Liveness probe must be present (GITA-PRO-004)

Kubernetes has a built in mechanism to detect whether a container is behaving accordingly, called Liveness Probe. This mechanism is implemented in the Kubelet component to detect when programs start to misbehave but have not yet crashed, as occurs in deadlocks and other issues which make the program unresponsive.

When the Kubelet detects a container in such a state, it restarts the container in an attempt to temporarily bring back its functionality by starting a fresh execution. If this is not set, Kubernetes will have no way to detect and remedy unresponsive containers.

How to perform a Liveness Probe depends greatly on the program in question, but an example is given below:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
    - name: redis
      image: redis:latest
      livenessProbe:
        exec:
          command:
            - redis-cli
            - ping
        initialDelaySeconds: 30
        timeoutSeconds: 5
        failureThreshold: 10

For more information, visit the Kubernetes documentation.