Apache NiFi Registry System Administrator's Guide
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Git user authentication

By default, this persistence repository only create commits to local repository. No user authentication is needed to do so. However, if 'Commit To Push' is enabled, user authentication to the remote Git repository is required.

If the remote repository is accessed by HTTP, then username and password for authentication can be configured in the providers XML configuration file.

When SSH is used, SSH keys are used to identify a Git user. In order to pick the right key to a remote server, the SSH configuration file ${USER_HOME}/.ssh/config is used. The SSH configuration file can contain multiple Host entries to specify a key file to login to a remote Git server. The Host must match with the target remote Git server hostname.

example SSH config file

Host git.example.com
  HostName git.example.com
  IdentityFile ~/.ssh/id_rsa

Host github.com
  HostName github.com
  IdentityFile ~/.ssh/key-for-github

Host bitbucket.org
  HostName bitbucket.org
  IdentityFile ~/.ssh/key-for-bitbucket