Docker healthcheck

[ylecuyer]

With the new docker healthcheck property I think this part of the entrypoint is no longer required:

https://github.com/docker-library/wordpress/blob/master/docker-entrypoint.sh#L170

Instead there should be a hint in the documentation to use healthy dependencies.

[yosifkit]

Copying comment from docker-library/cassandra#76 (comment)

I do not feel that generalized healthchecks on the official images are really that useful.

• users will have their own idea of what is "healthy"
• it does not actually test that the service is listening to connections outside of localhost (see https://github.com/docker-library/healthcheck for some examples that do more than what's proposed here, including attempting to check whether the service is listening remotely)
  • some of the Official Images even purposely start in a localhost only mode for database initialization and then kill and start the main service with full network availability
• after upgrading their images, current users will have extra unexpected load on their systems for healthchecks they don't necessarily need/want and may be unaware of