[feature request] Allow overriding of configuration parameters using environment variables

[mnuessler]

I would like to suggest the following feature or rather ask for your opinion about it.

When running InfluxDB in a docker container and I need to modify the configuration, I have basically two options:

1. I can include the config file in the docker image and rebuild the image with the updated config or
2. I can mount the config from the host file system and edit it there.

If it was possible to override configuration parameters through environment variables, then it would be much easier: Just set the environment variable and restart the container. This is also the approach implemented by Grafana (see the Grafana documentation).

What do you think of this approach?

[mnuessler]

Thanks for implementing this!