In this lab you will learn how to create a new project on OpenShift and how to create an application from an existing docker image.
Step 1: Add a new project from command line
Note: Please replace UserName with the username assigned to you in the commands below.
$ oc new-project mycliproject-UserName --description="My CLI Project" --display-name="CLI Project"
Upon project creation, OpenShift will automatically switch to the newly created project/namespace. If you wish to view the list of projects, run the following command:
$ oc get projects
If you have more than one project, you can switch to a different one by issuing oc project <project name>. Although you don't want to do it now.
You can also check the status of the project by running the following command. It says that the project is currently not running anything.
$ oc status
In project CLI Project (mycliproject-UserName)
You have no services, deployment configs, or build configs.
Run 'oc new-app' to create an application.
Step 2: Create an application from a Docker Image
Next we will create an application inside the above project using an existing docker image. We will be using a very simple docker image on dockerhub that just says "Welcome to OpenShift V3". Let us just use that for this exercise.
First create a new application using the docker image using the oc new-app command as shown below:
$ oc new-app redhatworkshops/welcome-php --name=welcome
--> Found Docker image f001b13 (8 months old) from Docker Hub for "redhatworkshops/welcome-php"
* An image stream will be created as "welcome:latest" that will track this image
* This image will be deployed in deployment config "welcome"
* Port 8080/tcp will be load balanced by service "welcome"
* Other containers can access this service through the hostname "welcome"
* WARNING: Image "redhatworkshops/welcome-php" runs as the 'root' user which may not be permitted by your cluster administrator
--> Creating resources with label app=welcome ...
imagestream "welcome" created
deploymentconfig "welcome" created
service "welcome" created
--> Success
Run 'oc status' to view your app.
The above command uses the docker image to deploy a docker container in a pod. If you quickly run oc get pods you will notice that a deployer pod runs and it starts an application pod as shown below.
$ oc get pods
NAME READY STATUS RESTARTS AGE
welcome-1-deploy 1/1 Running 0 1m
welcome-1-dkyyq 0/1 Pending 0 0s
In the above example welcome-1-deploy is the deployer pod and the other one is the actual application pod. In a little while the deployer pod will succeed and the application pod will change for Pending to Running status.
$ oc get pods
NAME READY STATUS RESTARTS AGE
welcome-1-dkyyq 1/1 Running 0 56s
Step 3: Add a Route for your application
OpenShift also spins up a service for this application. Run the following command to view the list of services in the project.
$ oc get services
NAME CLUSTER-IP EXTERNAL-IP PORT(S) AGE
welcome 172.30.77.93 <none> 8080/TCP 2m
You will notice the welcome service was created for this project.
However, there is no route for this application yet. So you cannot access this application from outside.
Now add a route to the service with the following command. oc expose command will allow you to expose your service to the world so that you can access it from the browser.
$ oc expose service welcome
$ oc get route
NAME HOST/PORT PATH SERVICE LABELS
welcome welcome-mycliproject-user02.apps.ose3sandbox.com welcome
Step 4: Try your application
Access the application: Now access the application using curl (looking for 200 status code) or from the browser and see the result
$ curl -Is http://welcome-mycliproject-UserName.apps.ose3sandbox.com
Voila!! you created your first application using an existing docker image on OpenShift.
Step 4: Clean up
Run the oc get all command to view all the components that were created in your project.
$ oc get all
NAME TYPE SOURCE
NAME TYPE STATUS POD
NAME DOCKER REPO TAGS UPDATED
welcome redhatworkshops/welcome-php latest 5 hours ago
NAME TRIGGERS LATEST VERSION
welcome ConfigChange, ImageChange 1
CONTROLLER CONTAINER(S) IMAGE(S) SELECTOR REPLICAS
welcome-1 welcome redhatworkshops/welcome-php:latest deployment=welcome-1,deploymentconfig=welcome 1
NAME HOST/PORT PATH SERVICE LABELS
welcome welcome.apps.osecloud.com welcome
NAME LABELS SELECTOR IP(S) PORT(S)
welcome <none> deploymentconfig=welcome 172.30.155.37 80/TCP
NAME READY REASON RESTARTS AGE
welcome-1-8d7nk 1/1 Running 0 4h
Now you can delete all these components by running one command.
$ oc delete all -l app=welcome
imagestream "welcome" deleted
deploymentconfig "welcome" deleted
route "welcome" deleted
service "welcome" deleted
pod "welcome-1-ynedb" deleted
You will notice that it has deleted the imagestream for the application, the deploymentconfig, the service and the route.
You can run oc get all again to make sure the project is empty.
Congratulations!! You now know how to create a project, an application using an external docker image and navigate around. Get ready for more fun stuff!