Docker container with git-sync returns Host key verification failed when doing git fetch

Question

My docker-compose.yml looks like:

gitsync:
    image: openweb/git-sync:0.0.1
    restart: always
    command: >
      sh -c "ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa &&
             ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts &&
             chmod 600 ~/.ssh/id_rsa &&
             chmod 600 ~/.ssh/known_hosts"
    environment:
      GIT_SYNC_REPO: [email protected]:{company}/{repo_name}.git
      GIT_SYNC_DEST: /opt/airflow/dags/my_folder
      GIT_SYNC_BRANCH: master
      GIT_SYNC_SSH: 1
      GIT_SSH_KEY_FILE: ~/.ssh/id_rsa
      GIT_SSH_KNOWN_HOSTS_FILE: ~/.ssh/known_hosts
    volumes:
    - ./database_utils:/database_utils
    - ./maintenance:/maintenance
    - ./utils:/utils
    - ./dags:/opt/airflow/dags
    - ./logs:/opt/airflow/logs

The error that I get is:

2022/02/02 16:29:36 error syncing repo: error running command "git fetch origin master": exit status 128: Host key verification failed.
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

The repository exists because that docker-compose.yml worked when the content was setup to do it through https:

gitsync:
    image: openweb/git-sync:0.0.1
    restart: always
    environment:
      GIT_SYNC_REPO: https://{user}:{personal-access-token}@github.com/{company}/{repo_name}.git
      GIT_SYNC_DEST: /opt/airflow/dags/my_folder
      GIT_SYNC_BRANCH: master
    volumes:
    - ./database_utils:/database_utils
    - ./maintenance:/maintenance
    - ./utils:/utils
    - ./dags:/opt/airflow/dags
    - ./logs:/opt/airflow/logs

I tried to setup the grants to 600 as I read otherwise the key won't be used. Any idea how to fix it?

EDIT: test with dockerfile

I changed docker-compose.yml to:

  gitsync:
    image: my-gitsync-image
    restart: always
    container_name: my-gitsync
    build:
      context: .
      dockerfile: Dockerfile-gitsync
    environment:
      GIT_SYNC_REPO: [email protected]:{company}/{repo}.git
      GIT_SYNC_DEST: /opt/airflow/dags/my_folder
      GIT_SYNC_BRANCH: master
      GIT_SYNC_SSH: 1
      GIT_SSH_KEY_FILE: ~/.ssh/id_rsa
      GIT_SSH_KNOWN_HOSTS_FILE: ~/.ssh/known_hosts

And created a Dockerfile-gitsync as:

FROM openweb/git-sync:0.0.1

    RUN ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa
    RUN ssh-keyscan -t rsa github.com >> ~/.ssh/known_hosts
    RUN chmod 600 ~/.ssh/id_rsa
    RUN chmod 600 ~/.ssh/known_hosts

Now the error is:

2022/02/02 17:53:41 error syncing repo: error running command "git fetch origin master": exit status 128: Permission denied (publickey).
fatal: Could not read from remote repository.

Please make sure you have the correct access rights
and the repository exists.

So I guess that know known host is working but ssh key doesn't like it. I tried doing:

RUN ssh-keygen -q -t rsa -N '' -f ~/.ssh/id_rsa -C "[email protected]" 

But doesn't work neither.

Answer 1

$ ssh-keyscan -t rsa https://github.com/
getaddrinfo https://github.com/: Name or service not known

SSH doesn't know anything about https://github.com/. It must be just host, not an URL (not to say that SSH and HTTPS URL contradicts a bit, right?)

$ ssh-keyscan github.com
# github.com:22 SSH-2.0-babeld-e47cd09f
github.com ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAq2A7hRGmdnm9tUDbO9IDSwBK6TbQa+PXYPCPy6rbTrTtw7PHkccKrpp0yVhp5HdEIcKr6pLlVDBfOLX9QUsyCOV0wzfjIJNlGEYsdlLJizHhbn2mUjvSAHQqZETYP81eFzLQNnPHt4EVVUh7VfDESU84KezmD5QlWpXLmvU31/yMf+Se8xhHTvKSCZIFImWwoG6mbUoWf9nzpIoaSjB+weqqUUmpaaasXVal72J+UX2B+2RPW3RcT0eOzQgqlJL3RKrTJvdsjE3JEAvGq3lGHSZXy28G3skua2SmVi/w4yCE6gbODqnTWlg7+wC604ydGXA8VJiS5ap43JXiUFFAaQ==
# github.com:22 SSH-2.0-babeld-e47cd09f
github.com ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=
# github.com:22 SSH-2.0-babeld-e47cd09f
github.com ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl
# github.com:22 SSH-2.0-babeld-e47cd09f
# github.com:22 SSH-2.0-babeld-e47cd09f