OpenShift Deployments Explained¶

Introduction¶

OpenShift deployments manage application rollouts by updating pod templates and creating new ReplicaSets. Verify the Deployment, rollout history, pods, events, and route or service endpoints together.

Before You Start¶

Make sure you are in the correct project and know whether the application is driven by a Deployment, DeploymentConfig, BuildConfig, ImageStream, or external registry image.

Practical Examples¶

oc get deployment web -n app

oc rollout status deployment/web -n app

oc get replicasets -n app -l app=web

oc get pods -n app -l app=web

Example output:

NAME   READY   UP-TO-DATE   AVAILABLE   AGE
web    3/3     3            3           18m

deployment "web" successfully rolled out

Verification¶

oc describe deployment web -n app

oc rollout history deployment/web -n app

oc get endpoints web -n app

Troubleshooting¶

For deployment issues, check rollout status, ReplicaSets, pod events, readiness probes, and the image or configuration change that created the latest revision.

Common Mistakes¶

• Looking only at the final error and ignoring events.
• Checking the wrong project with oc.
• Changing several objects at once before confirming the current state.

Quick Checklist¶

• Confirm the active project.
• Inspect the exact object named in the error.
• Read recent events.
• Apply one focused fix.
• Verify status after the change.

Related Guides¶

• Openshift New App Explained
• Openshift Imagestream Explained
• Openshift Application Deployment Checklist

Summary¶

OpenShift Deployments Explained should be verified with commands that match the OpenShift object being changed or investigated.