For example, you have a few servers with different environments like test, and prod. And you want to apply GitLab CI/CD, should you install gitlab-runner on each server or install it on a separate machine. Which one is better or are there any so-called best practices. More on forum.gitlab.com

You should use SSH-keys which are stored in Gitlab CI secret variables / environment variables, then connect to your servers and deploy. I suggest using ansible for this purpose. Do not install the CI runner on any of your servers, keep it on a separate box. More on reddit.com

I don't want to run my code, I just want to compile it The executor executes your build script, compiling is the stuff you would put in your build script. So no, it's not really for running your actual application. Docker is useful for this because it's isolated, you could also run it directly on your machine but setting up build environments manually sucks. It's better to invest a bit of time to find / create docker images you can use for your builds. For popular tools, many have official docker images anyway. It's not a stupid restriction, I have set up both runners using the shell (or whatever it's called exactly) and docker and both were painless & fast to set up and use. More on reddit.com

i always have the issue of starting the runner with systemctl gitlab-runner start , it just freezes or it didn't work, every time I start it in background with gitlab-runner run &, any idea ? More on reddit.com