Consider using service healthcheck in Dockerfile

[dborovcanin]

ENHANCEMENT

1. Describe the enhancement you are requesting.
   We should consider using internal health check endpoints for exposing in Dockerfile like it's mentioned here.
2. Indicate the importance of this enhancement to you (must-have, should-have, nice-to-have).
   This is a should-have enhancemenet.

[dborovcanin]

The only problem I see is that we need an external HTTP client to use our HTTP API health check endpoint (like in this example) and we are using scratch as a base image. However, there is always an option to create a simple Go binary instead of using tools such as curl.

[blokovi]

What I found interesting is that official docker images on docker hub do NOT have healtcheks.
Here are the reasons: https://github.com/docker-library/faq#healthcheck

Also, healthchecks can be implemented in docker-compose, instead of in docker images, so given these reasons it may be better to use it there instead of Dockerfile

[dborovcanin]

What I found interesting is that official docker images on docker hub do NOT have healtcheks. Here are the reasons: https://github.com/docker-library/faq#healthcheck

Also, healthchecks can be implemented in docker-compose, instead of in docker images, so given these reasons it may be better to use it there instead of Dockerfile

These reasons sound sane to me. That is, we leave health checking to the user, and provide an endpoint that can be used for that. If @mainflux/maintainers agree, I will close this one.

[dborovcanin]

Closing this one due to reasons @blokovi explained in the comment.