# Creating a Private Fork of a GitHub Repository

## Basic Steps

1. Create a new [private repository on Github](https://help.github.com/articles/creating-a-new-repository/)

2. Fork the repo (`BASE_REPO_URL`) to your new private repo (`PRIVATE_REPO_URL`) as follows:
    ```bash
    BASE_REPO_URL=<BASE>  # remote URL of repo you are forking
    PRIVATE_REPO_URL=<PRIVATE>  # remote URL of your new private fork repo

    # Create a bare clone of the base repo
    git clone --bare $BASE_REPO_URL

    # Mirror-push your bare clone to your new private repo
    cd ${BASE_REPO_URL##*/}
    git push --mirror $PRIVATE_REPO_URL

    # Remove the temporary local repository you created in step 2
    cd ..
    rm -rf ${BASE_REPO_URL##*/}
    ```

---

## Recommended Additional Steps

`cd` to your preferred workspace, then clone your private fork
```bash
git clone $PRIVATE_REPO_URL  # clone the private fork
cd ${${PRIVATE_REPO_URL##*/}%%.git}  # cd into the cloned directory

# add the original repo as remote to fetch (potential) future changes.
git remote add upstream $BASE_REPO_URL

# disable push on the remote (as you are not allowed to push to it anyway).
git remote set-url --push upstream DISABLE
```

* You can list all your remotes with `git remote -v`. You should see:
    ```
    origin	<PRIVATE_REPO_URL> (fetch)
    origin	<PRIVATE_REPO_URL> (push)
    upstream	<BASE_REPO_URL> (fetch)
    upstream	DISABLE (push)
    ```
* When you push, do so on `origin` with `git push origin`.
   
* When you want to pull changes from `upstream` you can just fetch the remote and rebase on top of your work.
  ```bash
    git fetch upstream
    git rebase upstream/main
  ```


Additional information on creating a private fork by duplicating a repo is documented [here](https://help.github.com/articles/duplicating-a-repository/).

see also: https://ellisbrown.github.io/programming/git-private-forks/#basic-steps