metadata-action/README.md at 4a03258546d99c816e54617e93681f3c6b489aaf

mirror of https://github.com/docker/metadata-action.git synced 2024-11-08 21:25:40 +01:00

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

2021-05-22 21:23:06 +02:00

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About

GitHub Action to extract metadata (tags, labels) for Docker. This action is particularly useful if used with Docker Build Push action.

Usage
Customizing
- inputs
- outputs
flavor input
tags input
Notes
Keep up-to-date with GitHub Dependabot

Usage

Basic

name: ci

on:
  push:
    branches:
      - 'master'
    tags:
      - 'v*'
  pull_request:
    branches:
      - 'master'

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v2
      -
        name: Docker meta
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: name/app
      -
        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
        uses: docker/build-push-action@v2
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

Event	Ref	Docker Tags
`pull_request`	`refs/pull/2/merge`	`pr-2`
`push`	`refs/heads/master`	`master`
`push`	`refs/heads/releases/v1`	`releases-v1`
`push tag`	`refs/tags/v1.2.3`	`v1.2.3`, `latest`
`push tag`	`refs/tags/v2.0.8-beta.67`	`v2.0.8-beta.67`, `latest`

Semver

name: ci

on:
  push:
    branches:
      - 'master'
    tags:
      - 'v*'
  pull_request:
    branches:
      - 'master'

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v2
      -
        name: Docker meta
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: name/app
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}            
      -
        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
        uses: docker/build-push-action@v2
        with:
          context: .
          push: ${{ github.event_name != 'pull_request' }}
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}

Event	Ref	Docker Tags
`pull_request`	`refs/pull/2/merge`	`pr-2`
`push`	`refs/heads/master`	`master`
`push`	`refs/heads/releases/v1`	`releases-v1`
`push tag`	`refs/tags/v1.2.3`	`1.2.3`, `1.2`, `latest`
`push tag`	`refs/tags/v2.0.8-beta.67`	`2.0.8-beta.67`

Bake definition

This action also handles a bake definition file that can be used with the Docker Bake action. You just have to declare an empty target named docker-metadata-action and inherit from it.

// docker-bake.hcl
target "docker-metadata-action" {}

target "build" {
  inherits = ["docker-metadata-action"]
  context = "./"
  dockerfile = "Dockerfile"
  platforms = ["linux/amd64", "linux/arm/v6", "linux/arm/v7", "linux/arm64", "linux/386", "linux/ppc64le"]
}

name: ci

on:
  push:
    branches:
      - 'master'
    tags:
      - 'v*'

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v2
      -
        name: Docker meta
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: name/app
          tags: |
            type=ref,event=branch
            type=ref,event=pr
            type=semver,pattern={{version}}
            type=semver,pattern={{major}}.{{minor}}
            type=sha            
      -
        name: Build
        uses: docker/bake-action@v1
        with:
          files: |
            ./docker-bake.hcl
            ${{ steps.meta.outputs.bake-file }}            
          targets: build

Content of ${{ steps.meta.outputs.bake-file }} file will look like this with refs/tags/v1.2.3 ref:

{
  "target": {
    "docker-metadata-action": {
      "tags": [
        "name/app:1.2.3",
        "name/app:1.2",
        "name/app:sha-90dd603",
        "name/app:latest"
      ],
      "labels": {
        "org.opencontainers.image.title": "Hello-World",
        "org.opencontainers.image.description": "This your first repo!",
        "org.opencontainers.image.url": "https://github.com/octocat/Hello-World",
        "org.opencontainers.image.source": "https://github.com/octocat/Hello-World",
        "org.opencontainers.image.version": "1.2.3",
        "org.opencontainers.image.created": "2020-01-10T00:30:00.000Z",
        "org.opencontainers.image.revision": "90dd6032fac8bda1b6c4436a2e65de27961ed071",
        "org.opencontainers.image.licenses": "MIT"
      },
      "args": {
        "DOCKER_META_IMAGES": "name/app",
        "DOCKER_META_VERSION": "1.2.3"
      }
    }
  }
}

Customizing

inputs

Following inputs can be used as step.with keys

List type is a newline-delimited string

labels: |
  org.opencontainers.image.title=MyCustomTitle
  org.opencontainers.image.description=Another description
  org.opencontainers.image.vendor=MyCompany

CSV type is a comma-delimited string
images: name/app,ghcr.io/name/app

Name	Type	Description
`images`	List/CSV	List of Docker images to use as base name for tags
`tags`	List	List of tags as key-value pair attributes
`flavor`	List	Flavor to apply
`labels`	List	List of custom labels
`sep-tags`	String	Separator to use for tags output (default `\n`)
`sep-labels`	String	Separator to use for labels output (default `\n`)
`bake-target`	String	Bake target name (default `docker-metadata-action`)

outputs

Following outputs are available

Name	Type	Description
`version`	String	Docker image version
`tags`	String	Docker tags
`labels`	String	Docker labels
`json`	String	JSON output of tags and labels
`bake-file`	File	Bake definition file path

`flavor` input

flavor defines a global behavior for tags:

flavor: |
  latest=auto
  prefix=
  suffix=

latest=<auto|true|false>: Handle latest tag (default auto)
prefix=<string>: A global prefix for each generated tag
suffix=<string>: A global suffix for each generated tag

`tags` input

tags is the core input of this action as everything related to it will reflect the output metadata. This one is in the form of a key-value pair list in CSV format to remove limitations intrinsically linked to GitHub Actions (only string format is handled in the input fields). Here is an example:

tags: |
  type=schedule
  type=ref,event=branch
  type=ref,event=pr
  type=semver,pattern={{version}}
  type=semver,pattern={{major}}.{{minor}}
  type=semver,pattern={{major}}
  type=sha

Each entry is defined by a type, which are:

type=schedule
type=semver
type=match
type=edge
type=ref
type=raw
type=sha

And global attributes:

enable=<true|false> enable this entry (default true)
priority=<number> priority to manage the order of tags
prefix=<string> add prefix
suffix=<string> add suffix

Default entries if tags input is empty:

tags: |
  type=schedule
  type=ref,event=branch
  type=ref,event=tag
  type=ref,event=pr

`type=schedule`

tags: |
  # minimal
  type=schedule
  # default
  type=schedule,pattern=nightly
  # handlebars
  type=schedule,pattern={{date 'YYYYMMDD'}}

Will be used on schedule event.

pattern is a specially crafted attribute to support Handlebars template with the following expressions:

date 'format' ; render date by its moment format

Pattern	Output
`nightly`	`nightly`
`{{date 'YYYYMMDD'}}`	`20210326`

Extended attributes and default values:

tags: |
  type=schedule,enable=true,priority=1000,prefix=,suffix=,pattern=nightly

`type=semver`

tags: |
  # minimal
  type=semver,pattern={{version}}
  # use custom value instead of git tag
  type=semver,pattern={{version}},value=v1.0.0

Will be used on a push tag event and requires a valid Git tag semver but you can also use a custom value through value attribute.

pattern attribute supports Handlebars template with the following expressions:

raw ; the actual semver
version ; shorthand for {{major}}.{{minor}}.{{patch}} (can include pre-release)
major ; major version identifier
minor ; minor version identifier
patch ; patch version identifier

Git tag	Pattern	Output
`v1.2.3`	`{{raw}}`	`v1.2.3`
`v1.2.3`	`{{version}}`	`1.2.3`
`v1.2.3`	`{{major}}.{{minor}}`	`1.2`
`v1.2.3`	`v{{major}}`	`v1`
`v1.2.3`	`{{minor}}`	`2`
`v1.2.3`	`{{patch}}`	`3`
`v2.0.8-beta.67`	`{{raw}}`	`2.0.8-beta.67`*
`v2.0.8-beta.67`	`{{version}}`	`2.0.8-beta.67`
`v2.0.8-beta.67`	`{{major}}.{{minor}}`	`2.0.8-beta.67`*

*Pre-release (rc, beta, alpha) will only extend {{version}} as tag because they are updated frequently, and contain many breaking changes that are (by the author's design) not yet fit for public consumption.

Extended attributes and default values:

tags: |
  type=semver,enable=true,priority=900,prefix=,suffix=,pattern=,value=

`type=match`

tags: |
  # minimal
  type=match,pattern=\d.\d.\d
  # define match group
  type=match,pattern=v(.*),group=1
  # use custom value instead of git tag
  type=match,pattern=v(.*),group=1,value=v1.0.0

Can create a regular expression for matching Git tag with a pattern and capturing group. Will be used on a push tag event but you can also use a custom value through value attribute.

Git tag	Pattern	Group	Output
`v1.2.3`	`\d.\d.\d`	`0`	`1.2.3`
`v2.0.8-beta.67`	`v(.*)`	`1`	`2.0.8-beta.67`
`v2.0.8-beta.67`	`v(\d.\d)`	`1`	`2.0`
`20200110-RC2`	`\d+`	`0`	`20200110`
`p1/v1.2.3`	`p1-v(\d.\d.\d)`	`1`	`1.2.3`

Extended attributes and default values:

tags: |
  type=match,enable=true,priority=800,prefix=,suffix=,pattern=,group=0,value=

`type=edge`

tags: |
  # minimal
  type=edge
  # define default branch
  type=edge,branch=main

An edge tag reflects the last commit of the active branch on your Git repository. I usually prefer to use edge as a Docker tag for a better distinction or common pattern. This is also used by official images like Alpine.

Extended attributes and default values:

tags: |
  type=edge,enable=true,priority=700,prefix=,suffix=,branch=$repo.default_branch

`type=ref`

tags: |
  # branch event
  type=ref,event=branch
  # tag event
  type=ref,event=tag
  # pull request event
  type=ref,event=pr

This type handles Git ref (or reference) for the following events:

branch ; eg. refs/heads/master
tag ; eg. refs/tags/v1.0.0
pr ; eg. refs/pull/318/merge

Event	Ref	Output
`pull_request`	`refs/pull/2/merge`	`pr-2`
`push`	`refs/heads/master`	`master`
`push`	`refs/heads/my/branch`	`my-branch`
`push tag`	`refs/tags/v1.2.3`	`v1.2.3`
`push tag`	`refs/tags/v2.0.8-beta.67`	`v2.0.8-beta.67`

Extended attributes and default values:

tags: |
  # branch event
  type=ref,enable=true,priority=600,prefix=,suffix=,event=
  # tag event
  type=ref,enable=true,priority=600,prefix=,suffix=,event=
  # pull request event
  type=ref,enable=true,priority=600,prefix=pr-,suffix=,event=

`type=raw`

tags: |
  type=raw,value=foo
  type=raw,value=bar
  # or
  type=raw,foo
  type=raw,bar
  # or
  foo
  bar

Output custom tags according to your needs.

Extended attributes and default values:

tags: |
  type=raw,enable=true,priority=200,prefix=,suffix=,value=

`type=sha`

tags: |
  # minimal (short sha)
  type=sha
  # full length sha
  type=sha,format=long

Output Git short commit (or long if specified) as Docker tag like sha-ad132f5.

Extended attributes and default values:

tags: |
  type=sha,enable=true,priority=100,prefix=sha-,suffix=,format=short

Notes

Latest tag

latest tag is handled through the flavor input. It will be generated by default (auto mode) for:

type=ref,event=tag
type=semver,pattern=...
type=match,pattern=...

Global expressions

The following Handlebars template expressions for prefix, suffix and value attributes are available:

Expression	Output
`{{branch}}`	`master`
`{{tag}}`	`v1.2.3`
`{{sha}}`	`90dd603`

tags: |
  # dynamically set the branch name as a prefix
  type=sha,prefix={{branch}}-
  # dynamically set the branch name and sha as a custom tag
  type=raw,value=mytag-{{branch}}-{{sha}}

Major version zero

Major version zero (0.y.z) is for initial development and may change at any time. This means the public API should not be considered stable.

In this case, Docker tag 0 should not be generated if you're using type=semver with {{major}} pattern. You can manage this behavior like this:

# refs/tags/v0.1.2
tags: |
  # output 0.1.2
  type=semver,pattern={{version}}
  # output 0.1
  type=semver,pattern={{major}}.{{minor}}
  # disabled if major zero
  type=semver,pattern={{major}},enable=${{ !startsWith(github.ref, 'refs/tags/v0.') }}

JSON output object

The json output is a JSON object composed of the generated tags and labels so that you can reuse them further in your workflow using the fromJSON function:

      -
        name: Docker meta
        uses: docker/metadata-action@v3
        id: meta
        with:
          images: name/app
      -
        name: Build and push
        uses: docker/build-push-action@v2
        with:
          tags: ${{ steps.meta.outputs.tags }}
          labels: ${{ steps.meta.outputs.labels }}
          build-args: |
            BUILDTIME=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.created'] }}
            VERSION=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.version'] }}
            REVISION=${{ fromJSON(steps.meta.outputs.json).labels['org.opencontainers.image.revision'] }}

Overwrite labels

If some of the OCI Image Format Specification labels generated are not suitable, you can overwrite them like this:

      -
        name: Docker meta
        id: meta
        uses: docker/metadata-action@v3
        with:
          images: name/app
          labels: |
            maintainer=CrazyMax
            org.opencontainers.image.title=MyCustomTitle
            org.opencontainers.image.description=Another description
            org.opencontainers.image.vendor=MyCompany

Keep up-to-date with GitHub Dependabot

Since Dependabot has native GitHub Actions support, to enable it on your GitHub repo all you need to do is add the .github/dependabot.yml file:

version: 2
updates:
  # Maintain dependencies for GitHub Actions
  - package-ecosystem: "github-actions"
    directory: "/"
    schedule:
      interval: "daily"

20 KiB Raw Blame History

About

Usage

Basic

Semver

Bake definition

Customizing

inputs

outputs

flavor input

tags input

type=schedule

type=semver

type=match

type=edge

type=ref

type=raw

type=sha

Notes

Latest tag

Global expressions

Major version zero

JSON output object

Overwrite labels

Keep up-to-date with GitHub Dependabot

20 KiB

Raw Blame History

`flavor` input

`tags` input

`type=schedule`

`type=semver`

`type=match`

`type=edge`

`type=ref`

`type=raw`

`type=sha`