Documentation for docker usage

[DrPyser]

It seems the docker image(https://quay.io/repository/prometheus/alertmanager) is lacking necessary documentation, such as internal ports to map, environment variables that can be used for configuration, etc.

Thanks!

[mxinden]

Thanks for the pointer @DrPyser. My suggestion would be to not sync the readme, but instead link to the Github one.

I don't have access to Quay. As far as I know @simonpasquier does? Would you mind removing the description and linking to https://github.com/prometheus/alertmanager/blob/master/README.md? What do you all think?

[simonpasquier]

I've updated the quay.io page. @DrPyser if you've got ideas to improve the README file, feel free to send a PR.

[mxinden]

Thanks @simonpasquier!

[DrPyser]

My suggestion would be to add information on things that one should know to use the image, like

• which environment variables can be used to configure the container
• which paths can/should be mapped to volumes for data persistence or configuration
• which ports are exposed(listened to) by the container process
• what command the container runs by default, and how that command can be modified/overridden.

Some of that information can be directly found in the Dockerfile, some might benefit from a better knowledge of the alertmanager command and intentions behind the Dockerfile.

[DrPyser]

#1865