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kube-bench is a Go application that checks whether Kubernetes is deployed securely by running the checks documented in the [CIS Kubernetes Benchmark](https://www.cisecurity.org/benchmark/kubernetes/).
kube-bench supports the tests for multiple versions of Kubernetes (1.6, 1.7, 1.8, and 1.11) as defined in the CIS Benchmarks 1.0.0, 1.1.0, 1.2.0, and 1.30 respectively. It will determine the test set to run based on the Kubernetes version running on the machine.
> Note: the tests require either the kubelet or kubectl binary in the path in order to know the Kubernetes version. You can pass `-v $(which kubectl):/usr/bin/kubectl` to the above invocations to resolve this.
If Go is installed on the target machines, you can simply clone this repository and run as follows (assuming your [$GOPATH is set](https://github.com/golang/go/wiki/GOPATH)):
Kubernetes config and binary file locations and names can vary from installation to installation, so these are configurable in the `cfg/config.yaml` file.
For each type of node (*master*, *node* or *federated*) there is a list of components, and for each component there is a set of binaries (*bins*) and config files (*confs*) that kube-bench will look for (in the order they are listed). If your installation uses a different binary name or config file location for a Kubernetes component, you can add it to `cfg/config.yaml`.
* **bins** - If there is a *bins* list for a component, at least one of these binaries must be running. The tests will consider the parameters for the first binary in the list found to be running.
* **podspecs** - From version 1.2.0 of the benchmark (tests for Kubernetes 1.8), the remediation instructions were updated to assume that the configuration for several kubernetes components is defined in a pod YAML file, and podspec settings define where to look for that configuration.
* **confs** - If one of the listed config files is found, this will be considered for the test. Tests can continue even if no config file is found. If no file is found at any of the listed locations, and a *defaultconf* location is given for the component, the test will give remediation advice using the *defaultconf* location.
* **unitfiles** - From version 1.2.0 of the benchmark (tests for Kubernetes 1.8), the remediation instructions were updated to assume that kubelet configuration is defined in a service file, and this setting defines where to look for that configuration.
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.
Going forward we plan to release updates to kube-bench to add support for new releases of the Benchmark, which in turn we can anticipate being made for each new Kubernetes release.