Update e2e pipeline (#1202)

* clean up after test_multi_namespace test

* see the PR description for complete list of changes

Co-authored-by: Sergey Dudoladov <sergey.dudoladov@zalando.de>

e2e/README.md

@@ -56,12 +56,24 @@ NOCLEANUP=True ./run.sh main tests.test_e2e.EndToEndTestCase.test_lazy_spilo_upg
 
 ## Inspecting Kind
 
-If you want to inspect Kind/Kubernetes cluster, use the following script to exec into the K8s setup and then use `kubectl`
+If you want to inspect Kind/Kubernetes cluster, switch `kubeconfig` file and context
+```bash
+# save the old config in case you have it
+export KUBECONFIG_SAVED=$KUBECONFIG
+
+# use the one created by e2e tests
+export KUBECONFIG=/tmp/kind-config-postgres-operator-e2e-tests
+
+# this kubeconfig defines a single context
+kubectl config use-context kind-postgres-operator-e2e-tests
+```
+
+or use the following script to exec into the K8s setup and then use `kubectl`
 
 ```bash
 ./exec_into_env.sh
 
-# use kube ctl
+# use kubectl
 kubectl get pods
 
 # watch relevant objects
@@ -71,6 +83,14 @@ kubectl get pods
 ./scripts/get_logs.sh
 ```
 
+If you want to inspect the state of the `kind` cluster manually with a single command, add a `context` flag
+```bash
+kubectl get pods --context kind-kind
+```
+or set the context for a few commands at once
+
+
+
 ## Cleaning up Kind
 
 To cleanup kind and start fresh
@@ -79,6 +99,12 @@ To cleanup kind and start fresh
 e2e/run.sh cleanup
 ```
 
+That also helps in case you see the
+```
+ERROR: no nodes found for cluster "postgres-operator-e2e-tests"
+```
+that happens when the `kind` cluster was deleted manually but its configuraiton file was not.
+
 ## Covered use cases
 
 The current tests are all bundled in [`test_e2e.py`](tests/test_e2e.py):