Pod status

Learn Pod status and phases.

Pod status

A pod's life cycle has phases:

Pending: accepted, not placed on a node yet or the image is being pulled.
Running: at least one container is running.
Succeeded: all containers finished successfully.
Failed: at least one container finished with an error.

The READY 1/1 column shows whether containers passed their readiness checks, and RESTARTS how many times they restarted.

NAME   READY   STATUS             RESTARTS      AGE
web    1/1     Running            0             5m
api    0/1     CrashLoopBackOff   4 (30s ago)   3m

Health checks

Kubernetes watches container health with probes:

livenessProbe: if it fails, the container is restarted (a hung application).
readinessProbe: while failing, the pod gets no traffic (not ready yet).
startupProbe: delays the other probes for slow-starting applications.

      readinessProbe:
        httpGet:
          path: /saglik
          port: 8080
        periodSeconds: 5
      livenessProbe:
        httpGet:
          path: /saglik
          port: 8080
        initialDelaySeconds: 10

Exercise A container with probes

Write a pod YAML: name api; container named api, image api:1.0; readinessProbe checks the /saglik path on port 8080 with httpGet; livenessProbe uses the same path and port.

Show example solution

apiVersion: v1
kind: Pod
metadata:
  name: api
spec:
  containers:
    - name: api
      image: api:1.0
      readinessProbe:
        httpGet:
          path: /saglik
          port: 8080
      livenessProbe:
        httpGet:
          path: /saglik
          port: 8080

Test yourself

If STATUS is Running but READY is 0/1, what does it mean?
- The pod was deleted
- The image can't be pulled
- Everything is fine
- The container runs but fails its readiness check; it gets no traffic
Show answer

The container runs but fails its readiness check; it gets no traffic — A Service sends traffic only to ready pods.

Write the probe that restarts the container when it fails.

      ____:
        httpGet:
          path: /saglik
          port: 8080

Show answer

      livenessProbe:
        httpGet:
          path: /saglik
          port: 8080

Match.

Pending

Waiting to be placed
Succeeded

Finished successfully
livenessProbe

Restart when hung
readinessProbe

No traffic if not ready

Next lesson: Multi-container Pod

We Are Enhancing Your Experience

Cookie Preferences

Strictly Necessary Cookies

Analytical Cookies