Container-Mon
Get notified when your Docker containers are unhealthy.
Prerequisites
- Have Go 1.18+ or Docker installed
- A notification service supported by Shoutrrr and the required API keys or other configuration for your chosen service (e.g: Telegram, Discord, Slack, Teams etc)
Configuration
All configuration is done via environment variables, see the table below for all options and default values. Only CONTAINERMON_NOTIFICATION_URL is mandatory, all other fields are optional. |
Name | Type | Default Value | Description | |
|---|---|---|---|---|---|
| CONTAINERMON_FAIL_LIMIT | Int | 1 | Number of consecutive 'unhealthy' checks to reach before sending a notification | ||
| CONTAINERMON_CRON | String | /5 * | Standard Cron schedule of when to run healthchecks | ||
| CONTAINERMON_NOTIFICATION_URL | String | N/A | Notification URL for Shoutrrr. Multiple services can be used with the \| (pipe) character as a separator. |
||
| CONTAINERMON_USE_LABELS | Bool | false | If true will only monitor containers with the label containermon.enable=true set |
||
| CONTAINERMON_NOTIFY_HEALTHY | Bool | true | If true will send a notification when an 'unhealthy' container returns to being 'healthy' |
||
| CONTAINERMON_CHECK_STOPPED | Bool | true | If true will consider stopped containers as 'unhealthy'. If false, you will only be notified for containers that have a healthcheck set |
||
| CONTAINERMON_MESSAGE_PREFIX | String | N/A | Custom text to be prefixed to all notification messages. | ||
| DOCKER_HOST | String | /var/run/docker.sock | Path for the Docker API socket | ||
| DOCKER_API_VERSION | String | docker default | Docker API version to use | ||
| DOCKER_CERT_PATH | String | docker default | Path to load the TLS certificates from | ||
| DOCKER_TLS_VERIFY | Bool | false | Enable or disable TLS verification |
Usage
- Stand-alone:
go run app.go - Docker:
docker run \ -v /var/run/docker.sock:/var/run/docker.sock \ -e CONTAINERMON_NOTIFICATION_URL=telegram://token@telegram?channels=channel-1 \ ghcr.io/rafhaanshah/container-mon:latest - Docker-Compose:
version: "3.8" services: container-mon: container_name: container-mon image: ghcr.io/rafhaanshah/container-mon:latest restart: unless-stopped volumes: - /var/run/docker.sock:/var/run/docker.sock environment: - CONTAINERMON_NOTIFICATION_URL=telegram://token@telegram?channels=channel-1
Troubleshooting
- Docker API version issues: if you get error messages like
client version 1.43 is too new. Maximum supported API version is 1.42then please set theDOCKER_API_VERSIONenvironment variable to the latest version supported by your Docker engine (e.g.DOCKER_API_VERSION=1.42, which you can check by runningdocker version. - Notifier issues: please check if your URL works with the Shoutrrr CLI from here.
Security Considerations
- It can be considered a security risk to directly map your Docket socket inside a container. A proxy such as Socket-Proxy can be used to give fine-grained access to parts of the Docker API, this application only needs to be able to read a list of running containers ->
docker run \ -e DOCKER_HOST=tcp://socket-proxy:2375 ... - This container runs as
rootby default to access the Docker socket. You may run it as another user that has access to the socket as described here: Running a Docker container as a non-root user ->docker run \ -u $(id -u):$(stat -c '%g' "/var/run/docker.sock") \ ...