I have therefore disabled any of Plex's automatic library scanning and updating.

This has left me with the problem of how to get media properly added to Plex in a timely fashion (i.e. so that I don't have to manually run a scan). I wanted to have a way to get Plex to update the library on-demand when new media has been added. Since I receive an email from the NAS when a download has completed, I figured I could use procmail or something to ping a webservice and trigger the updating on demand.

Also, I wanted to play around with Flask!

The system has been implemented with the following setup in mind:

• Flask running under uWSGI behind nginx
• Redis as a simple key/value store to keep track of when updates have been performed, and which media has been added to the system
• Celery with RabbitMQ as an async task processor

1. Install Redis. By default, the system uses the following access URL: redis://localhost:6379/1.

2. Install RabbitMQ. By default, the system uses the following access URL: amqp://plexlib:plexlib@localhost/plexlib so if you want to use those values, you'll need to set up RabbitMQ appropriately.

   rabbitmqctl add_vhost plexlib
   rabbitmqctl add_user plexlib plexlib
   rabbitmqctl -p plexlib set_permissions plexlib '.*' '.*' '.*'
   

   Note: it's possible to use Redis as a broker instead of RabbitMQ, but as of this writing, Redis does not support broadcast tasks, which are used from Celerybeat to periodically check that Celery workers have access to the Plex video volume.

3. Create a virtualenv called plexlib, and use pip to install the requirements from requirements.txt

4. At the top of the project, create a directory named envs, and create the following files with the appropriate content. Alternatively, variables with these names can be specified directly in the environment for both Flask and Celery.

   • FLASK_ADMINS: a python list containing email addresses that should receive notifications in the event Flask throws an exception. Example: ['postmaster@yourdomain.com']
   • FLASK_CONFIG: (optional) set this to ProdConfig in a production environment.
   • FLASK_DEBUG: (optional) set this to False for a "production" environment.
   • FLASK_MAIL_SERVER: the hostname of an SMTP server which will accept mails. If you need more control over the SMTP settings, you can configure any of the usual Flask-Mail settings by creating appropriate files prefixed with FLASK_, e.g. FLASK_USE_TLS
   • NOTIFICATION_RECIPIENT: an email address that will receive emails when the system detects that new media has been added to Plex.
   • PLEX_TOKEN: A valid authentication token for accessing your Plex server. See the Plex Documentation for information on how to find this token.
   • PLEX_URL: the URL to your Plex server.
   • PLEXLIB_MOVIES_ROOT: (optional) The root directory for your Plex movie files. Default: /Volumes/Video/Movies.
   • PLEXLIB_TVSHOWS_ROOT: (optional) The root directory for your Plex TV show files. Default: /Volumes/Video/TV.
   • REDIS_URL: (optional) If you want to use a different access URL to the one above.
   • CELERY_BROKER_URL: (optional) If you want to use a different access URL to the one above.
   • (optional) Any file created with the prefix FLASK_ will be added to the Flask configuration.
   • (optional) Have a look at src/plexlib/config.py for other configuration parameters.

5. Run uWSGI in Emperor mode, pointing it at the directory containing the app configurations:

   uwsgi --emperor ./server/uwsgi

6. Create an nginx virtual host and point it at your Flask socket file. A sample configuration can be found at server/nginx/plexlib.

You can find a macOS plist file at server/macos/ch.harris.plexlib.plist. Copy this file to ~/Library/LaunchAgents (if you will be running without a logged-in user, you may want to put it instead in /Library/LaunchDaemons, but you may want to make additional changes to run the services as a different user). Edit the file and replace all the strings starting with "path to" with the appropriate path on your system.

Once the paths are correctly configured, you can start the service with the following command:

launchctl load ~/Library/LaunchAgents/ch.harris.plexlib.plist

The service will also start automatically whenever your user logs in.

A Dockerfile to build the main Flask application is provided at servers/docker/plexlib/flask/Dockerfile. The image can be built with the following command:

docker build -t plexlib -f server/docker/plexlib/flask/Dockerfile .

Without Redis and broker for Celery, the system will hang however, so a basic docker-compose configuration is provided at servers/docker/plexlib/docker-compose.yml.

Before bringing up the system, you should create the necessary environment in the servers/docker/plexlib/plexlib-envs.txt file - these will be used in the flask, celery, and celerybeat containers. Note: the REDIS_URL and CELERY_BROKER_URL variables should not be defined in this case as these are defined in the compose file so as to use the containerized services. Also, if the values for PLEXLIB_MOVIES_ROOT and PLEXLIB_TVSHOWS_ROOT need to be changed, they should be specified in the environment in which you're calling docker-compose, as these are mounted as volumes within the containers.

The following command will build the images and bring up the containers:

docker-compose -f server/docker/plexlib/docker-compose.yml up -d

The Docker configuration consists of the following six containers (one for each basic service) and expose the following ports on localhost:

• flask
• celery
• celerybeat
• nginx: port 8888, for normal HTTP access
• redis: port 6379, for access via redis-cli etc.
• rabbitmq: port 15672, for access to the RabbitMQ web management console

Sample output from docker ps is shown below:

CONTAINER ID        IMAGE                        COMMAND                  CREATED             STATUS              PORTS                                                                     NAMES
88d9f6357669        nginx:alpine                 "nginx -g 'daemon of…"   17 hours ago        Up 17 hours         80/tcp, 0.0.0.0:8888->8888/tcp                                            plexlib_nginx_1
6d1e08659f8f        plexlib_celery               "celery -A plexlib.t…"   17 hours ago        Up 17 hours                                                                                   plexlib_celery_1
fdd9aeef1f31        plexlib_flask                "uwsgi --master --so…"   17 hours ago        Up 17 hours         3031/tcp                                                                  plexlib_flask_1
e0b8c3b45b70        plexlib_celerybeat           "celery -A plexlib.t…"   17 hours ago        Up 17 hours                                                                                   plexlib_celerybeat_1
91c1d8bee470        rabbitmq:management-alpine   "docker-entrypoint.s…"   17 hours ago        Up 17 hours         4369/tcp, 5671-5672/tcp, 15671/tcp, 25672/tcp, 0.0.0.0:15672->15672/tcp   plexlib_rabbitmq_1
f236bbe3506d        redis:alpine                 "docker-entrypoint.s…"   17 hours ago        Up 17 hours         0.0.0.0:6379->6379/tcp                                                    plexlib_redis_1

To use Docker during development, you can run docker-compose and include the provided dev file:

docker-compose -f server/docker/plexlib/docker-compose.yml -f server/docker/plexlib/docker-compose.dev.yml up -d

This will replace the production uwsgi configuration in the flask container with a standard Flask development server, and mount the src and web directories in the container so that source code changes will be detected. Flask's standard port 5000 will also be exposed.

Tip To make working with docker-compse simpler, without having to specify the files on the commandline, you can rename docker-compose.dev.yml to docker-compose.override.yml. If you run docker-compse from the plexlib directly, it will then pick up the override file automatically:

cd server/docker/plexlib
docker-compose up -d

The system can be called two ways (assuming you are running on port 8888 as per the sample nginx configuration):

• Make a GET request to http://<your server>:8888/update/<section name>/

For example, if you wanted to update the "TV Shows" section, you could execute the following:

curl http://<your server>:8888/update/TV%20Shows/

• Make a POST request to http://<your server>:8888/update/from_name/, setting the value of name to a file name that can be found in your videos.

For example if you had a file named "My Fancy Show S07E22 Awesome Episode.mp4", you could execute the following:

curl -d 'name=My Fancy Show S07E22 Awesome Episode.mp4' http://<your server>:8888/update/from_name/

The PlexLib homepage provides a simple interface through which you can check that the server is working properly, and has a connection to your configured Plex Media Server. In addition, you can trigger an update for any of your library sections by clicking on the corresponding link.

To navigate to the homepage, assuming your server is running at localhost:8888, just point your browser to http://localhost:8888/.

As the original goal of this project was to automatically process emails from a Synology DiskStation, a sample biff-type utility is included at src/syno_media_biff.py, which can be used with procmail and a standard Python installation (no additional packages needed).

To use the biffer, add a rule to your procmail ruleset:

:0 fbw
* ^Subject:.*download task completed
| PLEXLIB_BASE_URL=http://<your server>:8888 syno_media_biff.py -e

The biffer will process the mail on standard input, and if it finds a new media file in the email, will call the PlexLib instance configured at PLEXLIB_BASE_URL. By using the -e option, the original content of the mail will be echoed to standard output, so you can deliver the mail as usual. The biffer adds additional information about the result of the PlexLib call to the end of the message.

Three "template" files are provided within the repository, which will most likely be modified during experimentation. To avoid git constantly reminding that the files have been modified, use the following commands, which will prevent git from tracking changes to the files within the working directory.

git update-index --skip-worktree envs/PLEX_*
git update-index --skip-worktree server/docker/plexlib/plexlib-envs.txt

• Dockerization
• Exception handling in celery tasks
• Reconnect listener if connection lost
• Add plist/s for running as services on macOS
• Compatibility with Python 3
• Tests