Docker Autoheal

Monitor and restart unhealthy docker containers. This functionality was proposed to be included with the addition of HEALTHCHECK, however didn't make the cut. This container is a stand-in till there is native support for --exit-on-unhealthy https://github.com/docker/docker/pull/22719.

Supported tags and Dockerfile links

• latest (Dockerfile) - Built daily
• 1.1.0 (Dockerfile)
• v0.7.0 (Dockerfile)

How to use

UNIX socket passthrough

docker run -d \
    --name autoheal \
    --restart=always \
    -e AUTOHEAL_CONTAINER_LABEL=all \
    -v /var/run/docker.sock:/var/run/docker.sock \
    willfarrell/autoheal

TCP socket

docker run -d \
    --name autoheal \
    --restart=always \
    -e AUTOHEAL_CONTAINER_LABEL=all \
    -e DOCKER_SOCK=tcp://HOST:PORT \
    -v /path/to/certs/:/certs/:ro \
    willfarrell/autoheal

a) Apply the label autoheal=true to your container to have it watched.

b) Set ENV AUTOHEAL_CONTAINER_LABEL=all to watch all running containers.

c) Set ENV AUTOHEAL_CONTAINER_LABEL to existing label name that has the value true.

Note: You must apply HEALTHCHECK to your docker images first. See https://docs.docker.com/engine/reference/builder/#healthcheck for details. See https://docs.docker.com/engine/security/https/ for how to configure TCP with mTLS

The certificates, and keys need these names:

• ca.pem
• client-cert.pem
• client-key.pem

Change Timezone

If you need the timezone to match the local machine, you can map the /etc/localtime into the container.

docker run ... -v /etc/localtime:/etc/localtime:ro

ENV Defaults

AUTOHEAL_CONTAINER_LABEL=autoheal
AUTOHEAL_INTERVAL=5   # check every 5 seconds
AUTOHEAL_START_PERIOD=0   # wait 0 seconds before first health check
AUTOHEAL_DEFAULT_STOP_TIMEOUT=10   # Docker waits max 10 seconds (the Docker default) for a container to stop before killing during restarts (container overridable via label, see below)
DOCKER_SOCK=/var/run/docker.sock   # Unix socket for curl requests to Docker API
CURL_TIMEOUT=30     # --max-time seconds for curl requests to Docker API
WEBHOOK_URL=""    # post message to the webhook if a container was restarted (or restart failed)

Optional Container Labels

autoheal.stop.timeout=20        # Per containers override for stop timeout seconds during restart

Testing

docker build -t autoheal .

docker run -d \
    -e AUTOHEAL_CONTAINER_LABEL=all \
    -v /var/run/docker.sock:/var/run/docker.sock \
    autoheal