agrozyme/podman-qemu repository overview

⁠Summary

Source: https://gitlab.com/agrozyme-docker/podman-qemu⁠

Alpine-based image with podman and qemu. Easily allows cross platform image builds.

⁠Description

Inspired By jonoh/docker-buildx-qemu⁠

It's been tested with GitLab CI on gitlab.com

⁠Support Architectures

This Docker image can emulate the environments.

Use valid GOARCH values, see:

• GOARCH⁠
• official images architectures⁠

⁠Target Architectures

The Docker image can run in the environment (The intersection of Alpine and QEMU support platforms):

• amd64
• 386
• arm64
• arm
• ppc64le
• riscv64

⁠GitLab CI Template

It has two template files for building multi-platform Docker images.

• Single: For a single branch repository, deploy main to latest
• Multiple: Each branch is mapped to a docker image tag and the repository name is the same as Docker Registry.

⁠Docker Hub

• Single: /.gitlab/ci/single/docker-hub.yaml
• Multiple: /.gitlab/ci/multiple/docker-hub.yaml

⁠GitLab Container Registry

• Single: /.gitlab/ci/single/gitlab.yaml
• Multiple: /.gitlab/ci/multiple/gitlab.yaml

⁠Workflow:

• The main tag of the docker image is used to test the build.
• The build-one-arch job pushes the main tag of the docker image.
• When the build-one-arch job is successful, then the other build job pushes the multi-platform Docker image.
• After pushing the docker image, the build-metadata-push job will update the description of the Docker Hub repository.
  • Short description: The description of the project⁠.
  • Full description: README.md

⁠Environment variables

Put all docker image repositories into a Group and set Variables⁠ in CI / CD Settings

⁠Override priority

Put the variables in .gitlab-ci.yml or CI / CD Settings to override default.

• .gitlab-ci.yml stage variables
• .gitlab-ci.yml global variables
• Project CI / CD Settings
• Group CI / CD Settings

⁠Required

No default value, all variables are required. (Only for Docker Hub)

• DOCKER_HUB_USER: Login username
• DOCKER_HUB_PASS: Access token
  • See: https://docs.docker.com/security/for-developers/access-tokens⁠
• DOCKER_HUB_NAMESPACE:
  • username or organization
  • It will be passed to the Dockerfile as an ARG.

⁠Optional

• DOCKER_HUB_API_URL
  • The Docker Registry API url
  • Only use .gitlab-ci.yml to override
  • default: https://hub.docker.com/v2
• DOCKER_REGISTRY
  • The docker login server
  • Only use .gitlab-ci.yml to override
  • It will be passed to the Dockerfile as an ARG.
  • default: docker.io
• DOCKER_ARCH
  • The target architectures for building docker image.
  • default: amd64.
• DOCKER_TAG_SUFFIX
  • The tag suffix for multi-platform docker image, it will override DOCKER_ARCH

⁠Hook Scripts

It has two bash scripts to hook before_script and after_script, the scripts run at beginning and end of the docker build and push action.

• before_script.sh
• after_script.sh

Note:

• If you want to download the files during the build of docker image, you can do this by writing before_script.sh and using COPY command in the Dockerfile.
• It is just done once before / after the podman build and you can speed up the build of multi-platform docker image.

⁠Build Jobs

It define some tasks, you can combine for your tasks

⁠.build-one-arch

Build the same architecture image as the CI runner for quick testing of build scripts

⁠.build-all-arch

Build the DOCKER_ARCH architecture image

⁠.build-update-manifest

Create and push the manifest using DOCKER_ARCH

⁠.build-update-metadata

Update metadata to the docker registry

⁠Example

This GitLab example should give you an idea of how to use the image.

.gitlab-ci.yml

include:
  - project: agrozyme-docker/podman-qemu
    ref: main
    file: /.gitlab/ci/single/docker-hub.yaml

variables:
  DOCKER_ARCH: amd64,arm64

build-one-arch:
  extends:
    - .build-one-arch

build-all-arch:
  extends:
    - .build-all-arch
  parallel:
    matrix:
      - DOCKER_TAG_SUFFIX: [amd64, arm64]
  needs: ['build-one-arch']

build-manifest-create:
  extends:
    - .build-manifest-create
  needs: ['build-all-arch']

build-metadata-push:
  extends:
    - .build-metadata-push
  needs: ['build-manifest-create']