Create cross namespace secrets (#1490)

* Create cross namespace secrets

* add test cases

* fixes

* Fixes
- include namespace in secret name only when namespace is provided
- use username.namespace as key to pgUsers only when namespace is
  provided
- avoid conflict in the role creation in db by checking namespace
  alongwith the username

* Update unit tests

* Fix test case

* Fixes

- update regular expression for usernames
- add test to allow check for valid usernames
- create pg roles with namespace (if any) appended in rolename

* add more test cases for valid usernames

* update docs

* fixes as per review comments

* update e2e

* fixes

* Add toggle to allow namespaced secrets

* update docs

* comment update

* Update e2e/tests/test_e2e.py

* few minor fixes

* fix unit tests

* fix e2e

* fix e2e attempt 2

* fix e2e

Co-authored-by: Rafia Sabih <rafia.sabih@zalando.de>
Co-authored-by: Felix Kunde <felix-kunde@gmx.de>

e2e/tests/k8s_api.py

@@ -197,6 +197,16 @@ class K8s:
                 pod_phase = pods[0].status.phase
             time.sleep(self.RETRY_TIMEOUT_SEC)
 
+    def wait_for_namespace_creation(self, namespace='default'):
+        ns_found = False
+        while ns_found != True:
+            ns = self.api.core_v1.list_namespace().items
+            for n in ns:
+                if n.metadata.name == namespace:
+                    ns_found = True
+                    break
+            time.sleep(self.RETRY_TIMEOUT_SEC)
+
     def get_logical_backup_job(self, namespace='default'):
         return self.api.batch_v1_beta1.list_namespaced_cron_job(namespace, label_selector="application=spilo")