CircleCI config.yml for mirroring a sub-directory from Github repo

config.yml

version: 2.1

jobs:
  mirror:
    docker:
      - image: circleci/node:lts

    steps:
      - checkout

      - run:
          name: Prepare for mirroring
          command: |
            git config --global user.email "your.github@email.com"
            git config --global user.name "Your Name"
            # Need to create .ssh dir in case it doesn't exists
            mkdir -p ~/.ssh
            # This too
            touch ~/.ssh/known_hosts
            # To avoid prompt when doing ssh connection
            ssh-keyscan 'github.com' >> ~/.ssh/known_hosts
            
      - run:
          name: Mirroring repo
          command: |
            git filter-branch --prune-empty --subdirectory-filter ${SUB_DIR_NAME} ${BRANCH}
            git remote add mirror git@github.com:oshimayoan/something-mirror.git
            git push mirror master
            
workflows:
  main:
    jobs:
      - mirror:
          filters:
            branches:
              only: master