# buildah-build
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[](https://github.com/redhat-actions/buildah-build/actions?query=workflow%3ABuild)
[](https://github.com/redhat-actions/buildah-build/actions?query=workflow%3A%22Build+from+dockerfile%22)
[](https://github.com/redhat-actions/buildah-build/actions?query=workflow%3A%22Link+checker%22)
[](https://github.com/redhat-actions/buildah-build/tags)
[](./LICENSE)
[](./dist)
Buildah is a GitHub Action for building Docker and Kubernetes-compatible images quickly and easily.
Buildah only works on Linux. GitHub's [Ubuntu Environments](https://github.com/actions/virtual-environments#available-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](https://github.com/containers/buildah/blob/master/install.md).
After building your image, use [push-to-registry](https://github.com/redhat-actions/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](#multi-arch-builds) to setup the `qemu-user-static` dependency. | `amd64`
| 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**
| 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. Refer to [Multi arch builds](#multi-arch-builds) to setup the `qemu-user-static` dependency. | `amd64`
| 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
| context | Path to directory to use as the build context. | `.`
| 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`.
```yaml
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 ${{ github.sha }}
dockerfiles: |
./Dockerfile
build-args: |
some_arg=some_value
```
### Building without a Dockerfile
Building without a Dockerfile requires additional inputs, that would normally be specified in the Dockerfile.
Do not set `dockerfiles` if you are doing a build from scratch. Otherwise those Dockerfiles will be used, and the inputs below will be ignored.
- An output `image` name and usually a `tag`.
- `base-image`
- In a Dockerfile, this would be the `FROM` directive.
- `content` to copy into the new image
- In a Dockerfile, this would be `COPY` directives.
- `entrypoint` so the container knows what command to run.
- In a Dockerfile, this would be the `ENTRYPOINT`.
- All other optional configuration inputs, such as `port`, `envs`, and `workdir`.
Example of building a Spring Boot Java app image:
```yaml
name: Build Image
on: [push]
jobs:
build-image:
name: Build image without Dockerfile
runs-on: ubuntu-latest
steps:
- uses: actions/checkout@v2
- run: mvn package
- name: Build Image
uses: redhat-actions/buildah-build@v2
with:
base-image: docker.io/fabric8/java-alpine-openjdk11-jre
image: my-new-image
tags: v1
content: |
target/spring-petclinic-2.3.0.BUILD-SNAPSHOT.jar
entrypoint: java -jar spring-petclinic-2.3.0.BUILD-SNAPSHOT.jar
port: 8080
```
## Multi arch builds
If building for an architecture other than `amd64`, install `qemu-user-static` using the following command.
```
sudo podman run --rm --privileged multiarch/qemu-user-static --reset -p yes
```
## Using private images
If your build requires a private image, you have to `docker login` in a step before running this action.
For example:
```yaml
- name: Log in to Red Hat Registry
run: echo "${{ secrets.REGISTRY_REDHAT_IO_PASSWORD }}" | docker login registry.redhat.io -u "${{ secrets.REGISTRY_REDHAT_IO_USER }}" --password-stdin
```