Ensure that the --terminated-pod-gc-threshold argument is set as appropriate (Controller Manager)

Activate garbage collector on pod termination, as appropriate. Garbage collection is important to ensure sufficient resource availability and avoiding degraded performance and availability. In the worst case, the system might crash or just be unusable for a long period of time. The current setting for garbage collection is 12,500 terminated pods which might be too high for your system to sustain. Based on your system resources and tests, choose an appropriate threshold value to activate garbage collection.

Risk Level: High
Cloud Entity: Pods
CloudGuard Rule ID: D9.K8S.IAM.11
Covered by Spectral: Yes
Category: Compute

GSL LOGIC

KubernetesPod where labels contain [value='kube-controller-manager'] and namespace = 'kube-system' should have spec.containers with [parsedArgs contain [key like 'terminated-pod-gc-threshold' ]]

REMEDIATION

Edit the Controller Manager pod specification file $controllermanagerconf
on the master node and set the --terminated-pod-gc-threshold to an appropriate threshold, for example:
--terminated-pod-gc-threshold=10

References

  1. https://kubernetes.io/docs/admin/kube-controller-manager/
  2. https://github.com/kubernetes/kubernetes/issues/28484

Pods

Pods are the smallest deployable units of computing that can be created and managed in Kubernetes.A Pod is a group of one or more containers (such as Docker containers), with shared storage/network, and a specification for how to run the containers.

Compliance Frameworks

  • CIS Kubernetes Benchmark v1.20
  • CIS Kubernetes Benchmark v1.23
  • CIS Kubernetes Benchmark v1.24
  • CIS Kubernetes Benchmark v1.4.0
  • CIS Kubernetes Benchmark v1.5.1
  • CIS Kubernetes Benchmark v1.6.1
  • Kubernetes NIST.SP.800-190
  • Kubernetes v.1.13 CloudGuard Best Practices
  • Kubernetes v.1.14 CloudGuard Best Practices