actions-template-sync

abstract

Synchronise git repositories in an automated manner. Different git providers like GitHub (enterprise), GitLab,.. are supported as the source provider. This can help you e.g. for migration from another git provider to GitHub or if you want to mirror git repositories.

History

It is possible to create repositories within Github with GitHub templates. This is a nice approach to have some boilerplate within your repository. Over time, the template repository will get some code changes. The problem is that the already created repositories won't know about those changes. This GitHub action will help you to keep track of the template changes. The initial author of this repository faced that issue several times and decided to write a GitHub action to face that issue. Because of the nice community, several feature requests helped to go on with the development of the action. Now several other features are supported.

Features

flowchart LR
    github_source("fa:fa-github <b>GitHub</b> source repository <b>[private|public]</b>")
    gitlab_source("fa:fa-gitlab <b>GitLab</b> source repository <b>[private|public]</b>")
    any_source("fa:fa-git <b>Any</b> git provider <b>[private|public]</b>")
    github_target{{"fa:fa-github <b>GitHub</b> target repository <b>[private|public]</b>"}}
    github_source --> |"<b>ssh | PAT | github app</b>"| github_target
    gitlab_source --> |"<b>ssh</b>"| github_target
    any_source --> |"<b>ssh</b>"| github_target

• Sync other public or private repository (e.g. template repositories) with the current repository
• Ignore files and folders from syncing using a .templatesyncignore file
• many configuration options
• different lifecycle hooks are supported. This opens the possibility to inject custom code into the workflow with a yaml definition file.
• different git provider like GitLab, Gittea,.. as source are supported (with ssh). See .github/workflows/test_ssh_gitlab.yml for an example.
• It is not necessarily needed that source and target repository have the same base history. Because of that reason, it is possible to merge 2 totally different repositories with the help of the action.

Usage

Usage changes depending on whether the template repository is public or private, regardless of the visibility of the current repository.

Public template repository

Add this configuration to a GitHub action in the current repository:

# File: .github/workflows/template-sync.yml

on:
    # cronjob trigger
  schedule:
  - cron:  "0 0 1 * *"
  # manual trigger
  workflow_dispatch:
jobs:
  repo-sync:
    runs-on: ubuntu-latest

    steps:
      # To use this repository's private action, you must check out the repository
      - name: Checkout
        uses: actions/checkout@v3
      - name: actions-template-sync
        uses: AndreasAugustin/[email protected]
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          source_repo_path: <owner/repo>
          upstream_branch: <target_branch> # defaults to main
          pr_labels: <label1>,<label2>[,...] # optional, no default

You will receive a pull request within your repository if there are some changes available in the template.

Private template repository

If your current repository was created from a private template, there are several possibilities.

1. Using a GitHub app

You can create and use a GitHub App to handle access to the private template repository. To generate a token for your app you can use a separate action like tibdex/github-app-token. You have to set up the checkout step with the generated token as well.

jobs:
  repo-sync:
    runs-on: ubuntu-latest

    steps:
     - name: Generate token to read from source repo # see: https://github.com/tibdex/github-app-token
        id: generate_token
        uses: tibdex/github-app-token@v1
        with:
          app_id: ${{ secrets.APP_ID }}
          private_key: ${{ secrets.PRIVATE_KEY }}
      - name: Checkout
        uses: actions/checkout@v3
        with:
          token: ${{ steps.generate_token.outputs.token }}
      - name: actions-template-sync
        uses: AndreasAugustin/[email protected]
        with:
          github_token: ${{ steps.generate_token.outputs.token }}
          source_repo_path: <owner/repo>
          upstream_branch: <target_branch> # defaults to main
          pr_labels: <label1>,<label2>[,...] # optional, no default

2. Using SSH

You have various options to use ssh keys with GitHub. An example is deployment keys. For our use case, write permissions are not needed. Within the current repository, where the GitHub action is enabled, add a secret (e.q. SOURCE_REPO_SSH_PRIVATE_KEY) with the content of your private SSH key. Make sure that the read permissions of that secret fulfill your use case. Set the optional source_repo_ssh_private_key input parameter. It is also possible to use a different git provider, e.g. GitLab.

jobs:
  repo-sync:
    runs-on: ubuntu-latest

    steps:
      # To use this repository's private action, you must check out the repository
      - name: Checkout
        uses: actions/checkout@v3
      - name: actions-template-sync
        uses: AndreasAugustin/[email protected]
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          source_repo_path: ${{ secrets.SOURCE_REPO_PATH }} # <owner/repo>, should be within secrets
          upstream_branch: ${{ secrets.TARGET_BRANCH }} #<target_branch> # defaults to main
          pr_labels: <label1>,<label2>[,...] # optional, no default
          source_repo_ssh_private_key: ${{ secrets.SOURCE_REPO_SSH_PRIVATE_KEY }} # contains the private ssh key of the private repository

3. Using a PAT

⚠️ when the source repository is private using PATs, also the target repository must be private. Else it won't work.

Personal access token is an alternative to using passwords for authentication to GitHub. You can add a kind of password to your GitHub account. You need to set the scopes.

• repo -> all
• read:org

Furthermore, you need to set the access within the source repository to allow GitHub actions within the target repository. As mentioned before (you can see the note in the image) you need to set the target repository to private. settings -> actions -> general.

example workflow definition

name: actions-template-sync

on:
  # cronjob trigger At 00:00 on day-of-month 1. https://crontab.guru/every-month
  schedule:
  - cron:  "0 0 1 * *"
  # manual trigger
  workflow_dispatch:

jobs:
  test-implementation-job:

    runs-on: ubuntu-latest

    steps:
      # To use this repository's private action, you must check out the repository
      -
        name: Checkout
        uses: actions/checkout@v3
        with:
          token: ${{ secrets.CUSTOM_GITHUB_PAT }}
      -
        name: Test action step PAT
        uses: AndreasAugustin/[email protected]
        with:
          github_token: ${{ secrets.CUSTOM_GITHUB_PAT }}
          source_repo_path: ${{ secrets.SOURCE_REPO_PATH }} # <owner/repo>, should be within secrets

Configuration parameters

Docker

There are docker images available. Please checkout How to use docker for details.

Example

This repo uses this template and this action from the marketplace. See the definition here.

If you look for a more detailed guide you can have a look at Dev.to or GitHub

Trigger

You can use all triggers which are supported for GitHub actions

Ignore Files

Create a .templatesyncignore file. Just like writing a .gitignore file, follow the glob pattern in defining the files and folders that should be excluded from syncing with the template repository.

It can also be stored inside .github folder.

Note: It is not possible to sync also the .templatesyncignore itself. Any changes from the template repository will be restored automatically.

Remark reading the gitglossary (pathspec section) you see a slight difference to the .gitignore file when you like to disable files you need to use :!. E.g. when you like to disable the sync for all files with exceptions, you need to do smth like

:!newfile-1.txt
*

Lifecycle hooks

Different lifecycle hooks are supported. You need to enable the functionality with the option is_allow_hooks and set it to true ⚠️ use this functionality with caution. You can use one of the available docker images to test it out. With great power comes great responsibility.

• dockerhub andyaugustin/actions-template-sync
• github andreasaugustin/actions-template-sync

In addition, you need a configuration file with the name templatesync.yml within the root of the target repository.

The following hooks are supported (please check docs/ARCHITECTURE.md for a better understanding of the lifecycles).

• install is executed after the container has started and after reading and setting up the environment.
• prepull is executed before the code is pulled from the source repository
• prepush is executed before the push is executed, right after the commit
• prepr is executed before the PR is done

Remark The underlying OS is defined by an Alpine container. E.q. for the installation phase you need to use commands like apk add --update --no-cache python3

Schema and example for the temlatesync.yml

hooks:
  install:
    commands:
      - apk add --update --no-cache python3
      - python3 --version
  prepull:
    commands:
      - echo 'hi, we are within the prepull phase'
      - echo 'maybe you want to do adjustments on the local code'
  prepush:
    commands:
      - echo 'hi, we are within the prepush phase'
      - echo 'maybe you want to add further changes and commits'
  prepr:
    commands:
      - echo 'hi, we are within the prepr phase'
      - echo 'maybe you want to change the code a bit and do another push before creating the pr'

Troubleshooting

• refusing to allow a GitHub App to create or update workflow .github/workflows/******.yml without workflows permission

This happens because the template repository is trying to overwrite some files inside .github/workflows/. A GitHub action currently can't overwrite these files. To ignore those, simply create a file in the root directory named .templatesyncignore with the content .github/workflows/.

• pull request create failed: GraphQL: GitHub Actions is not permitted to create or approve pull requests (createPullRequest)

Open your project Settings > Actions > General and select the checkbox Allow GitHub Actions to create and approve pull requests under the Workflow permissions section.

Release Updates

• ⚠️ starting with version v1.0.0 the upstream_branch variable default is not main anymore. It is now set to the remote default branch.
• starting with version v0.5.2-draft the templateversionrc file is not needed anymore. You can delete that file from the target repositories.

Debug

You must create a secret named ACTIONS_STEP_DEBUG with the value true to see the debug messages set by this command in the log. For more information, see "Enabling debug logging."

Comparison with other tools

There are other great tools available within GitHub. Here you can find a comparison.

DEV

The development environment targets are located in the Makefile

make help

For some architectural notes please have a look at the docs

Contributors ✨

Thanks goes to these wonderful people (emoji key):

andy Augustin 📖 💻 👀 🛡️ 🤔 💬 💡 🖋 📝	Ugo Pattacini 📖	Jose Gabrielle Rivera 💻	P.D. Rittenhouse 🤔	Daniel Boll 🐛	albertschwarzkopf 🤔	Akul Pillai 🛡️
Stefan Riembauer 🤔	Fabrizio Cacicia 🛡️ 🐛	Justin Tunis 🤔 💻 🐛	Michael Matos 🐛	Gavin Williams 🤔	Marc Siebeneicher 🤔 💻 🐛 📖	Luís Henrique A. Schünemann 🤔 📖 💻
George 💬 📖 🤔	Pedro Rivero 🤔	Eleanor Bronson 🤔	Marvin Osswald 📖	David Calvert 📖 🐛 💻	Andy Airey 🐛	Surya Asriadie 🐛

This project follows the all-contributors specification. Contributions of any kind are welcome!