pod-restarts-check

Pod Restarts Check

The Pod Restarts Check checks for excessive pod restarts in a given POD_NAMESPACE. When the spec is applied to your cluster, Kuberhealthy recognizes it as a KHCheck resource and provisions a checker pod to run the Pod Restarts Check.

The Pod Restarts Check deploys a pod that looks for pod resource events in a given POD_NAMESPACE and checks for Warning event types with reason BackOff. If this specific event type count exceeds the MAX_FAILURES_ALLOWED, an error is reporting back to Kuberhealthy.

In the example below, the check runs every 5m (spec.runInterval) with a check timeout set to 10 minutes (spec.timeout), and a MAX_FAILURES_ALLOWED count set to 10. If the check does not complete within the given timeout it will report a timeout error on the status page.

Pod Restarts Check Kube Spec:

apiVersion: comcast.github.io/v1
kind: KuberhealthyCheck
metadata:
  name: pod-restarts
  namespace: kuberhealthy
spec:
  runInterval: 5m
  timeout: 10m
  podSpec:
    containers:
      - env:
          - name: POD_NAMESPACE
            value: "kube-system"
          - name: MAX_FAILURES_ALLOWED
            value: "10"
        image: kuberhealthy/pod-restarts-check:v2.3.3
        imagePullPolicy: IfNotPresent
        name: main
        resources:
          requests:
            cpu: 10m
            memory: 50Mi

Options

By default, Pod Restarts Check will check pods in the same namespace it is installed into. This means the RBAC requirements for the service account the check runs with can be limited to a single namespace scope.

It is possible to configure Pod Restarts Check to check pods from all namespaces in a cluster, this requires cluster wide permissions for the service account and is not recommended for multi-tenant setups.

How-to

kubectl apply

To implement the Pod Restarts Check with Kuberhealthy, run:

kubectl apply -f https://raw.githubusercontent.com/Comcast/kuberhealthy/2.0.0/cmd/pod-restarts-check/pod-restarts-check.yaml

If you want to enable the cluster wide option described above then instead apply with cluster permissions pod-restarts-check-clusterscope.yaml.

Helm

helm repo add kuberhealthy https://comcast.github.io/kuberhealthy/helm-repos
helm install kuberhealthy kuberhealthy/kuberhealthy --set check.podRestarts.enabled=true

To enable cluster wide check with cluster permissions

helm install kuberhealthy kuberhealthy/kuberhealthy --set check.podRestarts.enabled=true --set check.podRestarts.allNamespaces=true

Make sure you are using the latest release of Kuberhealthy 2.0.0.