Add base Dockerfile and add caching for go build

[RonFed]

No description provided.

[damemi]

@RonFed could you please add some details about what this is doing? I also have a couple questions:

• Are we going to publish the new base image?
• What are the reasons for building a separate .base image over just multi-stage docker builds?

I'm assuming this helps with faster build times and maybe multi-arch builds? Is that just for our CI/builds or does that help users too?

[RonFed]

@RonFed could you please add some details about what this is doing? I also have a couple questions:

• Are we going to publish the new base image?
• What are the reasons for building a separate .base image over just multi-stage docker builds?

I'm assuming this helps with faster build times and maybe multi-arch builds? Is that just for our CI/builds or does that help users too?

Sure. The main motivation behind this is to make the build process faster for development. Running make docker-build or make docker-generate locally is made much faster with caching especially make docker-build. The base image saves re-downloading all the apt packages, and the --mount helps with caching the go packages.
I thought the separate base Dockerfile could be helpful for some of the Makefile targets (avoiding the apt installs). Can this be achieved by adding it as a build-stage?

[damemi]

Thanks for the explanation @RonFed!

I thought the separate base Dockerfile could be helpful for some of the Makefile targets (avoiding the apt installs). Can this be achieved by adding it as a build-stage?

No, I think what you're doing here is right for that. I just wasn't sure what the main goal was so I wanted to pose that question.

[RonFed]

@damemi I figured it is possible to do it with one Dokcerfile and use the base as the first stage, so I modified it back to a single file.

docker-build-base:
	docker buildx build -t $(IMG_NAME_BASE) --target base .