OpenShift Tutorial – Basic Learning Workflow

How to login?

oc login https://api.XXXXXXXXXXXXXX.centralindia.aroapp.io:6443 --username=kubeadmin --password=EgzIY-DJPw2-3NXke-HNYmJ

oc login --token=sha256~LLnTlPcjcNjWsQRqnSyTn99LSvxwQdm47gaiEdZJa20 --server=https://api.XXXXXXXXXXXXXX.centralindia.aroapp.io:6443

curl -H "Authorization: Bearer sha256~LLnTlPcjcNjWsQRqnSyTn99LSvxwQdm47gaiEdZJa20" "https://api.XXXXXXXXXXXXXX.centralindia.aroapp.io:6443/apis/user.openshift.io/v1/users/~

Login to the Web Console and CLI on CRC

crc console --credentials
eval $(crc oc-env)
oc login -u kubeadmin -p <password> --insecure-skip-tls-verify

Copy the admin URL and kubeadmin credentials → open in browser.

Step 2: Understand Projects (Namespaces)

List All Projects:

oc get projects

Create Your Own:

oc new-project demo-app

Step 3: Deploy Your First Application

oc get images
oc new-app --name=my-java-app registry.access.redhat.com/ubi8/openjdk-8-runtime@sha256:00cf28cf9a6c427962f922855a6cc32692c760764ce2ce7411cf605dd510367f
oc expose svc/my-java-app


oc get imagestreams -n openshift
oc new-app --name=my-httpd --image-stream=openshift/httpd
oc expose svc/my-httpd
oc get route my-httpd

Test in browser using the exposed route.

Step 4: Work with the Developer Console

Go to the Web Console → Developer View
Switch to demo-app project
Click +Add → Use “Container Image”
Search for image like node:latest, php:8.2-apache, or quay.io/...

This gives visual understanding of how apps, builds, and deployments connect.

Step 5: Build from Source (Git to Deployment)

Deploy from Git (Node.js example):

oc new-app https://github.com/sclorg/nodejs-ex.git

Monitor:

oc get builds
oc logs -f bc/nodejs-ex

Access:

oc expose svc/nodejs-ex
oc get route

Step 6: Scale Applications

Increase Pods:

oc scale --replicas=3 deployment/nginx

Check Pods:

oc get pods -o wide

Step 7: Access Pod Shell & Logs

oc rsh <pod-name>
oc logs <pod-name>

Use this for debugging and viewing container state.

Step 8: Set Resource Limits

oc set resources deployment nginx \
  --limits=cpu=500m,memory=256Mi \
  --requests=cpu=200m,memory=128Mi

Step 9: Understand and Apply YAML

Export a deployment: oc get deployment nginx -o yaml > nginx.yaml
Edit and apply: oc apply -f nginx.yaml

Step 10: Use Secrets and ConfigMaps

Create ConfigMap:

oc create configmap app-config --from-literal=ENV=prod

Create Secret:

oc create secret generic app-secret --from-literal=DB_PASS=admin123

Mount or Inject via ENV in deployment YAML.

Step 11: OpenShift Pipelines (Tekton)

In OperatorHub, install OpenShift Pipelines Operator
Create:
- PipelineResource
- Task
- Pipeline
Use the developer console’s Pipelines view to build CI/CD

Step 12: Monitor with Web UI

Use Observe → Metrics
View Dashboard, Topology, and Builds
Use Pod terminal from console

Step 13: Delete a Project

oc delete project demo-app

Bonus Tips:

Feature	CLI Command
List all Pods	`oc get pods`
View events	`oc get events`
Port Forward	`oc port-forward svc/nginx 8080:80`
RoleBinding	`oc adm policy add-role-to-user admin developer`
Enable Dev View	Use toggle in OpenShift console UI

Practice Ideas:

Deploy a multi-container app with mysql + wordpress
Create blue-green deployments
Use Tekton pipeline to auto-deploy from GitHub

To deploy an image in OpenShift using the openshift/httpd image, and configure different Kubernetes resources such as StatefulSets, Secrets, ConfigMaps, CronJobs, Jobs, DaemonSets, and HPA, here are the YAML configurations and relevant commands for each.

1. Deployment (for basic deployment)

apiVersion: apps/v1
kind: Deployment
metadata:
  name: httpd-deployment
spec:
  replicas: 1
  selector:
    matchLabels:
      app: httpd
  template:
    metadata:
      labels:
        app: httpd
    spec:
      containers:
      - name: httpd
        image: openshift/httpd
        ports:
        - containerPort: 80

Command to deploy:

oc apply -f httpd-deployment.yaml

2. StatefulSet (for managing stateful workloads)

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: httpd-statefulset
spec:
  serviceName: "httpd"
  replicas: 3
  selector:
    matchLabels:
      app: httpd
  template:
    metadata:
      labels:
        app: httpd
    spec:
      containers:
      - name: httpd
        image: openshift/httpd
        ports:
        - containerPort: 80

Command to deploy:

oc apply -f httpd-statefulset.yaml

3. Secrets (for storing sensitive data like passwords)

apiVersion: v1
kind: Secret
metadata:
  name: httpd-secret
type: Opaque
data:
  password: cGFzc3dvcmQ=  # base64 encoded password

Command to create a secret:

oc apply -f httpd-secret.yaml

4. ConfigMap (for configuration files)

apiVersion: v1
kind: ConfigMap
metadata:
  name: httpd-config
data:
  httpd.conf: |
    ServerName localhost
    DocumentRoot /var/www/html

Command to create a config map:

oc apply -f httpd-config.yaml

5. CronJob (for scheduling periodic jobs)

apiVersion: batch/v1
kind: CronJob
metadata:
  name: httpd-cronjob
spec:
  schedule: "*/5 * * * *"  # Every 5 minutes
  jobTemplate:
    spec:
      template:
        spec:
          containers:
          - name: httpd
            image: openshift/httpd
          restartPolicy: OnFailure

Command to deploy a cron job:

oc apply -f httpd-cronjob.yaml

6. Job (for one-time tasks)

apiVersion: batch/v1
kind: Job
metadata:
  name: httpd-job
spec:
  template:
    spec:
      containers:
      - name: httpd
        image: openshift/httpd
      restartPolicy: Never

Command to deploy a job:

oc apply -f httpd-job.yaml

7. DaemonSet (for deploying a pod on every node)

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: httpd-daemonset
spec:
  selector:
    matchLabels:
      app: httpd
  template:
    metadata:
      labels:
        app: httpd
    spec:
      containers:
      - name: httpd
        image: openshift/httpd
        ports:
        - containerPort: 80

Command to deploy a daemon set:

oc apply -f httpd-daemonset.yaml

8. Horizontal Pod Autoscaler (HPA)

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: httpd-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: httpd-deployment
  minReplicas: 1
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50

Command to deploy HPA:

oc apply -f httpd-hpa.yaml

Summary of Commands

To deploy each of the above resources, use the following commands:

Deployment:
```
oc apply -f httpd-deployment.yaml
```
StatefulSet:
```
oc apply -f httpd-statefulset.yaml
```
Secrets:
```
oc apply -f httpd-secret.yaml
```
ConfigMap:
```
oc apply -f httpd-config.yaml
```
CronJob:
```
oc apply -f httpd-cronjob.yaml
```
Job:
```
oc apply -f httpd-job.yaml
```
DaemonSet:
```
oc apply -f httpd-daemonset.yaml
```
Horizontal Pod Autoscaler:
```
oc apply -f httpd-hpa.yaml
```

These YAML files and commands cover the most common Kubernetes resources you may need while deploying an image on OpenShift. Adjust the values (e.g., replicas, resources, image, etc.) as needed for your use case.

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Rajesh Kumar

I’m a DevOps/SRE/DevSecOps/Cloud Expert passionate about sharing knowledge and experiences. I am working at Cotocus. I blog tech insights at DevOps School, travel stories at Holiday Landmark, stock market tips at Stocks Mantra, health and fitness guidance at My Medic Plus, product reviews at I reviewed , and SEO strategies at Wizbrand.

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