At Codex, we are using Nim programming language. Some of our projects are using pre-compiled Nim in Docker for Docker images to simplify and speed up the builds.

Also, we are using multi-arch Docker images and for that it is required to have multi-arch source images and we have the following issues with that

⏳ Make Nim docker images official?
⏳ Provide official docker image #515
❌ moigagoo/nimage - Only amd64, outdated
📜 theAkito/docker-nim - License, outdated
🛠️ arm support for Linux #23

Code in the repository provides a simple way to build multi-arch Docker images with a required Nim version. However, builds are triggered manually.

For builds we are using GitHub Actions and rely on nimv for Nim installation.

Considerations

We are using only amd64 and arm64 architecture
We are using ubuntu for our apps container and use it for nim-lang as well
Multi-platform builds using QEMU are very slow 1h56m vs 12m

Docker images

Images are pushed and available on DockerHub

docker run --rm codexstorage/nim-lang:2.0.14 nim --version

Build your own images

Fork the repository.
Add GitHub Actions secrets - DOCKERHUB_USERNAME and DOCKERHUB_TOKEN.
Adjust workflow with your repository name.
Run workflow and pass required Nim version.

Build manually

Multi-platform builds

On separate VMs

Build guide

Build Docker images on separate VMs

Run amd64(cx32 ,cpx31) and arm64(cax21) VMs on Hetzner
Install Docker
Clone repository
```
git clone
```

Define variables

repository="codexstorage/nim-lang"
nim_version="2.0.14"

Run the build on each VM

docker build \
  --tag nim-lang:"${nim_version}" \
  --build-arg NIM_VERSION="${nim_version}" \
  --file Dockerfile .

Push image and get the digest on each VM

docker image tag nim-lang:"${nim_version}" "${repository}:${nim_version}"

docker image push ${repository}:${nim_version}

We will get a digest for each image and we need to define appropriate variables

amd64="sha256:43c1ea16d34528b3f195e18ca21f69987a01daaf0ddd5d94b252d37ebace2f5c"
arm64="sha256:4b4b3d6617c9bc698adefd0a27d1d18c5236016b92ee7ddc8c42311586568d91"

Create a manifest list for multi-arch image and push it from on one of the VM

docker buildx imagetools create \
  -t "${repository}:${nim_version}" \
  "${amd64}" \
  "${arm64}"

Duration

Platform	Build	Push	Size
`amd64`	`8m20.221s`	`1m17.620s`	`659MB`
`arm64`	`10m20.591s`	`0m48.888s`	`676MB`

TOTAL: ~ 11m09s

On a single VM

Build guide

Build Docker images on a single VM

Run amd64(cx32 ,cpx31) VM on Hetzner
Install Docker
Clone repository
```
git clone
```

Define variables

repository="codexstorage/nim-lang"
nim_version="2.0.14"

Create a custom builder

docker buildx create \
--name container-builder \
--driver docker-container \
--bootstrap --use

Run the build for multiple platforms

docker buildx build \
  --tag "${repository}:${nim_version}" \
  --build-arg NIM_VERSION="${nim_version}" \
  --platform linux/amd64,linux/arm64 \
  --push \
  --file Dockerfile .

Duration

Platform	Build	Push	Size
`amd64`	`-`	`-`	`613MB`
`arm64`	`13m55.177s`	`0m42.444s`	`425MB`

TOTAL: ~ 14m35s

Known issues

We are using nimv which requires bash, so alpine images will not work.