The Kubernetes Bench for Security is a Go application that checks whether Kubernetes is deployed securely by running the checks documented in the CIS Kubernetes 1.6 Benchmark v1.0.0.
Tests are configured with YAML files, making this tool easy to update as test specifications evolve.
You can either install kube-bench through a dedicated container, or compile it from source:
docker run --rm -v `pwd`:/host aquasec/kube-bench:latest. This will copy the kube-bench binary and configuration to you host. You can then run
Install from sources:
If Go is installed on the target machines, you can simply clone this repository and run as follows:
go get github.com/aquasecurity/kube-bench
cp $GOROOT/bin/kube-bench .
Available Commands: federated Run benchmark checks for a Kubernetes federated deployment. help Help about any command master Run benchmark checks for a Kubernetes master node. node Run benchmark checks for a Kubernetes node. Flags: -c, --check string A comma-delimited list of checks to run as specified in CIS document. Example --check="1.1.1,1.1.2" --config string config file (default is ./cfg/config.yaml) -g, --group string Run all the checks under this comma-delimited list of groups. Example --group="1.1" --installation string Specify how kubernetes cluster was installed. Possible values are default,hyperkube,kops,kubeadm (default "default") --json Prints the results as JSON -v, --verbose verbose output (default false)
Kubernetes config and binary file locations and names can vary from installation to installation, so these are configurable in the
They also tend to vary according to which tool was used to install Kubernetes. You can use the
--installation flag to pick up a different default set of file names and locations. Again these defaults are configurable through
cfg/config.yaml (and pull requests to correct or add default file locations are especially welcome).
Test config YAML representation
The tests are represented as YAML documents (installed by default into ./cfg).
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: bin_op: or test_items: - flag: "--allow-privileged" set: true - flag: "--some-other-flag" set: false remediation: "Edit the /etc/kubernetes/config file on the master node and set the KUBE_ALLOW_PRIV parameter to '--allow-privileged=false'" scored: true
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
federated apiserver to reflect the various Kubernetes node types.
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.
The tests are up-to-date with the CIS Benchmark 1.1.0, which refers to Kubernetes 1.7. Going forward we should release updates to kube-bench to reflect new releases of the Benchmark, which in turn we can anticipate being made for each new Kubernetes release.