docker language - benclifford/text GitHub Wiki

Extensions that I'd like to dockerfile-like language that address weaknesses that I've worked around a bit on previous projects

(based in part on experience in production)

• ability to add subdirs without sending entire pwd as context:

  use: monorepo, want to add subdirs A/ and B/ into image but dont care about C/, D/ .. Z/ and those latter ones are very large so expensive and wasteful to ship to docker daemon only to be ignored.

current workaround: in haskell, build image with A/ pwd, then build another image with B/ pwd, chained on from first build with dynamic image ID

• cache invalidation

workarounds:

• explicit token in ENV / ADD a force file, and code to figure it out.

• explicitly named intermediate steps (eg. component.requirements build depending on the requirements.txt file)

  • docker does this already but I've been in situations where I have wanted things done a bit differently (eg using a shared wheel directory, or getting access to the requirements install image without the end component installed)

• local tags / local naming

• scoped eg to local tree

• shared filesystem at build

• for local caches. argument against is weak when build also allows access to the internet which is totally non-deterministic.

workaround: run those commands as a docker run / docker image snapshot

• out of tree dockerfiles / machine generated docker files

though this is perhaps a side-effect of working around the stuff above?

workaround: generate into tree. run docker. delete.

main problem with generating into tree and not deleting is your tree is now dirty.

more generally, build environment is very much a "package this subtree off and send it over" style, which gives certain constraints.