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content/manuals/build/ci/github-actions/annotations.md
d1b820b1c3550f49575c8977b07ed034b2d1b06629059c7a0000000300001059
---
title: Add image annotations with GitHub Actions
linkTitle: Annotations
description: Add OCI annotations to image components using GitHub Actions
keywords: ci, github actions, gha, buildkit, buildx, annotations, oci
---

Annotations let you specify arbitrary metadata for OCI image components, such
as manifests, indexes, and descriptors.

To add annotations when building images with GitHub Actions, use the
[metadata-action] to automatically create OCI-compliant annotations. The
metadata action creates an `annotations` output that you can reference, both
with [build-push-action] and [bake-action].


{{< tabs >}}
{{< tab name="build-push-action" >}}

```yaml {hl_lines=32}
name: ci

on:
  push:

env:
  IMAGE_NAME: user/app

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}

      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.IMAGE_NAME }}

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          tags: ${{ steps.meta.outputs.tags }}
          annotations: ${{ steps.meta.outputs.annotations }}
          push: true
```

{{< /tab >}}
{{< tab name="bake-action" >}}

```yaml {hl_lines=37}
name: ci

on:
  push:

env:
  IMAGE_NAME: user/app

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.IMAGE_NAME }}

      - name: Build
        uses: docker/bake-action@v6
        with:
          files: |
            ./docker-bake.hcl
            cwd://${{ steps.meta.outputs.bake-file-tags }}
            cwd://${{ steps.meta.outputs.bake-file-annotations }}
          push: true
```

{{< /tab >}}
{{< /tabs >}}

## Configure annotation level

By default, annotations are placed on image manifests. To configure the
[annotation level](../../metadata/annotations.md#specify-annotation-level), set
the `DOCKER_METADATA_ANNOTATIONS_LEVELS` environment variable on the
`metadata-action` step to a comma-separated list of all the levels that you
want to annotate. For example, setting `DOCKER_METADATA_ANNOTATIONS_LEVELS` to
`index` results in annotations on the image index instead of the manifests.

The following example creates annotations on both the image index and
manifests.

```yaml {hl_lines=28}
name: ci

on:
  push:

env:
  IMAGE_NAME: user/app

jobs:
  docker:
    runs-on: ubuntu-latest
    steps:
      - name: Login to Docker Hub
        uses: docker/login-action@v3
        with:
          username: ${{ vars.DOCKERHUB_USERNAME }}
          password: ${{ secrets.DOCKERHUB_TOKEN }}
      
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Extract metadata
        id: meta
        uses: docker/metadata-action@v5
        with:
          images: ${{ env.IMAGE_NAME }}
        env:
          DOCKER_METADATA_ANNOTATIONS_LEVELS: manifest,index

      - name: Build and push
        uses: docker/build-push-action@v6
        with:
          tags: ${{ steps.meta.outputs.tags }}
          annotations: ${{ steps.meta.outputs.annotations }}
          push: true
```

> [!NOTE]
>
> The build must produce the components that you want to annotate. For example,
> to annotate an image index, the build must produce an index. If the build
> produces only a manifest and you specify `index` or `index-descriptor`, the
> build fails.

Chunks
1ee9ea1a (1st chunk of `content/manuals/build/ci/github-actions/annotations.md`)
Title: Adding OCI Image Annotations with GitHub Actions
Summary
This document explains how to add OCI annotations to image components using GitHub Actions. It describes using the `metadata-action` to create OCI-compliant annotations, which can then be referenced with `build-push-action` or `bake-action`. It also covers configuring the annotation level to specify where annotations are placed (e.g., image manifests or indexes) by setting the `DOCKER_METADATA_ANNOTATIONS_LEVELS` environment variable.