tagrep

A cli tool for parsing TAG_KEY=TAG_VALUE from GitHub pull requests, GitHub Issues, GitLab Merge Requests, GitLab Issues, etc.

This is not an official Google product.

Problem Statement

Users of version control platforms (e.g. GitHub, GitLab) often need to enable more robust functionality in their workflows. For example:

• Free form justification for a specific action being taken (e.g. Access on Demand request, audit trail of specific action)
• Acknowledgement of a condition (e.g. ignore code freeze)
• Turn on and off features (e.g. requiring all reviewers to approve before merge)
• etc

Existing functionality in GitHub and GitLab is not sufficient to natively support enabling all of these use cases. Instead, we need a tool that can parse metadata from GitHub and GitLab merge/pull requests and issues.

How it works

Users can add any metadata as semi-structured tags in their Merge/Pull Request or Issue body/description and the data will be fetched and parsed into a machine readable format.

Example merge/pull request:

fix: some bug

WANT_LGTM=all
ACK_OTHER_THING=yes

Example issue:

AOD request for access to production service ABC

JUSTIFICATION=I need access so I can delete the database

You can use tagrep in a GitHub or GitLab workflow to fetch and parse these tags:

tagrep parse -type=request -format=json
# Outputs:
{
  "WANT_LGTM":"all",
  "ACK_OTHER_THING":"yes"
}

tagrep parse -type=issue -format=raw
# Outputs:
JUSTIFICATION=I need access so I can delete the database

Usage

For more information about available commands and options, run a command with -help to use detailed usage instructions.

parse

The parse command fetches the target request or issue and parses all tags

# Parse an issue and output the format in ENV var syntax.
tagrep parse -type=issue -format=raw

# Parse a github pull request or gitlab merge request and output the format as a JSON object.
tagrep parse -type=request -format=json

CLI Flags

flag	required	possible values	description
-type	x	issue, request	Whether to fetch a github/gitlab issue or pull/merge request.
-format		json, raw	The format to output as. json will output as a single json object. raw will output as separate rows parsable into env variables.
-duplicate-key-strategy		take-last, array	How to handle multiple lines with the same tag key. array will concatenate the values indicated by -array-fields into a json array (even if the format is raw).
-array-fields		{{any}}	The fields that should be treated as an array. To be combined with -duplicate-key-strategy=array

GitHub Optional Flags

These options will be automatically parsed from the GitHub context if available.

flag	description
-github-token	The github token to use. Defaults to taking the GITHUB_TOKEN env variable.
-github-owner	The github organization/owner of the repository.
-github-repo	The github repository to access.
-github-app-id	The ID of the github application to auth as. Used instead of the -github-token
-github-app-installation-id	The installation of ID of the github application.
-github-app-private-key-pem	The private key pem file to use to auth to the github application.
-github-pull-request-number	The number of the pull request to parse.
-github-issue-number	The number of the issue to parse.

GitLab Optional Flags

These options will be automatically parsed from the GitLab context if available.

flag	description
-tagrep-gitlab-token	The gitlab token to use. Defaults to taking the TAGREP_GITLAB_TOKEN env variable.
-gitlab-base-url	The base url to send api requests to. Defaults to the GITLAB_BASE_URL env var.
-gitlab-project-id	The ID of the project to access
-gitlab-merge-request-iid	The GitLab project-level merge request internal ID.
-gitlab-issue-iid	The GitLab project-level issue internal ID.

Examples

GitHub - Exporting tags as environment variables

on:
  issues:
    types: ['opened', 'edited']

permissions:
  pull-requests: 'read' # Only required if type is 'request'
  issues: 'read'        # Only required if type is 'issue'

tagrep:
  runs-on: 'ubuntu-latest'
  steps:
  - name: 'Export Tags to ENV'
    shell: 'bash'
    env:
      GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
    run: |
      tagrep parse -type={{type}} -format=raw >> "$GITHUB_ENV"

  - name: 'Print out env vars'
    shell: 'bash'
    run: |
      echo "$SOME_TAG_THAT_MAY_BE_IN_ISSUE"

GitHub - Exporting tags as a single JSON output

permissions:
  pull-requests: 'read' # Only required if type is 'request'
  issues: 'read'        # Only required if type is 'issue'

tagrep:
  runs-on: 'ubuntu-latest'
  steps:
  - name: 'Export Tags as json to Output'
    id: 'json'
    shell: 'bash'
    env:
      GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
    run: |
      echo "tags=$(tagrep parse -type={{type}} -format=json)" >> "$GITHUB_OUTPUT"

  - name: 'Print output'
    shell: 'bash'
    run: |
      echo "${{ fromJSON(steps.json.outputs.tags)["SOME_TAG_THAT_MAY_BE_IN_ISSUE"] }}"

GitHub - Usage in a GitHub Pull Request or Merge Queue

on:
  pull_request:
  merge_group:

permissions:
  pull-requests: 'read'

tagrep:
  runs-on: 'ubuntu-latest'
  steps:
  - name: 'Export Tags to ENV'
    shell: 'bash'
    env:
      GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
    run: |
      tagrep parse -type=request -format=raw >> "$GITHUB_ENV"

GitHub - Usage in a GitHub Issue

on:
  issues:
    types: ['opened', 'edited']

permissions:
  issues: 'read'

tagrep:
  runs-on: 'ubuntu-latest'
  steps:
  - name: 'Export Tags to ENV'
    shell: 'bash'
    env:
      GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
    run: |
      tagrep parse -type=issue -format=raw >> "$GITHUB_ENV"

GitLab - Exporting tags as environment variables

TODO

GitLab - Exporting tags as a single JSON output

TODO

GitLab - Usage in a GitLab Merge Request or Merge Train

TODO

GitLab - Usage in a GitLab Issue

TODO

Auth

• The cli tool first resolves the GITHUB_TOKEN (github) or CI_JOB_TOKEN (gitlab) automatically from the environment.
• You can instead auth as a GitHub application by including the following flags: -github-app-id, -github-app-installation-id, -github-app-private-key-pem.