Introduction
Validating K8s Data
Netchecks can validate data stored in a ConfigMaps or Secret using the check type internal. If you have some other service storing results in a ConfigMap, you can use Netchecks to validate that the data is as expected using custom validation rules.
This may be useful for checking that a particular key exists in a ConfigMap or Secret, or that the data is valid JSON, Base64 encoded, truthy etc.
Example ConfigMaps Validation
Say you have a ConfigMap in the target namespace which contains a foo key that you want to assert has the value bar.
apiVersion: v1
kind: ConfigMap
metadata:
name: some-config-map
data:
foo: "bar"
Create a Network Assertion with a context to load the data from the ConfigMap and validate it.
apiVersion: netchecks.io/v1
kind: NetworkAssertion
metadata:
name: validate-some-configmap
annotations:
description: Assert that some configmap contains expected data
spec:
schedule: "*/15 * * * *"
context:
- name: somecontext
configMap:
name: some-config-map
rules:
- name: validate-bar
type: internal
expected: pass
validate:
message: Expected foo to be bar
pattern: "somecontext.foo == 'bar'"
Not familiar with ConfigMaps?
A ConfigMap in Kubernetes is commonly used to store configuration data for applications. Each ConfigMap is namespaced and stores key-value pairs.
Handling JSON and YAML data
Often a config map contains JSON or YAML data. The parse_json and parse_yaml functions can be used to extract data from these formats.
apiVersion: v1
kind: ConfigMap
metadata:
name: a-config-map
data:
yaml_data: |
toplevel:
nestedkey: "yaml-data"
apiVersion: netchecks.io/v1
kind: NetworkAssertion
metadata:
name: example-with-yaml-format
spec:
context:
- name: somecontext
configMap:
name: a-config-map
rules:
- name: yaml-parsing-test
type: internal
validate:
message: Inner yaml value
pattern: parse_yaml(somecontext.yaml_data).toplevel.nestedkey == "yaml-data"