Moved content for Retriggering integration tests for upstream

Author: gtrivedi88

docs/modules/ROOT/pages/how-tos/testing/integration/rerunning.adoc

@@ -1 +1,57 @@
-= Rerunning an integration test
+= Retriggering Integration Tests
+
+Integration test scenarios for a given snapshot can be re-triggered by adding a label to the snapshot.
+
+.Prerequisites
+- You have a snapshot that has completed all its initial tests. All initial tests must be finished before you trigger subsequent tests.
+
+- The snapshot for which tests will be retriggered has completed its initial tests.
+
+- You have CLI access to the specific OpenShift cluster. For information on obtaining CLI access, refer Getting started.
+
+- You have an up-to-date kubectl binary.  Alternatively, the `oc` binary is also compatible.
+
+.Procedure
+
+. Identify the IntegrationTestScenario that needs to be rerun.  For a given snapshot, you can only rerun one IntegrationTestScenario.
+
+. Label the snapshot with `test.appstudio.openshift.io/run`, assigning the scenario name you wish to rerun as its value.
+
++
+[source]
+----
+$ kubectl label snapshot [snapshot name] test.appstudio.openshift.io/run=[scenario name]
+----
+
+. The tests are re-triggered automatically.  Once they are re-triggered, the system removes the label, allowing you to apply a new label for a different scenario if you wish to test multiple scenarios.
+
++
+[source]
+----
+$ tkn pipelinerun list
+
+[Example Output]
+NAME                            STARTED         DURATION   STATUS
+integration-pipelinerun-jfrdb   4 seconds ago   ---        Running
+----
+
+.Verification
+
+. To verify the tests, run `tkn pipelinerun describe [pipelinerun]` and ensure that the labels `appstudio.openshift.io/snapshot` and `test.appstudio.openshift.io/scenario` reference the correct snapshot and scenario.
+
++
+[source]
+----
+$ tkn pipelinerun describe integration-pipelinerun-jfrdb
+
+[Expected labels in the output]
+Name:              integration-pipelinerun-jfrdb
+Namespace:         default
+Service Account:   appstudio-pipeline
+Labels:
+...
+ appstudio.openshift.io/snapshot=snapshot-sample
+...
+ test.appstudio.openshift.io/test=component
+...
+----