I am currently running a Jenkins with Docker. When trying to build docker apps, i am facing some doubt on if i should use Docker in Docker (Dind) by binding the /var/run/docker.sock file or by installing another instance of docker in my Jenkins Docker. I actually saw that previously, it was discouraged to use something else than the docker.sock.
I don't actually understand why we should use something else than the docker daemon from the host apart from not polluting it.
Best solution for "jenkins in docker container needs docker" case is to add your host as a node(slave) in jenkins. This will make every build step (literally everything) run in your host machine. It took me a month to find perfect setup.
Mount docker socket in jenkins container: You will lose context. The files you want to COPY inside image is located inside workspace in jenkins container and your docker is running at host. COPY fails for sure.
Install docker client in jenkins container: You have to alter official jenkins image. Adds complexity. And you will lose context too.
Add your host as jenkins node: Perfect. You have the contex. No altering the official image.