haskell-docker-builder

Package Haskell binaries into docker images.

Use case:

If you can build statically linked binaries, you are better off using busybox directly. This approach is helpful when your executable is dependent on dynamically linked libraries.

Quick start:

You can drop this Makefile into your project directory. This is assuming that your project uses stack. It can be easily modified to work with cabal. Replace project and registry with your own values.

project  := myproject
registry := myregistry

project_dir := $(shell pwd)
build_dir   := $(project_dir)/$(shell stack path --dist-dir)/build
version     := $(shell grep -oP '^version:\s*\K.*' $(project).cabal)

image: $(project).cabal
	stack build
	docker run --rm -v $(build_dir)/$(project)-exe/$(project)-exe:/root/$(project)-exe hasura/haskell-docker-packager:1.0 /build.sh $(project)-exe | docker import - $(registry)/$(project):$(version)

push: $(project).cabal
	docker push $(registry)/$(project):$(version)

You can now use make image to create the docker image.

How does this work

The make image rule builds a bare minimal root filesystem with the haskell binary and all necessary libraries. This filesystem is imported as an image into docker.

The compiled binary is mounted into a debian builder image. A script inside the image processes the binary and copies all dynamically linked libraries into the root filesystem.

Customising the builder image

You'll need to customise the builder image to add the libraries needed for the executable. For example, if the dependency is libpq, you can do this:

FROM hasura/haskell-docker-packager:1.0
RUN <apt install the library>

Update the Makefile to use this new image instead of haskell-docker-packager.