InformationEnsure that the minimum number of required manager nodes is created in a swarm.
Manager nodes within a swarm have control over the swarm and change its configuration modifying security parameters. Having excessive manager nodes could render the swarm more susceptible to compromise.
If fault tolerance is not required in the manager nodes, a single node should be elected as amanger. If fault tolerance is required then the smallest practical odd number to achieve the appropriate level of tolerance should be configured.
NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.
SolutionIf an excessive number of managers is configured, the excess can be demoted as worker using the following command:
docker node demote <ID>
Where <ID> is the node ID value of the manager to be demoted.
A single manager is all that is required to start a given cluster.