fetch-dockerhub-tags

Fetch Docker Hub tags for a specific image.

Why?

Ever build some custom image that depends on a base image that is frequently updated? This action can help you automatically fetch the latest tag for that base image, ensuring your builds are always up-to-date.

Inputs

Input	Required	Default	Example	Description
repo	Yes		library/nginx	Docker Hub repository to fetch tags from.
filter	No		main	Optional RegEx filter to apply when fetching tags.
max_pages	No	1	-1	Maximum number of Docker Hub tag pages to fetch; -1 = all.
token	No			Optional token to authenticate with Docker Hub.

Outputs

• name: Resolved Docker image tag for the selected repository.
• full_size: Size of the Docker image.
• architecture: Architecture(s) of the Docker image (comma-separated if multiple).
• last_updated: Timestamp of when the image was last updated.
• digest: Digest of the Docker image.
• matched-groups: JSON array of RegEx capture groups from the selected tag.
• results: JSON array of all fetched tags with their details.

Examples

Basic usage:

- name: 🔎 Fetch Docker Hub Tags
  uses: nerd-coder/fetch-dockerhub-tags@v1
  with:
    repo: library/nginx

With filter and token:

- name: 🔎 Fetch Docker Hub Tags
  uses: nerd-coder/fetch-dockerhub-tags@v1
  with:
    repo: library/nginx
    filter: ^\d+\.\d+\.debian13$ # RegEx to match tags like "1.21.6-debian13"
    max_pages: -1 # Fetch all pages when the match may not be on the first page
    token: ${{ secrets.DOCKERHUB_TOKEN }}

Example output:

name: 1.21.6-debian13
full_size: 133MB
architecture: amd64, arm64
last_updated: 2024-06-01T12:00:00Z
digest: sha256:abc123def456...
matched-groups: '["1.21.6"]'
results: '[{"name":"1.21.6-debian13","full_size":133000000,"architecture":["amd64","arm64"],"last_updated":"2024-06-01T12:00:00Z","digest":"sha256:abc123def456...","matched_groups":["1.21.6"]}, ...]'

Acknowledgments

This action uses the Docker Hub API to fetch tags. For more details on the API, please refer to the official documentation:

🌐 https://docs.docker.com/reference/api/hub/latest/

License

This project is licensed under the Apache License 2.0.