CNB Auto Docker Tag Plugin - Automatically manage Docker image tag version numbers.

• Automatically fetch all tags of a Docker image, sorted by version number
• Intelligent version increment (supports custom rules)
• Support multiple tag format templates
• Output pipeline variables for subsequent steps

The plugin supports the following tag format templates:

tagFormat: "v@{version}"

Examples: v1.0.1, v1.0.2, v1.1.0

Version increment rules:

• If the image has no tags, generate initial version v1.0.1
• Otherwise, get the latest tag (sorted by semantic version), increment rules:
  • Patch number increases by 1
  • If patch reaches 100, carry to minor version and reset patch to 0
  • If minor reaches 100, carry to major version and reset minor and patch to 0

Examples:

• v1.0.1 → v1.0.2
• v1.0.99 → v1.1.0
• v1.99.99 → v2.0.0

tagFormat: "v@{auto}"

Examples: v1, v2, v3

Version increment rules:

• If the image has no tags, generate initial version v1
• Otherwise, get the latest tag's number and add 1

tagFormat: "@{yyyyMMdd}-v@{version}"

Examples: 20260325-v1.0.1

tagFormat: "@{yyyyMMdd}-v@{auto}"

Examples: 20260325-v1

Date handling rules:

• @{yyyyMMdd} will be replaced with the current date (e.g., 20260325)
• Preferentially select the latest version of the day for incrementing
• If there is no version for the day, create a new version

Use in .cnb.yml pipeline configuration:

stages:
  - name: auto-docker-tag
    image: docker.cnb.cool/r_r/auto-docker-tag:latest
    settings:
      tagFormat: "v@{version}"

• Type: string
• Default: Current repository path (environment variable CNB_REPO_SLUG_LOWERCASE)
• Required: Yes
• Description: Repository path. Not needed for same-repo operations, specify this parameter for cross-repo operations.

Example:

stages:
  - name: auto-docker-tag
    image: docker.cnb.cool/r_r/auto-docker-tag:latest
    settings:
      slug: "other-owner/other-repo"

• Type: string
• Default: docker
• Required: Yes
• Description: Package type. Currently only supports docker.

• Type: string
• Default: Current repository path (environment variable CNB_REPO_SLUG_LOWERCASE)
• Required: Yes
• Description: Docker image name. Defaults to the same as slug, can be specified separately.

Example:

stages:
  - name: auto-docker-tag
    image: docker.cnb.cool/r_r/auto-docker-tag:latest
    settings:
      imageName: "my-custom-image"

• Type: string
• Default: v@{version}
• Required: No
• Description: Specify tag format, supports @{version}, @{auto}, @{yyyyMMdd} placeholders.

Example:

stages:
  - name: auto-docker-tag
    image: docker.cnb.cool/r_r/auto-docker-tag:latest
    settings:
      tagFormat: "@{yyyyMMdd}-v@{version}"

• Type: string
• Default: Current platform's OPENAPI address (environment variable CNB_API_ENDPOINT)
• Required: No
• Description: Platform API address. Not needed for same-platform operations, specify this parameter for cross-platform operations, e.g., https://api.cnb.cool.

• Type: string
• Default: Current user's temporary token (environment variable CNB_TOKEN)
• Required: No
• Description: Platform token. Can be passed for cross-platform creation. Requires registry-related permissions.

The following pipeline variables will be output:

##[set-output auto-docker-tag=v1.0.1]
##[set-output auto-docker-tag-url=docker.cnb.cool/h_h/images/aws-freetier-monitor:v1.0.1]

main:
  push:
    - stages:
        - name: auto-docker-tag
          image: docker.cnb.cool/r_r/auto-docker-tag:latest
          settings:
            tagFormat: "v@{version}"
            auto-docker-tag: DOCKER_TAG
            auto-docker-tag-url: DOCKER_TAG_URL
        - name: echo env
          script:
            - echo "DOCKER_TAG $DOCKER_TAG"
            - echo "DOCKER_TAG_URL $DOCKER_TAG_URL"

main:
  push:
    - stages:
        - name: auto-docker-tag
          image: docker.cnb.cool/r_r/auto-docker-tag:latest
          settings:
            tagFormat: "@{yyyyMMdd}-v@{auto}"

main:
  push:
    - stages:
        - name: auto-docker-tag-other-repo
          image: docker.cnb.cool/r_r/auto-docker-tag:latest
          settings:
            slug: "other-owner/other-repo"
            imageName: "my-image"
            endpoint: "https://api.cnb.cool"
            token: "${OTHER_REPO_TOKEN}"

The plugin will exit with a non-zero status code, causing the pipeline to fail, in the following cases:

• Missing parameters (token, endpoint, slug, imageName, type)
• API call failure
• Image not found

MIT License