Missing documentation to change logstash configuration about elk-docker

[spujadas]

Hi,

The general idea is in the documentation (http://elk-docker.readthedocs.org/#extending-the-image), but I'll add some more detailed information on changing configuration files.

In essence, here are your main options:

• You could fork the source of the image, change the config file and rebuild the image, but then you'd lose any additional goodness from future versions of the original image (unless you fork and update it on your side each time there's an upgrade).

• You could bind-mount (see https://docs.docker.com/engine/userguide/containers/dockervolumes/) your local configuration file to a configuration file within the container at runtime (e.g. docker run ... -v /path/to/your-30-output.conf:/etc/logstash/conf.d/30-output.conf), thus enabling you to tinker with the configuration file locally and have the changes dynamically update in the running container.

• You could also (if you're just playing around and testing things) exec into the running container and change the config files there, but that is indeed bad practice as the changes won't be persistent.

• Once you've finalised your configuration, you could make things permanent by creating a Dockerfile that extends the original image and replaces Logstash's config file with yours (or adds new config files). Goes something like this:

  FROM seb/elk
  
  ADD /path/to/your-logstash.conf /etc/logstash/conf.d/your-logstash.conf
  

Hope that helps.

[spujadas]

Closing following documentation update, feel free to reopen if still unclear.

[Schabernack]

Thanks a lot for your help Sébastien. I went with mounting the config file as a docker volume. Then, restarting with docker exec elk service logstash restart` allows me to quickly iterate different settings.

[spujadas]

Cheers!