Duplicate / Mirror a git repository to another without forking

git-mirror-repository.sh

#!/usr/bin/env bash

# Usage:
#     ./git-mirror-repository.sh "<source repository URL>" "<target repository URL>"
# Example:
#     ./mirror-gitlos-project.sh "git@gitlab.com:example/kickstart.git" "git@gitlab.com:example/acme.git"
#
# The user must have access to both existing repositories
#
# Warning! --mirror will do a force push - Use only once per project!

echo "Mirror project $1"

cd $(mktemp -d)
pwd
git clone --mirror $1
cd $(ls -d */ | head -n 1)
git push --mirror $2