Set some common parameters via environment

[ddrozdov]

Instead of creating custom a config file just to set a non-default elasticsearch port for example, it would be more convenient to be able to set it via the environment variables.
Like this:

docker run -d ... -e HOST=192.168.0.1 -e PORT=9999

See the example of this approach here: https://github.com/athieriot/docker-elastic-topbeat

I suggest to support this list of variables: PERIOD, HOST, PORT, SHIPPER_NAME, SHIPPER_TAGS.

[tsg]

Just a heads up, libbeat now supports setting env variables in the configuration files: elastic/beats#715

So dockerbeat could get this automatically by updating its libbeat version.

[marminthibaut]

Oh i try it right away!

[erwanncloarec]

I just tried, it does not seem to work with the current dockerbeat version.

We have to update libbeat for that