Kubernetes

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

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: kube-system-checks
spec:
  interval: 30
  kubernetes:
      # failing checks will be inserted into kube-system, irrespective of which
      # namespace this canary is created in
    - namespace: kube-system
      name: kube-system
      kind: Pod
      ready: true
      resource:
        labelSelector: k8s-app=kube-dns
      namespaceSelector:
        name: kube-system

Field	Description	Scheme	Required
kind	Specifies the kind of Kubernetes object for interaction	string	Yes
resource	Queries resources related to specified Kubernetes object	ResourceSelector
namespaceSelector	Specifies namespace for Kubernetes object	ResourceSelector
ignore	Ignore the specified resources from the fetched resources. Can be a glob pattern.	[]string
ready	Check if resources are healthy using is-healthy if not fails the check	bool
name	Name of the check, must be unique within the canary	string	Yes
description	Description for the check	string
icon	Icon for overwriting default icon on the dashboard	string
labels	Labels for check	map[string]string
test	Evaluate whether a check is healthy	Expression
display	Expression to change the formatting of the display	Expression
transform	Transform data from a check into multiple individual checks	Expression
metrics	Metrics to export from	[]Metrics

Ready

Using ready: true is functionally equivalent to:

apiVersion: canaries.flanksource.com/v1
kind: Canary
metadata:
  name: kube-system-checks
spec:
  interval: 30
  kubernetes:
    - namespace: kube-system
      name: kube-system
      kind: Pod
      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')
      test:
        expr: dyn(results).all(x, k8s.isHealthy(x))

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

ResourceSelector

Field	Description	Scheme	Required
name	Name of Kubernetes resource	string
labelSelector	Select Kubernetes resource based on label. e.g. app, canary.	string
fieldSelector	Select Kubernetes resource based on the value of specified resource field	string

Examples

Certificate readiness

cert-manager-check.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')