#**Lab 11: Rollback Applications** In this lab we will see how we can rollback an application in OpenShift quickly without switching to an older version of the source code in SCM. We will: 1. Use the same app we deployed in Lab 10. If you haven't, please complete that Lab first. 2. Rollback the application using the OpenShift v3 command "rollback" **Step 1: Check application health status** Run: $ oc get pods NAME READY STATUS RESTARTS AGE scm-web-hooks-1-build 0/1 Completed 0 4m scm-web-hooks-2-build 0/1 Completed 0 1m scm-web-hooks-3-4ai3m 1/1 Running 0 40s scm-web-hooks-3-build 0/1 Completed 0 1m Inspecting the output of the above command we can see that we have a single replica of the previously deployed application running. We can also see that previously three pods were used to build the application. OpenShift will create and docker deploy a pod per deployment. This tells us that we currently have two versions of the application. You can also use: $ oc get dc NAME TRIGGERS LATEST scm-web-hooks ConfigChange, ImageChange 3 The latest and active version for the application is **3** If we display the application in the browser we see:  **Step 2: Rollback the application** Using the previous command we ran to retrieve the deployment configuration, we will revert or rollback to version 1. $ oc rollback scm-web-hooks --to-version=1 #4 rolled back to scm-web-hooks-1 If we re-run the command to list the build configurations, we now see: $ oc get dc NAME TRIGGERS LATEST VERSION scm-web-hooks ConfigChange, ImageChange 4 So OpenShift has rolled back the application to version 1 and created a new build configuration. Reloading the application now displays:  ## Summary We have seen that rolling back to previous deployments is easy when using immutable container based deployments that are versioned