Merge pull request #299 from crazy-max/split-docs

Enhance documentation
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551
README.md

@ -6,18 +6,18 @@
## Upgrade from v1
`v2` of this action includes significant updates and now uses Docker [Buildx](https://github.com/docker/buildx). It
works with 3 new actions ([login](https://github.com/docker/login-action), [setup-buildx](https://github.com/docker/setup-buildx-action)
and [setup-qemu](https://github.com/docker/setup-qemu-action)) that we have created. It's also rewritten as a
[typescript-action](https://github.com/actions/typescript-action/) to be as close as possible of the
[GitHub Runner](https://github.com/actions/virtual-environments) during its execution.
`v2` of this action includes significant updates and now uses Docker [Buildx](https://github.com/docker/buildx). It's
also rewritten as a [typescript-action](https://github.com/actions/typescript-action/) to be as close as possible
of the [GitHub Runner](https://github.com/actions/virtual-environments) during its execution.
[Upgrade notes](UPGRADE.md) and many [usage examples](#usage) have been added to handle most use cases but `v1` is
still available through [`releases/v1` branch](https://github.com/docker/build-push-action/tree/releases/v1).
[Upgrade notes](UPGRADE.md) with many [usage examples](#advanced-usage) have been added to handle most use cases but
`v1` is still available through [`releases/v1` branch](https://github.com/docker/build-push-action/tree/releases/v1).
## About
GitHub Action to build and push Docker images with [Buildx](https://github.com/docker/buildx).
GitHub Action to build and push Docker images with [Buildx](https://github.com/docker/buildx) with full support of the
features provided by [Moby BuildKit](https://github.com/moby/buildkit) builder toolkit. This includes multi-platform
build, secrets, remote cache, etc. and different builder deployment/namespacing options.
> :bulb: See also:
> * [login](https://github.com/docker/login-action) action
@ -31,46 +31,58 @@ ___
* [Usage](#usage)
* [Git context](#git-context)
* [Path context](#path-context)
* [Isolated builders](#isolated-builders)
* [Multi-platform image](#multi-platform-image)
* [Advanced usage](#advanced-usage)
* [Push to multi-registries](#push-to-multi-registries)
* [Cache to registry](#cache-to-registry)
* [Local registry](#local-registry)
* [Export image to Docker](#export-image-to-docker)
* [Leverage GitHub cache](#leverage-github-cache)
* [Handle tags and labels](#handle-tags-and-labels)
* [Update DockerHub repo description](#update-dockerhub-repo-description)
* [Multi-platform image](docs/advanced/multi-platform.md)
* [Secrets](docs/advanced/secrets.md)
* [Isolated builders](docs/advanced/isolated-builders.md)
* [Push to multi-registries](docs/advanced/push-multi-registries.md)
* [Cache](docs/advanced/cache.md)
* [Registry cache](docs/advanced/cache.md#registry-cache)
* [GitHub cache](docs/advanced/cache.md#github-cache)
* [Local registry](docs/advanced/local-registry.md)
* [Export image to Docker](docs/advanced/export-docker.md)
* [Handle tags and labels](docs/advanced/tags-labels.md)
* [Update DockerHub repo description](docs/advanced/dockerhub-desc.md)
* [Customizing](#customizing)
* [inputs](#inputs)
* [outputs](#outputs)
* [Notes](#notes)
* [Multi-line secret value](#multi-line-secret-value)
* [Troubleshooting](#troubleshooting)
* [Keep up-to-date with GitHub Dependabot](#keep-up-to-date-with-github-dependabot)
* [Limitation](#limitation)
## Usage
This action uses our [setup-buildx](https://github.com/docker/setup-buildx-action) action that extends the
`docker build` command named [buildx](https://github.com/docker/buildx) with the full support of the features
provided by [Moby BuildKit](https://github.com/moby/buildkit) builder toolkit. This includes multi-arch build,
build-secrets, remote cache, etc. and different builder deployment/namespacing options.
By default, this action uses the [Git context](#git-context) so you don't need to use the
[`actions/checkout`](https://github.com/actions/checkout/) action to checkout the repository because this will be
done directly by buildkit. The git reference will be based on the [event that triggered your workflow](https://docs.github.com/en/actions/reference/events-that-trigger-workflows)
and will result in the following context: `https://github.com/<owner>/<repo>.git#<ref>`.
Be careful because **any file mutation in the steps that precede the build step will be ignored** since
the context is based on the git reference. However, you can use the [Path context](#path-context) using the
[`context` input](#inputs) alongside the [`actions/checkout`](https://github.com/actions/checkout/) action to remove
this restriction.
In the examples below we are using 3 other actions:
* [`setup-buildx`](https://github.com/docker/setup-buildx-action) action will create and boot a builder using by
default the `docker-container` [builder driver](https://github.com/docker/buildx#--driver-driver). This is
**not required but recommended** using it to be able to build multi-platform images, export cache, etc.
* [`setup-qemu`](https://github.com/docker/setup-qemu-action) action can be useful if you want
to add emulation support with QEMU to be able to build against more platforms.
* [`login`](https://github.com/docker/setup-qemu-action) action will take care to log in against a Docker registry.
### Git context
The default behavior of this action is to use the Git context invoked by your workflow.
(eg. `https://github.com/<owner>/<repo>.git#<ref>`)
```yaml
name: ci
on:
push:
branches: master
branches:
- 'master'
jobs:
main:
docker:
runs-on: ubuntu-latest
steps:
-
@ -92,17 +104,14 @@ jobs:
with:
push: true
tags: user/app:latest
build-args: |
arg1=value1
arg2=value2
-
name: Image digest
run: echo ${{ steps.docker_build.outputs.digest }}
```
Building from current repository automatically uses the [GitHub Token](https://help.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token)
as provided by `secrets` so it does not need to be passed. But if you want to authenticate against another private
repository, you have to use a secret named `GIT_AUTH_TOKEN` to be able to authenticate against it with buildx:
Building from the current repository automatically uses the [GitHub Token](https://help.github.com/en/actions/configuring-and-managing-workflows/authenticating-with-the-github_token)
so it does not need to be passed. If you want to authenticate against another private repository, you have to use
a [secret](docs/advanced/secrets.md) named `GIT_AUTH_TOKEN` to be able to authenticate against it with buildx:
```yaml
-
@ -117,23 +126,20 @@ repository, you have to use a secret named `GIT_AUTH_TOKEN` to be able to authen
```
> :warning: Subdir for Git context is not yet supported ([moby/buildkit#1684](https://github.com/moby/buildkit/issues/1684))
> but you can use the [path context](#path-context) in the meantime.
> More info: https://docs.docker.com/engine/reference/commandline/build/#git-repositories
> but you can use the [path context](#path-context) in the meantime. More info on [Docker docs website](https://docs.docker.com/engine/reference/commandline/build/#git-repositories).
### Path context
You can also use the `PATH` context alongside the [`actions/checkout`](https://github.com/actions/checkout/) action.
```yaml
name: ci
on:
push:
branches: master
branches:
- 'master'
jobs:
path-context:
docker:
runs-on: ubuntu-latest
steps:
-
@ -156,432 +162,23 @@ jobs:
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
platforms: linux/amd64,linux/arm64,linux/386
push: true
tags: user/app:latest
```
### Isolated builders
```yaml
name: ci
on:
push:
branches: master
jobs:
multi-builders:
runs-on: ubuntu-latest
steps:
-
uses: docker/setup-buildx-action@v1
id: builder1
-
uses: docker/setup-buildx-action@v1
id: builder2
-
name: Builder 1 name
run: echo ${{ steps.builder1.outputs.name }}
-
name: Builder 2 name
run: echo ${{ steps.builder2.outputs.name }}
-
name: Build against builder1
uses: docker/build-push-action@v2
with:
builder: ${{ steps.builder1.outputs.name }}
target: mytarget1
-
name: Build against builder2
uses: docker/build-push-action@v2
with:
builder: ${{ steps.builder2.outputs.name }}
target: mytarget2
```
### Multi-platform image
```yaml
name: ci
on:
push:
branches: master
jobs:
multi:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x
push: true
tags: |
user/app:latest
user/app:1.0.0
```
## Advanced usage
### Push to multi-registries
The following workflow will connect you to [DockerHub](https://github.com/docker/login-action#dockerhub)
and [GitHub Container Registry](https://github.com/docker/login-action#github-container-registry) and push the
image to these registries.
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
multi-registries:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Login to GitHub Container Registry
uses: docker/login-action@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.CR_PAT }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x
push: true
tags: |
user/app:latest
user/app:1.0.0
ghcr.io/user/app:latest
ghcr.io/user/app:1.0.0
```
</details>
### Cache to registry
You can import/export cache from a cache manifest or (special) image configuration on the registry.
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
registry-cache:
runs-on: ubuntu-latest
steps:
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
push: true
tags: user/app:latest
cache-from: type=registry,ref=user/app:latest
cache-to: type=inline
```
</details>
### Local registry
For testing purposes you may need to create a [local registry](https://hub.docker.com/_/registry) to push images into:
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
local-registry:
runs-on: ubuntu-latest
services:
registry:
image: registry:2
ports:
- 5000:5000
steps:
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
with:
driver-opts: network=host
-
name: Build and push to local registry
uses: docker/build-push-action@v2
with:
push: true
tags: localhost:5000/name/app:latest
-
name: Inspect
run: |
docker buildx imagetools inspect localhost:5000/name/app:latest
```
</details>
### Export image to Docker
You may want your build result to be available in the Docker client through `docker images` to be able to use it
in another step of your workflow:
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
export-docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Build
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
load: true
tags: myimage:latest
-
name: Inspect
run: |
docker image inspect myimage:latest
```
</details>
### Leverage GitHub cache
You can leverage [GitHub cache](https://docs.github.com/en/actions/configuring-and-managing-workflows/caching-dependencies-to-speed-up-workflows)
using [actions/cache](https://github.com/actions/cache) with this action:
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
github-cache:
runs-on: ubuntu-latest
steps:
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Cache Docker layers
uses: actions/cache@v2
with:
path: /tmp/.buildx-cache
key: ${{ runner.os }}-buildx-${{ github.sha }}
restore-keys: |
${{ runner.os }}-buildx-
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
push: true
tags: user/app:latest
cache-from: type=local,src=/tmp/.buildx-cache
cache-to: type=local,dest=/tmp/.buildx-cache
```
</details>
### Handle tags and labels
If you come from [`v1`](https://github.com/docker/build-push-action/tree/releases/v1#readme) and want an
"automatic" tag management and [OCI Image Format Specification](https://github.com/opencontainers/image-spec/blob/master/annotations.md)
for labels, you can do it in a dedicated step. The following workflow will use the [Docker meta action](https://github.com/crazy-max/ghaction-docker-meta)
to handle tags and labels based on GitHub actions events and Git metadata.
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
schedule:
- cron: '0 10 * * *' # everyday at 10am
push:
branches:
- '**'
tags:
- 'v*.*.*'
pull_request:
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Docker meta
id: docker_meta
uses: crazy-max/ghaction-docker-meta@v1
with:
images: name/app # list of Docker images to use as base name for tags
tag-sha: true # add git short SHA as Docker tag
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
if: github.event_name != 'pull_request'
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
id: docker_build
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
platforms: linux/amd64,linux/arm64,linux/386
push: ${{ github.event_name != 'pull_request' }}
tags: ${{ steps.docker_meta.outputs.tags }}
labels: ${{ steps.docker_meta.outputs.labels }}
```
</details>
### Update DockerHub repo description
You can update the [DockerHub repository description](https://docs.docker.com/docker-hub/repos/) using
a third-party action called [DockerHub Description](https://github.com/peter-evans/dockerhub-description)
with this action:
<details>
<summary><b>Show workflow</b></summary>
```yaml
name: ci
on:
push:
branches: master
jobs:
main:
runs-on: ubuntu-latest
steps:
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
push: true
tags: user/app:latest
-
name: Update repo description
uses: peter-evans/dockerhub-description@v2
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_PASSWORD }}
repository: user/app
```
</details>
* [Multi-platform image](docs/advanced/multi-platform.md)
* [Secrets](docs/advanced/secrets.md)
* [Isolated builders](docs/advanced/isolated-builders.md)
* [Push to multi-registries](docs/advanced/push-multi-registries.md)
* [Cache](docs/advanced/cache.md)
* [Registry cache](docs/advanced/cache.md#registry-cache)
* [GitHub cache](docs/advanced/cache.md#github-cache)
* [Local registry](docs/advanced/local-registry.md)
* [Export image to Docker](docs/advanced/export-docker.md)
* [Handle tags and labels](docs/advanced/tags-labels.md)
* [Update DockerHub repo description](docs/advanced/dockerhub-desc.md)
## Customizing
@ -631,38 +228,6 @@ Following outputs are available
|---------------|---------|---------------------------------------|
| `digest` | String | Image content-addressable identifier also called a digest |
## Notes
### Multi-line secret value
To handle multi-line value for a secret, you will need to place the key-value pair between quotes:
```yaml
secrets: |
"MYSECRET=${{ secrets.GPG_KEY }}"
GIT_AUTH_TOKEN=abcdefghi,jklmno=0123456789
"MYSECRET=aaaaaaaa
bbbbbbb
ccccccccc"
FOO=bar
"EMPTYLINE=aaaa
bbbb
ccc"
"JSON_SECRET={""key1"":""value1"",""key2"":""value2""}"
```
| Key | Value |
|--------------------|--------------------------------------------------|
| `MYSECRET` | `***********************` |
| `GIT_AUTH_TOKEN` | `abcdefghi,jklmno=0123456789` |
| `MYSECRET` | `aaaaaaaa\nbbbbbbb\nccccccccc` |
| `FOO` | `bar` |
| `EMPTYLINE` | `aaaa\n\nbbbb\nccc` |
| `JSON_SECRET` | `{"key1":"value1","key2":"value2"}` |
> Note: all quote signs need to be doubled for escaping.
## Troubleshooting
See [TROUBLESHOOTING.md](TROUBLESHOOTING.md)

@ -59,8 +59,7 @@ jobs:
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64,linux/ppc64le,linux/s390x
platforms: linux/amd64,linux/arm64
tags: docker.io/user/app:latest
outputs: type=oci,dest=/tmp/image.tar
-

@ -63,7 +63,6 @@ steps:
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
pull: true
push: true
build-args: |
@ -136,7 +135,6 @@ steps:
uses: docker/build-push-action@v2
with:
context: .
file: ./Dockerfile
push: ${{ github.event_name != 'pull_request' }}
tags: ${{ steps.prep.outputs.tags }}
labels: |
@ -145,5 +143,5 @@ steps:
org.opencontainers.image.revision=${{ github.sha }}
```
> You can also use the [Docker meta action](https://github.com/crazy-max/ghaction-docker-meta) to handle tags and
> labels based on GitHub actions events and Git metadata. A workflow example is available in the [README](README.md#handle-tags-and-labels).
> You can also use the [Docker meta action to handle tags and labels](docs/advanced/tags-labels.md) based on GitHub
> actions events and Git metadata.

107
docs/advanced/cache.md Normal file

@ -0,0 +1,107 @@
# Cache
* [Registry cache](#registry-cache)
* [GitHub cache](#github-cache)
> More info about buildx cache: https://github.com/docker/buildx#--cache-fromnametypetypekeyvalue
## Registry cache
You can import/export cache from a cache manifest or (special) image configuration on the registry.
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
push: true
tags: user/app:latest
cache-from: type=registry,ref=user/app:latest
cache-to: type=inline
```
## GitHub cache
> :warning: At the moment caches are copied over the existing cache so it [keeps growing](https://github.com/docker/build-push-action/issues/252).
> The `Move cache` step is used as a temporary fix (see https://github.com/moby/buildkit/issues/1896).
> :rocket: There is a new cache backend using GitHub cache being developed that will lighten your workflow.
> More info: https://github.com/docker/buildx/pull/535
You can leverage [GitHub cache](https://docs.github.com/en/actions/configuring-and-managing-workflows/caching-dependencies-to-speed-up-workflows)
using [actions/cache](https://github.com/actions/cache) with this action:
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Cache Docker layers
uses: actions/cache@v2
with:
path: /tmp/.buildx-cache
key: ${{ runner.os }}-buildx-${{ github.sha }}
restore-keys: |
${{ runner.os }}-buildx-
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
push: true
tags: user/app:latest
cache-from: type=local,src=/tmp/.buildx-cache
cache-to: type=local,dest=/tmp/.buildx-cache-new
-
# Temp fix
# https://github.com/docker/build-push-action/issues/252
# https://github.com/moby/buildkit/issues/1896
name: Move cache
run: |
rm -rf /tmp/.buildx-cache
mv /tmp/.buildx-cache-new /tmp/.buildx-cache
```

@ -0,0 +1,48 @@
# Update DockerHub repo description
You can update the [DockerHub repository description](https://docs.docker.com/docker-hub/repos/) using
a third party action called [DockerHub Description](https://github.com/peter-evans/dockerhub-description)
with this action:
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
push: true
tags: user/app:latest
-
name: Update repo description
uses: peter-evans/dockerhub-description@v2
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_PASSWORD }}
repository: user/app
```

@ -0,0 +1,35 @@
# Export image to Docker
You may want your build result to be available in the Docker client through `docker images` to be able to use it
in another step of your workflow:
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Build
uses: docker/build-push-action@v2
with:
context: .
load: true
tags: myimage:latest
-
name: Inspect
run: |
docker image inspect myimage:latest
```

@ -0,0 +1,44 @@
# Isolated builders
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
uses: docker/setup-buildx-action@v1
id: builder1
-
uses: docker/setup-buildx-action@v1
id: builder2
-
name: Builder 1 name
run: echo ${{ steps.builder1.outputs.name }}
-
name: Builder 2 name
run: echo ${{ steps.builder2.outputs.name }}
-
name: Build against builder1
uses: docker/build-push-action@v2
with:
builder: ${{ steps.builder1.outputs.name }}
context: .
target: mytarget1
-
name: Build against builder2
uses: docker/build-push-action@v2
with:
builder: ${{ steps.builder2.outputs.name }}
context: .
target: mytarget2
```

@ -0,0 +1,44 @@
# Local registry
For testing purposes you may need to create a [local registry](https://hub.docker.com/_/registry) to push images into:
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
services:
registry:
image: registry:2
ports:
- 5000:5000
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
with:
driver-opts: network=host
-
name: Build and push to local registry
uses: docker/build-push-action@v2
with:
context: .
push: true
tags: localhost:5000/name/app:latest
-
name: Inspect
run: |
docker buildx imagetools inspect localhost:5000/name/app:latest
```

@ -0,0 +1,44 @@
# Multi-platform image
You can build multi-platform images using the [`platforms` input](../../README.md#inputs) as described below.
> :bulb: List of available platforms will be displayed and available through our [setup-buildx](https://github.com/docker/setup-buildx-action#about) action.
> :bulb: If you want support for more platforms, you can use QEMU with our [setup-qemu](https://github.com/docker/setup-qemu-action) action.
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
platforms: linux/amd64,linux/arm64
push: true
tags: user/app:latest
```

@ -0,0 +1,57 @@
# Push to multi-registries
* [Docker Hub and GHCR](#docker-hub-and-ghcr)
## Docker Hub and GHCR
The following workflow will connect you to [DockerHub](https://github.com/docker/login-action#dockerhub)
and [GitHub Container Registry](https://github.com/docker/login-action#github-container-registry) and push the
image to these registries.
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Login to GitHub Container Registry
uses: docker/login-action@v1
with:
registry: ghcr.io
username: ${{ github.repository_owner }}
password: ${{ secrets.CR_PAT }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
platforms: linux/amd64,linux/arm64
push: true
tags: |
user/app:latest
user/app:1.0.0
ghcr.io/user/app:latest
ghcr.io/user/app:1.0.0
```

84
docs/advanced/secrets.md Normal file

@ -0,0 +1,84 @@
# Secrets
In the following example we will expose and use the [GITHUB_TOKEN secret](https://docs.github.com/en/actions/reference/authentication-in-a-workflow#about-the-github_token-secret)
as provided by GitHub in your workflow.
First let's create our `Dockerfile` to use our secret:
```Dockerfile
#syntax=docker/dockerfile:1.2
FROM alpine
RUN --mount=type=secret,id=github_token \
cat /run/secrets/github_token
```
As you can see we have named our secret `github_token`. Here is the workflow you can use to expose this secret using
the [`secrets` input](../../README.md#inputs):
```yaml
name: ci
on:
push:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Build
uses: docker/build-push-action@v2
with:
context: .
platforms: linux/amd64,linux/arm64
tags: user/app:latest
secrets: |
"github_token=${{ secrets.GITHUB_TOKEN }}"
```
> :bulb: You can also expose a secret file to the build with [`secret-files`](../../README.md#inputs) input:
> ```yaml
> secret-files: |
> "MY_SECRET=./secret.txt"
> ```
If you're using [GitHub secrets](https://docs.github.com/en/actions/reference/encrypted-secrets) and need to handle
multi-line value, you will need to place the key-value pair between quotes:
```yaml
secrets: |
"MYSECRET=${{ secrets.GPG_KEY }}"
GIT_AUTH_TOKEN=abcdefghi,jklmno=0123456789
"MYSECRET=aaaaaaaa
bbbbbbb
ccccccccc"
FOO=bar
"EMPTYLINE=aaaa
bbbb
ccc"
"JSON_SECRET={""key1"":""value1"",""key2"":""value2""}"
```
| Key | Value |
|--------------------|--------------------------------------------------|
| `MYSECRET` | `***********************` |
| `GIT_AUTH_TOKEN` | `abcdefghi,jklmno=0123456789` |
| `MYSECRET` | `aaaaaaaa\nbbbbbbb\nccccccccc` |
| `FOO` | `bar` |
| `EMPTYLINE` | `aaaa\n\nbbbb\nccc` |
| `JSON_SECRET` | `{"key1":"value1","key2":"value2"}` |
> :bulb: All quote signs need to be doubled for escaping.

@ -0,0 +1,70 @@
# Handle tags and labels
If you come from [`v1`](https://github.com/docker/build-push-action/tree/releases/v1#readme) and want an
"automatic" tag management and [OCI Image Format Specification](https://github.com/opencontainers/image-spec/blob/master/annotations.md)
for labels, you can do it in a dedicated step. The following workflow will use the [Docker meta action](https://github.com/crazy-max/ghaction-docker-meta)
to handle tags and labels based on GitHub actions events and Git metadata.
```yaml
name: ci
on:
schedule:
- cron: '0 10 * * *' # everyday at 10am
push:
branches:
- '**'
tags:
- 'v*.*.*'
pull_request:
branches:
- 'master'
jobs:
docker:
runs-on: ubuntu-latest
steps:
-
name: Checkout
uses: actions/checkout@v2
-
name: Docker meta
id: docker_meta
uses: crazy-max/ghaction-docker-meta@v1
with:
# list of Docker images to use as base name for tags
images: |
name/app
ghcr.io/username/app
# add git short SHA as Docker tag
tag-sha: true
-
name: Set up QEMU
uses: docker/setup-qemu-action@v1
-
name: Set up Docker Buildx
uses: docker/setup-buildx-action@v1
-
name: Login to DockerHub
if: github.event_name != 'pull_request'
uses: docker/login-action@v1
with:
username: ${{ secrets.DOCKERHUB_USERNAME }}
password: ${{ secrets.DOCKERHUB_TOKEN }}
-
name: Login to GHCR
if: github.event_name != 'pull_request'
uses: docker/login-action@v1
with:
registry: ghcr.io
username: ${{ secrets.GHCR_USERNAME }}
password: ${{ secrets.GHCR_TOKEN }}
-
name: Build and push
uses: docker/build-push-action@v2
with:
context: .
push: ${{ github.event_name != 'pull_request' }}
tags: ${{ steps.docker_meta.outputs.tags }}
labels: ${{ steps.docker_meta.outputs.labels }}
```