Hello Openshift!

This repo is based on the work done by Paul Bouwer's hello-kubernetes project.

This image can be deployed on a Opennshift cluster. It displays:

a default Hello world! message
the pod name
node os information

The default "Hello world!" message displayed can be overridden using the MESSAGE environment variable.

The default port of 8080 can be overriden using the PORT environment variable.

DockerHub

It is available on DockerHub as:

akilada/hello-openshift:0.1

Deploy

You can deploy the image to your Kubernetes cluster one of two ways:

Deploy using the hello-kubernetes.yaml, which contains definitions for the service and deployment objects:

# hello-openshift.yaml

apiVersion: v1
kind: Service
metadata:
  name: hello-openshift
spec:
  type: ClusterIP
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: hello-openshift
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-openshift
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello-openshift
  template:
    metadata:
      labels:
        app: hello-openshift
    spec:
      containers:
      - name: hello-openshift
        image: akilada/hello-openshift:0.1
        ports:
        - containerPort: 8080

$ oc apply -f yaml/hello-openshift.yaml -n <namespace>

This will display a Hello world! message when you hit the service endpoint in a browser. You can get the service endpoint ip address by executing the following command and grabbing the returned external ip address value:

$ oc get service hello-openshift

Custom Message

You can customise the message displayed by the hello-openshift container as follows:

Deploy using the hello-opennshift.custom-message.yaml, which contains definitions for the service and deployment objects:

In the definition for the deployment, add an env variable with the name of MESSAGE. The value you provide will be displayed as the custom message.

# hello-openshift.custom-message.yaml

apiVersion: v1
kind: Service
metadata:
  name: hello-openshift-custom
spec:
  type: ClusterIP
  ports:
  - port: 80
    targetPort: 8080
  selector:
    app: hello-openshift-custom
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-openshift-custom
spec:
  replicas: 1
  selector:
    matchLabels:
      app: hello-openshift-custom
  template:
    metadata:
      labels:
        app: hello-openshift-custom
    spec:
      containers:
      - name: hello-openshift
        image: akilada/hello-openshift:0.1
        ports:
        - containerPort: 8080
        env:
        - name: MESSAGE
          value: I just deployed this on Openshift!

$ oc apply -f yaml/hello-openshift.custom-message.yaml

Custom Port

By default, the hello-openshift app listens on port 8080. If you have a requirement for the app to listen on another port, you can specify the port via an env variable with the name of PORT. Remember to also update the containers.ports.containerPort value to match.

Here is an example:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: hello-openshift-custom
spec:
  replicas: 3
  selector:
    matchLabels:
      app: hello-openshift-custom
  template:
    metadata:
      labels:
        app: hello-openshift-custom
    spec:
      containers:
      - name: hello-openshift
        image: akilada/hello-openshift:0.1
        ports:
        - containerPort: 80
        env:
        - name: PORT
          value: "80"

This repo is inspired by the work done by Paul Bouwer.