Using custom docker image with Gitlab CI

Hi,

I need to use a custom docker image for continuous integration in Gitlab, especially as I need to embed custom SSL certificate in it, and would rather include some packages I need each time than installing them every time.

I know how to build a Docker image, and I read about the image property in .gitlab-ci.yml to choose which Docker image to choose, but I cannot find documentation about which is the correct starting point for a Docker CI image.

Do you know where I can find a base Dockerfile for a Docker-CI image?

Thanks

As far as I can tell, you can use any image. You need to make sure that you have the prerequisites available of course. I start from ubuntu:trusty but anything really works.