I think I might be the only one that prefers Docker for building Docker containers using CI.
I use Drone, but instead of using the Docker plugin I start a detached (background) Caddy server to work as a proxy to DOCKER_HOST. That lets me proxy to the local Docker socket to take advantage of caching, etc. while I'm iterating, but gives the option of spinning up docker-in-docker to get a clean environment, without any caching, and running a slower build that virtually identical to what happens on the CI server.
I find that having the daemon available solves a ton of issues that most of the CI provided builder plugins have. For example, with the builder plugins I'd always end up with a step like build-and-tag-and-push which didn't work very well for me. Now I can run discreet build steps like build, test, tag, push and it feels far more intuitive, at least to me.
I use Drone, but instead of using the Docker plugin I start a detached (background) Caddy server to work as a proxy to DOCKER_HOST. That lets me proxy to the local Docker socket to take advantage of caching, etc. while I'm iterating, but gives the option of spinning up docker-in-docker to get a clean environment, without any caching, and running a slower build that virtually identical to what happens on the CI server.
I find that having the daemon available solves a ton of issues that most of the CI provided builder plugins have. For example, with the builder plugins I'd always end up with a step like build-and-tag-and-push which didn't work very well for me. Now I can run discreet build steps like build, test, tag, push and it feels far more intuitive, at least to me.