I have a project Magento 2. It has a folder docker. Please tell me how to deploy an existing project with the help of a docker? Is there a good tutorial? All I've found is installing a magenta using a docker, ie a new magenta, but I need to install the project.
This is not necessarily Magento specific. You can deploy your stack in many different ways:
Using Docker-Swarm, Rancher etc ..
For starters I would read this: https://docs.docker.com/get-started/part6/
If you are using gitlab_ci and want to deploy in the pipeline, read this: https://medium.com/@codingfriend/continuous-integration-and-deployment-with-gitlab-docker-compose-and-digitalocean-6bd6196b502a
Or simply google 'docker deployment'