Good day Docker experts!
I’m relatively new to the game here, so please forgive me potentially silly question. I am currently working on building docker images inside of docker. using GitLab CI.
There are a myriad of example ways to accomplish this, and many recommendations include the necessity of running “docker-in-docker”.
(CAVEAT: due to this being my first post, I am limited to 2 links, so my usual external refs will be reduced, i’ll try to add a subsequent comment to my own topic w/ additional refs)
Now to my question, I’ve seen a few ways (and a few combinations of this).
- “image=docker:stable + service=docker-dnd”
- “image=docker:stable-dnd”
- “image=docker:stable-dnd + service=docker-dnd”
For the first, it looks roughly like this:
image: docker:stable
services:
- docker:dind
For the second, it looks roughly like this:
image: docker:stable-dind
Now there’s a third possibility of doing both:
image: docker:stable-dind
services:
- docker:dind
These definitely are official docker images, GitHub - docker-library/docker: Docker Official Image packaging for Docker
, and there are some clear differentiation to be gleaned in the code.
As per Run your CI/CD jobs in Docker containers | GitLab, we claim that a service is:
The
serviceskeyword defines just another Docker image that is run during your job and is linked to the Docker image that theimagekeyword defines. This allows you to access the service image during build time.
Therefore I am inclined to believe that option #3 is non-sense (or at least redundant). But still I’m uncertain which is the preferred way for #1 vs. #2.
Any insight / comments are greatly appreciated! Thanks.