Run docker pull before building images

[nitrocode]

what

• Run docker pull before building images

why

• This should speed up images by downloading the existing image first

references

• https://github.com/docker/build-push-action

[Tenzer]

I don't think this does what you think it does. The option adds the --pull argument to the underlying docker build command, which only makes sure the base image is up to date prior to building the new image. It doesn't pull the same image that you are about to build.

If you want to speed up the image builds by using caching, you instead need to look at the cache-from and cache-to options, as described in https://docs.docker.com/build/ci/github-actions/examples/#cache-backend-api.

[nitrocode]

Thanks @Tenzer for pointing that out. Please feel free to put in a PR. We would like to take advantage of caching to speed up our builds.

[Tenzer]

Sure, I have done that in #2737.