GitLab Runner and Docker

Hello,
A website is built with Node.js and uses several microservices. The codes of this website are located in a GitLab server. I want to install GitLab Runner as a container. Is a GitLab Runner container required for each microservice?

Thank you.

Hello,
I am asking this question here because I know many people here have done this. My goal is:

GitLab Server ---> GitLab Runner and Docker Containers (Nginx, Node.js, Redis, etc.)

I saw something called gitlab-ci.yml, does this mean that Docker is running inside the GitLab server? If yes, then how can I stop this? I have run GitLab Runner and containers on another server and I want the codes to be read from the GitLab server and run on Docker Nginx and Node.js.

Thank you.