OpenShift Image Streams Explained¶
Introduction¶
OpenShift ImageStreams track image tags used by builds and deployments. They are useful for promotion and triggers, but a missing or stale ImageStreamTag can block rollout or image pull workflows.
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 import-image web:latest --from=quay.io/example/web:latest --confirm -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 imagestream web -n app
oc get events -n app --sort-by=.lastTimestamp
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¶
Summary¶
OpenShift Image Streams Explained is best understood through the OpenShift objects involved and the oc commands that verify their current state.