Docker
TMA-DOCKER-7.1
Ensure that the minimum number of manager nodes have been created in a swarm
Description
You should ensure that the minimum number of required manager nodes is created in a swarm. Manager nodes within a swarm have control over the swarm and can change its configuration, including modifying security parameters. Having excessive manager nodes could render the swarm more susceptible to compromise. Reported as a manual review item: the audit needs a site-specific judgement.
How it is checked
Audit method: Manual review
Run docker info and verify the number of managers. docker info --format '{{ .Swarm.Managers }}' Alternatively run the below command. docker node ls | grep 'Leader' Expected state: If an excessive number of managers is configured, the excess nodes can be demoted to workers using the following command: docker node demote <ID> Where <ID> is the node ID value of the manager to be demoted.
How it is fixed
Fix method: Guidance or infrastructure patch
If an excessive number of managers is configured, the excess nodes can be demoted to workers using the following command: docker node demote <ID> Where <ID> is the node ID value of the manager to be demoted.
Properties
- Operating systems
- Any
- Tags
- dockermanual
- Reference
- CIS Docker Benchmark v1.9.0 - 7.1 Ensure that the minimum number of manager nodes have been created in a swarm