CheckMarketplaceMetadata

The CheckMarketplaceMetadata job template validates an action’s metadata file against the rules GitHub Marketplace applies when an action is listed.

The Marketplace checks this metadata only at publish time, in a web form, and rejects it without much explanation. This template applies the same rules on every push, so a defect is a red pipeline on the development branch rather than a rejection months later.

Note

Publishing itself is not automated, because there is no API for it: an action is listed by ticking Publish this Action to the GitHub Marketplace while drafting or editing its release.

A tag carries exactly one release, and the Marketplace listing is a property of that release rather than a second one - so an already-published release is edited, not re-created. Drafting a new release for a tag that has one fails with “Duplicate tag name - This tag already has release notes.”

Features

• Check that the action metadata file exists at the repository root.

• Check the action’s name, description length, branding icon and branding colour.

• Check that the repository is public.

Behavior

1. Check that action_file exists. If it doesn’t, the job fails immediately - there is nothing else to check.

2. Read name, description and branding with a YAML parser, so a folded or quoted value is measured as the Marketplace measures it.

3. Report every violated rule, then fail if any was found:

   • name is missing,

   • description is missing, or is not shorter than description_limit,

   • branding.icon is missing or isn’t shaped like a Feather icon name,

   • branding.color is missing or isn’t one of white, yellow, blue, green, orange, red, purple or gray-dark,

   • the repository is private.

Note

Two rules cannot be checked here and are called out in the log instead of being implied:

• the action’s name has to be unique across the Marketplace, which no offline check can establish; and

• branding.icon is checked for shape, not for membership in the accepted subset of Feather icons - that set is long and changes, so hard-coding it would go stale silently.

Dependencies

• GitHub: actions/checkout

• GitHub: actions/setup-python

• ruamel.yaml

Instantiation

The job needs no parameters when the metadata file is the conventional action.yml at the repository root. Making the release jobs depend on it keeps a release from being tagged with metadata the Marketplace would reject.

jobs:
  CheckMarketplace:
    uses: pyTooling/Actions/.github/workflows/CheckMarketplaceMetadata.yml@r8

  # Other pipeline jobs

  TriggerTaggedRelease:
    uses: pyTooling/Actions/.github/workflows/TagReleaseCommit.yml@r8
    needs:
      - Prepare
      - CheckMarketplace
    if: needs.Prepare.outputs.is_release_commit == 'true'
    permissions:
      contents: write
      actions:  write
    with:
      version:  ${{ needs.Prepare.outputs.version }}
      auto_tag: ${{ needs.Prepare.outputs.is_release_commit }}
    secrets: inherit

Parameter Summary

Goto input parameters

Parameter Name	Required	Type	Default
ubuntu_image	no	string	'ubuntu-26.04'
python_version	no	string	'3.14'
action_file	no	string	'action.yml'
description_limit	no	number	125

Goto secrets

This job template needs no secrets.

Goto output parameters

This job template has no output parameters.

Input Parameters

ubuntu_image

Type:

string

Required:

no

Default Value:

'ubuntu-26.04'

Possible Values:

See actions/runner-images - Available Images for available Ubuntu image versions.

Description:

Name of the Ubuntu image used to run this job.

python_version

Type:

string

Required:

no

Default Value:

'3.14'

Possible Values:

Any Python version supported by GitHub: actions/setup-python.

Description:

Python version used to read and check the metadata file.

action_file

Type:

string

Required:

no

Default Value:

'action.yml'

Possible Values:

'action.yml' or 'action.yaml'.

Description:

Action metadata file. GitHub Marketplace requires it at the repository root, so a path pointing elsewhere is reported as a violated rule rather than checked.

description_limit

Type:

number

Required:

no

Default Value:

125

Possible Values:

A positive number.

Description:

Maximum length of the action’s description, exclusive. The Marketplace form rejects a longer description with “Description must be less than 125 characters.”, so a description of exactly this length is already too long.

Secrets

This job template needs no secrets.

Outputs

This job template has no output parameters.

Optimizations

Every rule is evaluated before the job fails, so one run reports all violations instead of one per pipeline run.