Allow filter out user-defined images

[Nikita Krochak]

I use docker/build-push-action to build and cache some images so I'd like to use your action to cache only images that's not already in the docker/build-push-action cache (only images that doesn't require build such as Elasticsearch, Redis, Database). Currently I have these images in both caches that is not good.

Would be nice to have something like this in action config:

                with:
                    exclude-images: image1:latest, image2:2.0

Should not be difficult to do due to most of the work done in #98.

[Kurt von Laven]

I am guessing you aren't able to simply call docker/build-push-action before calling ScribeMD/docker-cache?

[Nikita Krochak]

Nah, it works fine. The only issue I see is double caching.

You could take a look at my CI to better understand the problem.

Here's CI run on empty cache. As you can see docker/build-push-action done it's job fine. And ScribeMD/docker-cache found no cache which is also fine and expected. But in ScribeMD/docker-cache POST action the image that is built and cached in docker/build-push-action is cached again (it's name encrypted via Github Actions env variables so it looks like ***:latest).
And here's CI run after that with warmed up cache. At this place docker/build-push-action has prepared built image layers cache and ScribeMD/docker-cache has loaded this image from its cache.

So I'd like to manually remove image built with docker/build-push-action from the list of images that ScribeMD/docker-cache saves to its cache. Adding some kind of action's option would be the simplest solution so I suggested this.

[Kurt von Laven]

Thank you for the additional details. I would try adding load: true to docker/build-push-action since ScribeMD/docker-cache already filters out the images that are present before it is run. As you can see from its output in the cache miss case, the built image is not found during the main step but is found during the post step.

[Nikita Krochak]

Thanks for the advice! Now it works fine. I had to split my docker/build-push-action single action in two different ones like in this example. Otherwise you can't use both push and load options.
But in the end caching pulled images is still slower than pulling them... At least in my case. I hope at some point with some amount of images it changes so I can use this action sometime later!

[Kurt von Laven]

Oh, where are you pulling the images that are being cached with ScribeMD/docker-cache from? If you are able to pull from the GitHub Container Registry, that will perform the fastest in GitHub Actions.