Kubernetes

The Kubernetes check performs requests on Kubernetes resources such as Pods to get the desired information.

junit.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: kube-system-checks
spec:
  interval: 30
  kubernetes:
    - namespace: kube-system
      name: kube-system
      kind: Pod
      # ready: true
      # resource:
      #   labelSelector: k8s-app=kube-dns
      namespaceSelector:
        name: default
      display:
        expr: |
          dyn(results).
          map(i, i.Object).
          filter(i, !k8s.isHealthy(i)).
          map(i, "%s/%s -> %s".format([i.metadata.namespace, i.metadata.name, k8s.getHealth(i).message])).join('\n')
      test:
        expr: dyn(results).all(x, k8s.isHealthy(x))

Field	Description	Scheme
kind*	Kubernetes object kind	string
name*	Name of the check, must be unique within the canary	string
healthy	Fail the check if any resources are unhealthy	boolean
ignore	Ignore the specified resources from the fetched resources. Can be a glob pattern.	[]glob
namespace	Failing checks will be placed in this namespace, useful if you have shared namespaces
namespaceSelector	Namespace of the Kubernetes object	ResourceSelector
ready	Fail the check if any resources are not ready	boolean
resource	Queries resources related to specified Kubernetes object	ResourceSelector
description	Description for the check	string
display	Expression to change the formatting of the display	Expression
icon	Icon for overwriting default icon on the dashboard	Icon
labels	Labels for check	map[string]string
metrics	Metrics to export from	[]Metrics
test	Evaluate whether a check is healthy	Expression
transform	Transform data from a check into multiple individual checks	Expression
kubeconfig	Path to a kubeconfig on disk, or a reference to an existing secret	EnvVar

Healthy

Using healthy: true is functionally equivalent to the test expression above:

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: kube-system-checks
spec:
  interval: 30
  kubernetes:
    - namespace: kube-system
      name: kube-system
      kind: Pod
      healthy: true
      resource:
        labelSelector: k8s-app=kube-dns
      namespaceSelector:
        name: kube-system
      display:
        expr: |
          dyn(results).
          map(i, i.Object).
          filter(i, !k8s.isHealthy(i)).
          map(i, "%s/%s -> %s".format([i.metadata.namespace, i.metadata.name, k8s.getHealth(i).message])).join('\n')

See the CEL Kubernetes docs for more details on the k8s.isHealthy and other functions available

Ready

Similar to the healthy flag, there's also a ready flag which is functionally equivalent to having the following test expression

dyn(results).all(x, k8s.isReady(x))

---

Checking for certificate readiness

junit.yaml
apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: cert-manager
spec:
  schedule: "@every 15m"
  kubernetes:
    - name: cert-manager-check
      kind: Certificate
      test:
        expr: |
          dyn(results).
          map(i, i.Object).
          filter(i, i.status.conditions[0].status != "True").size() == 0
      display:
        expr: |
          dyn(results).
          map(i, i.Object).
          filter(i, i.status.conditions[0].status != "True").
          map(i, "%s/%s -> %s".format([i.metadata.namespace, i.metadata.name, i.status.conditions[0].message])).join('\n')