terrorizer1980/buildah-build

GitHub Action to use 'buildah' to build a container image.

buildah-build

Buildah Build is a GitHub Action for building Docker and Kubernetes-compatible images quickly and easily.

Buildah only works on Linux. GitHub's Ubuntu Environments (ubuntu-18.04 and newer) come with buildah installed. If you are not using these environments, or if you want to use a different version, you must first install buildah.

After building your image, use push-to-registry to push the image and make it pullable.

Action Inputs

Inputs for build from dockerfile

Input Name	Description	Default
archs	Architecture(s) to build the image(s) for. For multiple architectures, separate by a comma. Refer to Multi arch builds to setup the qemu-user-static dependency.	None (host architecture)
build-args	Build arguments to pass to the Docker build using --build-arg, if using a Dockerfile that requires ARGs. Use the form arg_name=arg_value, and separate arguments with newlines.	None
context	Path to directory to use as the build context.	.
dockerfiles	The list of Dockerfile paths to perform a build using docker instructions. This is a multiline input to allow multiple Dockerfiles.	Must be provided
extra-args	Extra args to be passed to buildah bud. Separate arguments by newline. Do not use quotes.	None
image	Name to give to the output image.	Must be provided
layers	Set to true to cache intermediate layers during the build process.	None
oci	Build the image using the OCI format, instead of the Docker format. By default, this is false, because images built using the OCI format have issues when published to Dockerhub.	false
tags	The tags of the image to build. For multiple tags, separate by a space. For example, latest ${{ github.sha }}	latest

Inputs for build without dockerfile

Input Name	Description	Default
archs	Architecture(s) to build the image(s) for. For multiple architectures, separate by a comma.	None (host architecture)
base-image	The base image to use for the container.	Must be provided
content	Paths to files or directories to copy inside the container to create the file image. This is a multiline input to allow you to copy multiple files/directories.	None
entrypoint	The entry point to set for the container. This is a multiline input; split arguments across lines.	None
envs	The environment variables to be set when running the container. This is a multiline input to add multiple environment variables.	None
image	Name to give to the output image.	Must be provided
oci	Build the image using the OCI format, instead of the Docker format. By default, this is false, because images built using the OCI format have issues when published to Dockerhub.	false
port	The port to expose when running the container.	None
tags	The tags of the image to build. For multiple tags, separate by a space. For example, latest ${{ github.sha }}	latest
workdir	The working directory to use within the container.	None

Action Outputs

image: The name of the built image.
For example, spring-image.

tags: A list of the tags that were created, separated by spaces.
For example, latest ${{ github.sha }}.

Build Types

You can configure the buildah action to build your image using one or more Dockerfiles, or none at all.

Building using Dockerfiles

If you have been building your images with an existing Dockerfile, buildah can reuse your Dockerfile.

In this case the inputs needed are image and dockerfiles. tag is also recommended. If your Dockerfile requires ARGs, these can be passed using build-arg.

name: Build Image using Dockerfile
on: [push]

jobs:
  build:
    name: Build image
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - name: Buildah Action
      uses: redhat-actions/buildah-build@v2
      with:
        image: my-new-image
        tags: v1 ${{ github.sha }}
        dockerfiles: |
          ./Dockerfile
        build-args: |
          some_arg=some_value

Building without a Dockerfile

Building without a Dockerfile requires additional inputs, that would normally be specified in the Dockerfile.

Do not set dockerfiles if you are doing a build from scratch. Otherwise those Dockerfiles will be used, and the inputs below will be ignored.

• An output image name and usually a tag.
• base-image
  • In a Dockerfile, this would be the FROM directive.
• content to copy into the new image
  • In a Dockerfile, this would be COPY directives.
• entrypoint so the container knows what command to run.
  • In a Dockerfile, this would be the ENTRYPOINT.
• All other optional configuration inputs, such as port, envs, and workdir.

Example of building a Spring Boot Java app image:

name: Build Image
on: [push]

jobs:
  build-image:
    name: Build image without Dockerfile
    runs-on: ubuntu-latest

    steps:
    - uses: actions/checkout@v2

    - run: mvn package

    - name: Build Image
      uses: redhat-actions/buildah-build@v2
      with:
        base-image: docker.io/fabric8/java-alpine-openjdk11-jre
        image: my-new-image
        tags: v1
        content: |
          target/spring-petclinic-2.3.0.BUILD-SNAPSHOT.jar
        entrypoint: java -jar spring-petclinic-2.3.0.BUILD-SNAPSHOT.jar
        port: 8080

Multi arch builds

Cross-architecture builds from dockerfiles containing RUN instructions require qemu-user-static emulation registered in the Linux kernel. Run sudo apt install -y qemu-user-static on Debian-based container hosts. Or run the following registration command for other distributions:

sudo podman run --rm --privileged docker.io/tonistiigi/binfmt --install all

The registration remains active until the container host reboots.

Using private images

If your build references a private image, run podman-login in a step before this action so you can pull the image. For example:

- name: Log in to Red Hat Registry
  uses: redhat-actions/podman-login@v1
  with:
    registry: registry.redhat.io
    username: ${{ secrets.REGISTRY_REDHAT_IO_USER }}
    password: ${{ secrets.REGISTRY_REDHAT_IO_PASSWORD }}