Lab Objective

In this lab, you will deploy an application on OpenShift from an existing container image.

This lab is different from building an application from source code. In the previous source-code lab, OpenShift pulled code from Git and built a container image. In this lab, the container image already exists in an external container registry, so OpenShift only needs to pull the image and run it.

By the end of this lab, you will understand how OpenShift deploys a ready-made container image using the web console.

What You Will Learn

You will learn how to:

1. Start OpenShift Local.
2. Log in to the OpenShift web console.
3. Create a new project.
4. Deploy an application from an external container image.
5. Use the OpenShift web console Container images option.
6. Create a Deployment.
7. Create a Service.
8. Create a Route.
9. Open the application in a browser.
10. Validate the deployment using the oc CLI.
11. Inspect pods, services, routes, labels, and logs.
12. Scale the application.
13. Troubleshoot common image deployment issues.
14. Clean up the lab environment.

Lab Scenario

You already have a container image stored in a registry.

You want to run that image on OpenShift without building source code.

For this lab, you will use the following public sample image:

quay.io/openshiftroadshow/parksmap:latest

This image is used in Red Hat’s OpenShift learning material as a sample front-end application.

Lab Architecture

External Container Registry
        |
        v
OpenShift pulls image
        |
        v
Deployment
        |
        v
ReplicaSet
        |
        v
Pod
        |
        v
Service
        |
        v
Route
        |
        v
Browser

Key Difference: Source Code Build vs Container Image Deployment

OpenShift Resources Created in This Lab

When you deploy from a container image, OpenShift creates these resources:

Unlike a source-code build lab, this lab does not create a BuildConfig or Build, because no build is needed.

Part 1: Prerequisites

Required Tools

You need:

1. OpenShift Local installed.
2. crc command available.
3. oc command available.
4. Browser access to the OpenShift web console.
5. Internet access from OpenShift Local to pull the container image.

Recommended Local Machine Resources

Use at least:

Part 2: Start OpenShift Local

Open a terminal.

Check CRC version:

crc version

Set the OpenShift preset:

crc config set preset openshift
Code language: JavaScript (javascript)

Run setup:

crc setup

Start OpenShift Local:

crc start

The startup may take several minutes.

To view the OpenShift Local credentials:

crc console --credentials
Code language: JavaScript (javascript)

To open the web console:

crc console
Code language: JavaScript (javascript)

Part 3: Configure the oc CLI

Run:

crc oc-env

On Linux or macOS, run:

eval $(crc oc-env)
Code language: JavaScript (javascript)

On Windows PowerShell, copy and run the command printed by crc oc-env.

Log in as the developer user:

oc login -u developer https://api.crc.testing:6443
Code language: JavaScript (javascript)

Use the password from:

crc console --credentials
Code language: JavaScript (javascript)

Verify login:

oc whoami

Expected output:

developer

Check the node:

oc get nodes
Code language: JavaScript (javascript)

Expected output should show one OpenShift Local node in Ready status.

Part 4: Create a New Project

Option A: Create Project from Web Console

1. Open the OpenShift web console.
2. Log in as developer.
3. Switch to the Developer perspective.
4. Click the Project dropdown.
5. Click Create Project.
6. Enter:

lab12-container-image

7. Optional display name:

Lab 12 Container Image

8. Click Create.

Option B: Create Project from CLI

Run:

oc new-project lab12-container-image
Code language: JavaScript (javascript)

Verify:

oc project

Expected output:

Using project "lab12-container-image"
Code language: JavaScript (javascript)

Part 5: Deploy the Application from a Container Image

In the OpenShift web console:

1. Make sure you are in the project:

lab12-container-image

2. Switch to the Developer perspective.
3. Click +Add.
4. Click Container images.

Depending on your OpenShift version, you may also see this from the quick-create + icon.

Image Section

Select:

Image name from external registry
Code language: JavaScript (javascript)

In the image name field, enter:

quay.io/openshiftroadshow/parksmap:latest

OpenShift will validate the image.

If validation takes time, wait for a few seconds.

Runtime Icon

For the runtime icon, you can select a suitable icon such as:

Java

or keep the default detected icon.

The icon does not affect the deployment. It only changes how the workload appears in the Topology view.

Part 6: Configure General Settings

Scroll to the General section.

Use these values:

Enter:

Application name: national-parks-app
Name: parksmap

The Application name groups related components visually in the Topology view.

The Name is used for the actual OpenShift resources such as Deployment, Service, and Route.

Part 7: Select Resource Type

In the Resource type section, select:

Deployment

Do not select DeploymentConfig.

A Deployment is the standard Kubernetes workload resource and is the best option for current beginner labs.

Part 8: Create a Route

In the Advanced options section, make sure this is enabled:

Create a route to the application

A Route is required because this is a web application and students need to open it in a browser.

Without a Route, the application would run inside the cluster, but it would not be accessible from your browser.

Part 9: Add Labels

Click the Labels section.

Add the following labels:

app=national-parks-app
component=parksmap
role=frontend

These labels help organize the application and make it easier to identify resources.

They are also useful for selectors, filtering, and the Topology view.

Part 10: Create the Application

Review your configuration.

Click:

Create

OpenShift now creates the application.

Because this lab uses an existing image, there is no build step.

Part 11: Watch the Application in Topology

After clicking Create, OpenShift redirects you to the Topology view.

You should see a workload named:

parksmap

Wait until the workload shows as running.

Click the parksmap workload.

You should see tabs or sections such as:

1. Details
2. Resources
3. Observe
4. Logs

The exact layout may vary slightly by OpenShift version.

Part 12: Open the Application in a Browser

In the Topology view:

1. Click the parksmap workload.
2. Click the external URL or open-route icon.
3. A browser tab should open.

You should see the ParksMap web application page.

If the page does not load immediately, wait for the pod to become ready and refresh the browser.

Part 13: Validate the Deployment Using CLI

Set the project:

oc project lab12-container-image

List all created resources:

oc get all
Code language: JavaScript (javascript)

Expected resources include:

deployment.apps/parksmap
replicaset.apps/parksmap-xxxxx
pod/parksmap-xxxxx
service/parksmap
route.route.openshift.io/parksmap

List only the important resources:

oc get deployment,pod,svc,route
Code language: JavaScript (javascript)

Expected output should show:

deployment.apps/parksmap
pod/parksmap-xxxxx
service/parksmap
route.route.openshift.io/parksmap

Part 14: Check the Deployment

Run:

oc get deployment parksmap
Code language: JavaScript (javascript)

Expected output:

NAME       READY   UP-TO-DATE   AVAILABLE   AGE
parksmap   1/1     1            1           ...

Check rollout status:

oc rollout status deployment/parksmap

Expected output:

deployment "parksmap" successfully rolled out
Code language: JavaScript (javascript)

Describe the Deployment:

oc describe deployment parksmap

Check the image used by the Deployment:

oc get deployment parksmap -o jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'
Code language: PHP (php)

Expected output:

quay.io/openshiftroadshow/parksmap:latest

Part 15: Check the Pod

Run:

oc get pods
Code language: JavaScript (javascript)

Expected output:

NAME                        READY   STATUS    RESTARTS   AGE
parksmap-xxxxxxxxxx-xxxxx   1/1     Running   0          ...

View pod logs:

oc logs deployment/parksmap

If the pod is not running, describe it:

oc describe pod -l deployment=parksmap

If that selector does not work in your environment, list labels first:

oc get pods --show-labels
Code language: JavaScript (javascript)

Then use the correct label shown in your output.

Part 16: Check the Service

Run:

oc get svc parksmap
Code language: JavaScript (javascript)

Expected output:

NAME       TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)    AGE
parksmap   ClusterIP   ...             <none>        8080/TCP   ...
Code language: HTML, XML (xml)

The Service provides internal cluster access to the application.

Inside the same OpenShift project, other pods can reach this app using:

http://parksmap:8080
Code language: JavaScript (javascript)

Describe the Service:

oc describe svc parksmap

Check endpoints:

oc get endpoints parksmap
Code language: JavaScript (javascript)

The endpoint should point to the running pod IP and port.

If the endpoint is empty, the Service is not matching the pod labels.

Part 17: Check the Route

Run:

oc get route parksmap
Code language: JavaScript (javascript)

Expected output:

NAME       HOST/PORT                                             SERVICES   PORT
parksmap   parksmap-lab12-container-image.apps-crc.testing       parksmap   8080

The exact hostname may be different.

Store the app URL:

APP_URL="http://$(oc get route parksmap -o jsonpath='{.spec.host}')"
echo "$APP_URL"
Code language: PHP (php)

Test the route:

curl -I "$APP_URL"
Code language: JavaScript (javascript)

Expected result:

HTTP/1.1 200 OK
Code language: HTTP (http)

A different successful HTTP response is also acceptable, depending on the image behavior.

Part 18: Confirm That No Build Was Created

This lab deploys an existing image. It does not build a new image.

Check BuildConfigs:

oc get buildconfig
Code language: JavaScript (javascript)

Expected output:

No resources found in lab12-container-image namespace.
Code language: PHP (php)

Check Builds:

oc get builds
Code language: JavaScript (javascript)

Expected output:

No resources found in lab12-container-image namespace.
Code language: PHP (php)

This is correct.

No BuildConfig is needed because the container image already exists.

Part 19: Scale the Application

You can scale the Deployment from the web console or CLI.

Option A: Scale from Web Console

1. Go to Developer perspective.
2. Open Topology.
3. Click the parksmap workload.
4. Open the Details tab.
5. Increase the pod count from 1 to 2.

Wait until two pods are running.

Option B: Scale from CLI

Run:

oc scale deployment/parksmap --replicas=2

Check pods:

oc get pods
Code language: JavaScript (javascript)

Expected result:

Two parksmap pods should be running.

Check Deployment:

oc get deployment parksmap
Code language: JavaScript (javascript)

Expected output:

READY   2/2

Scale back to one pod:

oc scale deployment/parksmap --replicas=1

Verify:

oc get deployment parksmap
Code language: JavaScript (javascript)

Expected output:

READY   1/1

Part 20: Update the Container Image Tag

In real projects, teams often deploy a new application version by changing the image tag.

For this beginner lab, do not change the image unless your instructor provides a tested tag.

You can view the current image:

oc get deployment parksmap -o jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'
Code language: PHP (php)

Example output:

quay.io/openshiftroadshow/parksmap:latest

If you had another valid image tag, the update command would look like this:

oc set image deployment/parksmap parksmap=quay.io/openshiftroadshow/parksmap:<new-tag>
Code language: HTML, XML (xml)

Then check rollout:

oc rollout status deployment/parksmap

For this lab, keep the original image.

Part 21: Roll Out Restart

You can restart the application without changing the image.

Run:

oc rollout restart deployment/parksmap

Watch rollout:

oc rollout status deployment/parksmap

Check pods:

oc get pods
Code language: JavaScript (javascript)

You should see a new pod replacing the old pod.

Part 22: Student Checkpoint

Students should be able to answer:

Part 23: Full Validation Script

Run this after completing the lab:

oc project lab12-container-image

echo "Checking Deployment..."
oc get deployment parksmap

echo "Checking rollout..."
oc rollout status deployment/parksmap

echo "Checking pods..."
oc get pods -o wide

echo "Checking image..."
oc get deployment parksmap -o jsonpath='{.spec.template.spec.containers[0].image}{"\n"}'

echo "Checking service..."
oc get svc parksmap

echo "Checking endpoints..."
oc get endpoints parksmap

echo "Checking route..."
oc get route parksmap

echo "Checking that no build exists..."
oc get bc
oc get builds

echo "Testing application route..."
APP_URL="http://$(oc get route parksmap -o jsonpath='{.spec.host}')"
echo "$APP_URL"
curl -I "$APP_URL"
Code language: PHP (php)

Expected result:

1. Deployment is available.
2. Pod is running.
3. Service exists.
4. Endpoint exists.
5. Route exists.
6. No BuildConfig exists.
7. No Build exists.
8. Browser URL works.

Part 24: Troubleshooting

Problem 1: ImagePullBackOff

Symptom

The pod is not running and shows:

ImagePullBackOff

or:

ErrImagePull

Check

Run:

oc get pods
Code language: JavaScript (javascript)

Describe the pod:

oc describe pod -l app=parksmap

If that selector does not work, run:

oc get pods --show-labels
Code language: JavaScript (javascript)

Then describe the pod by name:

oc describe pod <pod-name>
Code language: HTML, XML (xml)

Common Causes

1. Wrong image name.
2. Registry is temporarily unavailable.
3. OpenShift Local cannot reach the registry.
4. Image is private and needs a pull secret.
5. VPN or firewall is blocking registry access.

Fix

Verify the image name:

quay.io/openshiftroadshow/parksmap:latest

Check CRC status:

crc status

If using VPN, disconnect VPN and retry if possible.

Restart the rollout:

oc rollout restart deployment/parksmap

Problem 2: Route Does Not Open

Symptom

The pod is running, but the browser page does not open.

Check

Run:

oc get route parksmap
Code language: JavaScript (javascript)

Check service:

oc get svc parksmap
Code language: JavaScript (javascript)

Check endpoints:

oc get endpoints parksmap
Code language: JavaScript (javascript)

If endpoints are empty, the Service is not pointing to the pod.

Check pod labels:

oc get pods --show-labels
Code language: JavaScript (javascript)

Check Service selector:

oc describe svc parksmap

The Service selector must match the pod labels.

Problem 3: Pod Is Running but App Is Not Responding

Check logs:

oc logs deployment/parksmap

Check pod status:

oc describe deployment parksmap

Check whether the Service has endpoints:

oc get endpoints parksmap
Code language: JavaScript (javascript)

If the application listens on a different port than the Service expects, the route may fail.

For this lab, the parksmap image is expected to expose the application through port 8080.

Problem 4: No Route Was Created

If you forgot to enable Create a route, create the Route manually:

oc expose svc/parksmap

Verify:

oc get route parksmap
Code language: JavaScript (javascript)

Open the route again.

Problem 5: BuildConfig Not Found

This is not an error.

This lab deploys an existing image.

So this output is expected:

oc get bc
Code language: JavaScript (javascript)

Expected:

No resources found

A BuildConfig is only needed when OpenShift builds an image from source code or binary input.

Problem 6: Application Works in Browser but curl Fails

Possible causes:

1. Local DNS issue.
2. Browser has a working DNS/proxy setup but terminal does not.
3. VPN or firewall issue.
4. CRC networking issue.

Check CRC:

crc status

Print the route:

oc get route parksmap
Code language: JavaScript (javascript)

Try again after a minute.

Part 25: Optional CLI-Only Equivalent

The main purpose of this lab is to use the web console.

However, the equivalent CLI workflow is useful to know.

Create a new project:

oc new-project lab12-container-image-cli
Code language: JavaScript (javascript)

Create the application from image:

oc new-app quay.io/openshiftroadshow/parksmap:latest --name=parksmap
Code language: JavaScript (javascript)

Expose the Service:

oc expose svc/parksmap

Check resources:

oc get deployment,pod,svc,route
Code language: JavaScript (javascript)

Test the route:

APP_URL="http://$(oc get route parksmap -o jsonpath='{.spec.host}')"
curl -I "$APP_URL"
Code language: JavaScript (javascript)

Clean up the CLI test project:

oc delete project lab12-container-image-cli
Code language: JavaScript (javascript)

Part 26: Cleanup

Cleanup from Web Console

1. Go to the Developer perspective.
2. Select project:

lab12-container-image

3. Go to Topology.
4. Open the action menu for the parksmap application.
5. Click Delete Application.
6. Confirm deletion.

This deletes the application resources.

Cleanup from CLI

The easiest cleanup is to delete the whole project:

oc delete project lab12-container-image
Code language: JavaScript (javascript)

Verify:

oc get project lab12-container-image
Code language: JavaScript (javascript)

Expected output:

Error from server (NotFound): projects.project.openshift.io "lab12-container-image" not found
Code language: JavaScript (javascript)

Part 27: Lab Summary

In this lab, you deployed an application from an existing container image using the OpenShift web console.

You learned that:

1. Container images can be deployed directly without building source code.
2. The Container images option is used when an image already exists in a registry.
3. A Deployment runs the application.
4. A Pod runs the actual container.
5. A Service provides internal access.
6. A Route provides external browser access.
7. No BuildConfig or Build is created when deploying an existing image.
8. OpenShift can scale and restart the application using Deployment features.

Part 28: Review Questions

Question 1

What was the input for this lab?

Answer

An existing container image:

quay.io/openshiftroadshow/parksmap:latest

Question 2

Did OpenShift build a new image in this lab?

Answer

No. OpenShift pulled and ran an existing image.

Question 3

Which OpenShift web-console option did we use?

Answer

+Add -> Container images

Question 4

Which resource runs the application?

Answer

Deployment.

Question 5

Which resource exposes the application inside the cluster?

Answer

Service.

Question 6

Which resource exposes the application outside the cluster?

Answer

Route.

Question 7

Why was no BuildConfig created?

Answer

Because OpenShift did not build source code. It deployed an image that already existed.

Question 8

What command checks the Deployment status?

Answer

oc rollout status deployment/parksmap

Question 9

What command shows the Route?

Answer

oc get route parksmap
Code language: JavaScript (javascript)

Question 10

What command deletes the full lab project?

Answer

oc delete project lab12-container-image
Code language: JavaScript (javascript)

Instructor Notes

This lab is designed as a replacement for the older short article about deploying an application from a container image.

The old article’s topic is correct, but the replacement lab improves it by:

1. Using OpenShift Local instead of Developer Sandbox.
2. Using an official OpenShift sample image.
3. Separating this lab from the Git/source-code workflow.
4. Using Deployment instead of DeploymentConfig.
5. Adding route, service, pod, and deployment validation.
6. Explaining why no BuildConfig is created.
7. Adding CLI checks.
8. Adding troubleshooting.
9. Adding cleanup steps.

For production or advanced courses, add follow-up labs for:

1. Deploying images from a private registry.
2. Creating image pull secrets.
3. Deploying from an internal OpenShift ImageStream.
4. Updating images by tag and digest.
5. Using immutable image digests instead of latest.
6. Image vulnerability scanning.
7. Image signing and verification.
8. GitOps-based image deployment.
9. Rollback and rollout history.
10. Resource requests and limits.

Instructor Pre-Validation Checklist

Before delivering this lab to students, run:

crc status
oc whoami
oc get nodes
Code language: JavaScript (javascript)

Create a quick test project:

oc new-project lab12-test
Code language: JavaScript (javascript)

Deploy the sample image:

oc new-app quay.io/openshiftroadshow/parksmap:latest --name=parksmap
Code language: JavaScript (javascript)

Expose it:

oc expose svc/parksmap

Validate:

oc rollout status deployment/parksmap
oc get pod,svc,route
APP_URL="http://$(oc get route parksmap -o jsonpath='{.spec.host}')"
curl -I "$APP_URL"
Code language: PHP (php)

Clean up:

oc delete project lab12-test
Code language: JavaScript (javascript)

If these commands pass, the lab is ready for students.

Final Outcome

You have successfully deployed an application from an existing container image using the OpenShift web console.

You now understand this workflow:

Container Image
  -> Deployment
  -> Pod
  -> Service
  -> Route
  -> Browser

This is one of the most common real-world OpenShift workflows because many teams build images in CI/CD pipelines and then deploy those already-built images into OpenShift.

Rajesh Kumar

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