Unable to pull updates from Git repository in Plesk: Permission denied: Could not read from remote repository

Symptoms

• When trying to pull updates for a domain example.com from remote Git repository using SSH key authorization the following error is produced:

  PLESK_ERROR: Trying to pull the updates from git repository results in the error:
  Server at 'github.com' is seen for the first time. Adding its public key to the list of known hosts in '/var/www/vhosts/example.com/sub.example.com/.ssh/git_known_hosts'.
  # github.com:22 SSH-2.0-libssh_0.7.0
  # github.com:22 SSH-2.0-libssh_0.7.0
  # github.com:22 SSH-2.0-libssh_0.7.0
  Warning: Permanently added the RSA host key for IP address '203.0.113.2' to the list of known hosts. Permission denied (publickey). fatal: Could not read from remote repository. Please make sure you have the correct access rights and the repository exists.

• The main system user's name was recently changed.

Cause

This is a Plesk bug with ID PPPM-7291, which is planned to be fixed in one of the future product updates.

Resolution

As a workaround, perform the following steps:

1. Connect to the Plesk server via SSH.

2. Place the SSH keys for authentication in the home directory of an additional FTP user from the error (e.g. content of /var/www/vhosts/example.com/.ssh/ directory to /var/www/vhosts/example.com/sub.example.com/.ssh/):

   # mkdir -p /var/www/vhosts/example.com/sub.example.com/.ssh/
   # cp -ap /var/www/vhosts/example.com/.ssh/* /var/www/vhosts/example.com/sub.example.com/.ssh/

3. In case file is present, make sure that correct permissions are set:

   # chown jdoe:psacln /var/www/vhosts/example.com/sub.example.com/.ssh/id_rsa
   # chmod 600 /var/www/vhosts/example.com/sub.example.com/.ssh/*

   Where jdoe is the system user of the subscription.