Master OpenShift Troubleshooting Commands for Interviews

techhadoop OCP

For OpenShift interviews (Administrator, Engineer, Architect), there are about 40-50 commands that come up repeatedly. Interviewers often ask:

“What commands would you use to troubleshoot this?”

Below is a practical cheat sheet.

Cluster Health

Check cluster operators
oc get co

Healthy:

AVAILABLE=True
DEGRADED=False
Check nodes
oc get nodes

Detailed:

oc describe node <node>
Node resource usage
oc adm top nodes

Pods

List pods
oc get pods -A

Wide output:

oc get pods -A -o wide
Describe pod
oc describe pod <pod>
Pod logs
oc logs <pod>

Previous container:

oc logs <pod> --previous
Execute into pod
oc exec -it <pod> -- bash

Deployments

List deployments
oc get deployment -A
Deployment status
oc rollout status deployment/<name>
Deployment history
oc rollout history deployment/<name>
Rollback deployment
oc rollout undo deployment/<name>

Services

List services
oc get svc
Describe service
oc describe svc <service>
Endpoints
oc get endpoints

Critical troubleshooting command.

Routes

List routes
oc get routes
Route details
oc describe route <route>
Test route
curl https://<route>

Projects / Namespaces

List projects
oc get projects
Switch project
oc project my-project
Create project
oc new-project my-project

Storage

Persistent Volumes
oc get pv
PVCs
oc get pvc
Describe PVC
oc describe pvc <pvc>
Storage classes
oc get sc

Networking

Network policies
oc get networkpolicy -A
DNS pods
oc get pods -n openshift-dns
OVN pods
oc get pods -n openshift-ovn-kubernetes
Debug node
oc debug node/<node>

Inside:

chroot /host

Very common interview command.

Operators

Installed operators
oc get csv -A
Operator subscriptions
oc get subscriptions -A
Operator status
oc get installplans -A

Authentication

Current user
oc whoami
Login
oc login
Check permissions
oc auth can-i create pods
Role bindings
oc get rolebindings -A

Certificates

CSRs
oc get csr
Approve CSR
oc adm certificate approve <csr>

Monitoring

Prometheus
oc get pods -n openshift-monitoring
Alertmanager
oc get pods -n openshift-monitoring

Look for:

prometheus-k8s
alertmanager-main

etcd

etcd pods
oc get pods -n openshift-etcd
Endpoint status
oc exec -n openshift-etcd etcd-master-0 \
-- etcdctl endpoint status -w table

Machine Config

MCP status
oc get mcp
Machine configs
oc get mc
Describe MCP
oc describe mcp worker

Troubleshooting Commands

Events
oc get events -A --sort-by=.metadata.creationTimestamp

Very important.

Resource usage
oc adm top pods -A

YAML output

oc get pod <pod> -o yaml

Explain resource

oc explain deployment.spec

Must Gather

One of the most common interview questions.

oc adm must-gather

Network logs:

oc adm must-gather -- /usr/bin/gather_network_logs

Backup & Restore

etcd backup

oc debug node/master-0
chroot /host
/usr/local/bin/cluster-backup.sh /backup

etcd restore

/usr/local/bin/cluster-restore.sh /backup

OADP / Velero

Backups
oc get backup -n openshift-adp
Restores
oc get restore -n openshift-adp
Schedules
oc get schedule -n openshift-adp

Top 15 Commands Interviewers Expect You To Know

oc get co
oc get nodes
oc get pods -A
oc describe pod
oc logs
oc exec -it
oc get events -A
oc adm top nodes
oc adm top pods
oc get routes
oc get pvc
oc get networkpolicy -A
oc get mcp
oc debug node/<node>
oc adm must-gather

If you’re interviewing for Senior OCP Engineer / Architect, I’d also memorize commands around:

  • OVN networking
  • etcd troubleshooting
  • OADP/Velero
  • MachineConfigPools
  • Operators
  • Certificate management
  • Monitoring/Prometheus

These are the areas most frequently explored in OpenShift 4.x interviews.

Leave a Reply