docker2mqtt - Deliver docker status information over MQTT

This program uses docker events to watch for changes in your docker containers, and docker stats for metrics about those containers, and delivers current status to MQTT. It will also publish Home Assistant MQTT Discovery messages so that (binary) sensors automatically show up in Home Assistant.

This is part of a family of similar tools:

• miaucl/linux2mqtt
• miaucl/docker2mqtt
• miaucl/systemctl2mqtt

Installation and Deployment

It is available as python package on pypi/docker2mqtt or as a docker image on ghcr.io/docker2mqtt.

Pypi package

pip install docker2mqtt
docker2mqtt --name MyDockerName --events -vvvvv

Usage

from docker2mqtt import Docker2Mqtt, DEFAULT_CONFIG

cfg = Docker2MqttConfig({ 
  **DEFAULT_CONFIG,
  "host": "mosquitto",
  "enable_events": True
})

try:
  docker2mqtt = Docker2Mqtt(cfg)
  docker2mqtt.loop_busy()

except Exception as ex:
  # Do something

Docker image

Use docker to launch this. Please note that you must give it access to your docker socket, which is typically located at /var/run/docker.sock. A typical invocation is:

docker run --network mqtt -e MQTT_HOST=mosquitto -v /var/run/docker.sock:/var/run/docker.sock ghcr.io/miaucl/docker2mqtt

You can also use docker compose:

services:
  docker2mqtt:
    container_name: docker2mqtt
    image: ghcr.io/miaucl/docker2mqtt
    environment:
      - DOCKER2MQTT_HOSTNAME=my_docker_host
      - MQTT_HOST=mosquitto
      - MQTT_USER=username
      - MQTT_PASSWD=password
      - EVENTS=1
      - STATS=1
    restart: unless-stopped
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro

Default Configuration

You can use environment variables to control the behavior.

Config	Env Variable	Default	Description
log_level	LOG_LEVEL	INFO	Set to DEBUG,INFO,WARN,ERROR,CRITICAL to enable different levels of verbosity.
docker2mqtt_hostname	DOCKER2MQTT_HOSTNAME	docker2mqtt Container Hostname	The hostname of your docker host. This will be the container's hostname by default, you probably want to override it.
homeassistant_prefix	HOMEASSISTANT_PREFIX	homeassistant	The prefix for Home Assistant discovery. Must be the same as discovery_prefix in your Home Assistant configuration.
mqtt_client_id	MQTT_CLIENT_ID	mqtt2discord	The client id to send to the MQTT broker.
mqtt_host	MQTT_HOST	localhost	The MQTT broker to connect to.
mqtt_port	MQTT_PORT	1883	The port on the broker to connect to.
mqtt_user	MQTT_USER		The user to send to the MQTT broker. Leave unset to disable authentication.
mqtt_password	MQTT_PASSWD		The password to send to the MQTT broker. Leave unset to disable authentication.
mqtt_timeout	MQTT_TIMEOUT	30	The timeout for the MQTT connection.
mqtt_topic_prefix	MQTT_TOPIC_PREFIX	docker	The MQTT topic prefix. With the default data will be published to docker/<hostname>.
mqtt_qos	MQTT_QOS	1	The MQTT QOS level
container_whitelist	CONTAINER_WHITELIST		Define a whitelist for containers to consider, if empty, everything is monitored. The entries are either match as literal strings or as regex.
container_blacklist	CONTAINER_BLACKLIST		Define a blacklist for containers to consider, takes priority over whitelist. The entries are either match as literal strings or as regex.
destroyed_container_ttl	DESTROYED_CONTAINER_TTL	86400	How long, in seconds, before destroyed containers are removed from Home Assistant. Containers won't be removed if the service is restarted before the TTL expires.
stats_record_seconds	STATS_RECORD_SECONDS	30	The number of seconds to record state and make an average
enable_events	EVENTS	0	1 Or 0 for processing events
enable_stats	STATS	0	1 Or 0 for processing statistics

Consuming The Data

Data is published to the topic docker/<DOCKER2MQTT_HOSTNAME>/<container>/events using JSON serialization. It will arrive whenever a change happens and its type can be inspected in type_definitions.py or the documentation.

Data is also published to the topic docker/<DOCKER2MQTT_HOSTNAME>/<container>/stats using JSON serialization. It will arrive every STATS_RECORD_SECONDS seconds or so and its type can be inspected in type_definitions.py or the documentation.

Home Assistant

Once docker2mqtt is collecting data and publishing it to MQTT, it's rather trivial to use the data in Home Assistant.

A few assumptions:

• Home Assistant is already configured to use a MQTT broker. Setting up MQTT and HA is beyond the scope of this documentation. However, there are a lot of great tutorials on YouTube. An external broker (or as add-on) like Mosquitto will need to be installed and the HA MQTT integration configured.
• The HA MQTT integration is configured to use homeassistant as the MQTT autodiscovery prefix. This is the default for the integration and also the default for docker2mqtt. If you have changed this from the default, use the --prefix parameter to specify the correct one.
• You're not using TLS to connect to the MQTT broker. Currently docker2mqtt only works with unencrypted connections. Username / password authentication can be specified with the --username and --password parameters, but TLS encryption is not yet supported.

After you start the service (binary) sensors should show up in Home Assistant immediately. Look for sensors that start with (binary_)sensor.docker. Metadata about the container will be available as attributes for events, which you can then expose using template sensors if you wish.

Documentation

Using mkdocs, the documentation and reference is generated and available on github pages.

Dev

Setup the dev environment using VSCode, it is highly recommended.

python -m venv .venv
source .venv/bin/activate
pip install -r requirements_dev.txt

Install pre-commit

pre-commit install

# Run the commit hooks manually
pre-commit run --all-files

Following VSCode integrations may be helpful:

• ruff
• mypy
• markdownlint

Releasing

It is only possible to release a final version on the master branch. For it to pass the gates of the publish workflow, it must have the same version in the tag, the setup.cfg, the bring_api/__init__.py and an entry in the CHANGELOG.md file.

To release a prerelease version, no changelog entry is required, but it can only happen on a feature branch (not master branch). Also, prerelease versions are marked as such in the github release page.

Credits

This is a detached fork from the repo https://github.com/skullydazed/docker2mqtt, which does not seem to get evolved anymore.