There are several swarm cluster features that are enabled or configured when you initialize the cluster on the first manager node via the docker swarm init command. There may be times that you want to change which features are enabled, disabled, or configured after the cluster has been initialized. To accomplish this, you will need to use the swarm update command. For example, you may want to enable the auto-lock feature for your swarm cluster. Or, you might want to change the length of time that certificates are valid for. These are the types of changes you can execute using the swarm update command. Doing so might look like this:

# Enable autolock on your swarm cluster
docker swarm update --autolock=true
# Adjust certificate expiry to 30 days
docker swarm update --cert-expiry 720h

Here is the list of settings that can be affected by the swarm update command: