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You've implemented healthcheck in your Docker containers, right? Now you can get status of your containers with docker ps, but this is what you should do periodically. Wouldn't it be better to leave the job to some automatized solution? There are monitoring software tools like Zabbix, but if you found this too overkill for your solution, then there is docker-healthchecker libraries.

It's a simple Node.js library and CLI which can be used to obtain status and/or health of your containers. Simply ask for containers by image names or definition file and get useful info. Moreover, if you need, healthchecker can send status of your containers to Slack or display in console. Recommended usage is to install a CRON job, which periodically monitor your containers and send message to Slack if one or more of your containers is down or unhealthy.

Healthcheck is an instruction in Dockerfile which tells Docker how to test a container to check that it is still working. This is not same as running state of the container. For example, container with web server may be running, but could be in an infinite loop, which causes to not able to handle new connections.

Healthchecks could be defined in-line in Dockerfile, though more often is healthcheck a simple bash script which executes a test and exit with return value based on result of that test. Many services has healthcheck script included in repository along with Dockerfile, for another services you can use healthchecks made by community, for example here. In other cases you can write a healthcheck on your own (i.e. for healthchecking your app).

For more info about Docker healthchecks, see official documentation.

If you want to build own solution, which monitor your containers, then you can use docker-healthchecker-api, which provides REST API for the underlying docker-healthchecker. More info you can find on npm package info: https://www.npmjs.com/package/docker-healthchecker-api.

For a simple HTML status page containing a health of your containers, you can use docker-healthchecker-ui. More info you can find on npm package info: https://www.npmjs.com/package/docker-healthchecker-ui.

You can use this package either as a CLI application, Node.js library or in Docker container.

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Pull requests are welcome