Answer :
Final answer:
The docker swarm unlock-key --rotate command is used to rotate the unlock key for a Docker Swarm, which enhances the security by invalidating the old key and generating a new one.
Explanation:
The docker swarm unlock-key --rotate command is used to rotate the swarm unlock key. Docker Swarm uses mutual TLS for node authentication and encryption to secure communications between nodes in the swarm. A feature of this security measure is an unlock key that prevents unauthorized access to the swarm if it gets locked for security reasons. If a manager node gets locked, for instance after a restart, it needs this key to rejoin the swarm. Rotating the unlock key means generating a new key which invalidates the old one, enhancing the security of the swarm.
