kube-bench/check

Checks

Checks are recommendations from the Center for Internet Security for Kubernetes 1.6+ installations.

YAML Representation

In this application these recommendations are represented as YAML documents. An example is as listed below:

---
controls:
id: 1
text: "Master Checks"
type: "master"
groups:
- id: 1.1
  text: "Kube-apiserver"
  checks:
    - id: 1.1.1
      text: "Ensure that the --allow-privileged argument is set (Scored)"
      audit: "ps -ef | grep kube-apiserver | grep -v grep"
      tests:
      - flag: "--allow-privileged"
        set: true
      remediation: "Edit the /etc/kubernetes/config file on the master node and set the KUBE_ALLOW_PRIV parameter to '--allow-privileged=false'"
      scored: true

Recommendations (called checks in this document) can run on Kubernetes Master, Node or Federated API Servers. Checks are organized into groups which share similar controls (things to check for) and are grouped together in the section of the CIS Kubernetes document. These groups are further organized under controls which can be of the type master, node or federated apiserver to reflect the various Kubernetes node types.

Tests

Tests are the items we actually look for to determine if a check is successful or not. Checks can have multiple tests, which must all be successful for the check to pass.

The syntax for tests:

tests:
- flag:
  set:
  compare:
    op:
    value:
...

Tests have various operations which are used to compare the output of audit commands for success. These operations are:

• eq: tests if the flag value is equal to the compared value.
• noteq: tests if the flag value is unequal to the compared value.
• gt: tests if the flag value is greater than the compared value.
• gte: tests if the flag value is greater than or equal to the compared value.
• lt: tests if the flag value is less than the compared value.
• lte: tests if the flag value is less than or equal to the compared value.
• has: tests if the flag value contains the compared value.
• nothave: tests if the flag value does not contain the compared value.