OpenShift Registry Explained¶
Introduction¶
ImageStreams track image references inside OpenShift and can trigger deployments when tags change. For registry problems, verify the ImageStreamTag, pull secret, and whether the internal registry is reachable.
Core Concepts¶
OpenShift builds on Kubernetes with projects, Routes, ImageStreams, Builds, Operators, SCCs, and integrated platform administration.
Practical Examples¶
oc get imagestream web -n app
oc get istag web:latest -n app
oc describe istag web:latest -n app
oc get secret -n app
Example output:
NAME IMAGE REPOSITORY TAGS UPDATED
web image-registry.openshift-image-registry.svc:5000/app/web latest 4 minutes ago
Verification¶
oc get istag web:latest -n app
oc describe pod -l app=web -n app
oc get secret pull-secret -n app
Common Mistakes¶
- Using an ImageStreamTag that has no imported image.
- Missing imagePullSecrets for external private registries.
- Confusing the internal registry service name with the external route.
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¶
Summary¶
OpenShift Registry Explained is best understood through the OpenShift objects involved and the oc commands that verify their current state.