privatefork.sh

#!/bin/bash
set -e

# Usage:
# ./privatefork.sh <public-repository-url> [-p <personal-access-token>] [-n]

### Environment Variables
# - Public repository URL
# -p: `PAT` (Personal Access Token), optionally provided and will override the default PAT.
# -n: Skip cleanup of the local repository clone.

### NOTE: You could set up the script as an executable and making it globally available:
# sudo chmod +x privatefork.sh
# sudo cp privatefork.sh /usr/local/bin
# echo 'export PATH="$PATH:/usr/local/bin"' >> ~/.bashrc

### Script Functions:
# 1. Clone the specified GitHub repository.
# 2. Create a private fork of the repository on the user's GitHub account.
# 3. Push all branches from the cloned repository to the new private fork.

### Packages Required
# - Shell Script
# - Git
# - GitHub API
# - python


PAT=ghp_XXXXX  # Default PAT, replace or use -p flag to overwrite
skip_cleanup=false  # Variable to control cleanup

# Function to display usage
usage() {
    echo "Usage: $0 <repository-url> [-p <personal-access-token>] [-n]"
    echo "  -p: Specify a personal access token"
    echo "  -n: Skip cleanup of the local repository clone"
    exit 1
}

#### Packages Required
# - Shell Script
# - Git
# - GitHub API
# - python, or jq (Command-line JSON processor)


# Check if at least one argument is provided
if [ "$#" -eq 0 ]; then
    usage
fi

# Mandatory argument
REPO_URL="$1"
shift

# Parse optional arguments
while getopts ":p:n" opt; do
    case $opt in
        p)
            PAT=$OPTARG
            ;;
        n)
            skip_cleanup=true
            ;;
        \?)
            echo "Invalid option: -$OPTARG" >&2
            usage
            ;;
        :)
            echo "Option -$OPTARG requires an argument." >&2
            usage
            ;;
    esac
done

echo "Personal Access Token: $PAT"
echo "skip cleanup $skip_cleanup"


REPO_NAME=$(basename -s .git "$REPO_URL")
# Use Python to parse JSON and extract the user's login name
USER_NAME=$(curl -s -H "Authorization: token $PAT" https://api.github.com/user | python -c "import sys, json; print(json.load(sys.stdin)['login'])")
# or, use jq to parse JSON and extract the user's login name
# USER_NAME=$(curl -s -H "Authorization: token $PAT" https://api.github.com/user | jq -r .login)
NEW_REPO_URL="https://$USER_NAME:$PAT@github.com/$USER_NAME/$REPO_NAME.git"

# Clone the repository
git clone --mirror "$REPO_URL"
cd "$REPO_NAME.git" || exit

# Set the original repository as the upstream for fetching updates
git remote add upstream "$REPO_URL"

# Disable push to upstream
git remote set-url --push upstream DISABLE

# Create a new private repository on GitHub
curl -H "Authorization: token $PAT" https://api.github.com/user/repos -d "{\"name\":\"$REPO_NAME\",\"private\":true}"

# # Push all branches to the new private repository
# git push --mirror "$NEW_REPO_URL"

# List all local branches and filter out pull request refs
branches=$(git for-each-ref --format='%(refname)' refs/heads/)

# Push each branch individually to avoid pushing pull request refs
for branch in $branches; do
    git push "$NEW_REPO_URL" "${branch}:refs/heads/$(basename $branch)"
done

# Cleanup
if [ "$skip_cleanup" = false ]; then
  echo "Cleaning up..."
  cd ..
  rm -rf "$REPO_NAME.git"
fi

echo "Private fork created and all branches pushed to $NEW_REPO_URL"

Here is the script for you to fork a repo and make it private. This script maintains the old public repo as "upstream", and your private repo as "origin"