Final answer:
To update a previously draining and/or removed node from the swarm cluster, you can use the 'docker node update' command with the appropriate availability flag.
Step-by-step explanation:
To update a previously draining and/or removed node from the swarm cluster, you can use the command docker node update --availability active. This command sets the node's availability to active, meaning it will be included in the scheduling decisions of the swarm.
Alternatively, if you want to update the node's availability to drain, which means it will be drained of all tasks before being marked as inactive, you can use the command docker node update --availability drain. This can be useful if you want to gracefully remove a node from the cluster.
In case you want to mark a previously draining or removed node as ready and available for scheduling again, you can use the command docker node update --availability ready. This will set the node's availability to ready, allowing it to participate in scheduling decisions again.