set up simple unit test

e2e/tests.py

@@ -1,23 +1,54 @@
 #!/usr/bin/env python3
 
+import unittest
 from kubernetes import client, config
+from pprint import pprint
 
-def main():
+class SampleTestCase(unittest.TestCase):
 
-    config.load_kube_config()
-    v1 = client.CoreV1Api()
+    nodes = set(["kind-test-postgres-operator-worker", "kind-test-postgres-operator-worker2", "kind-test-postgres-operator-worker3"])
 
+    def setUp(self):
+        self.config = config.load_kube_config()
+        self.v1 = client.CoreV1Api()
+
+    def test_assign_labels_to_nodes(self):
+        """
+           Ensure labeling nodes through the externally connected Python client works.
+           Sample test case to illustrate potential test structure
+        """
         body = {
             "metadata": {
                 "labels": {
-                "lifecycle-status": "ready",
+                    "lifecycle-status": "ready"
                  }
             }
         }
+        for node in self.nodes:
+            _ = self.v1.patch_node(node, body)
 
-    nodes = ["kind-test-postgres-operator-worker", "kind-test-postgres-operator-worker2", "kind-test-postgres-operator-worker3"]
-    for node in nodes:
-        _ = v1.patch_node(node, body)
+        labelled_nodes = set([])
+        for node in self.nodes:
+            v1_node_var = self.v1.read_node(node)
+            if v1_node_var.metadata.labels['lifecycle-status'] == 'ready':
+                labelled_nodes.add(v1_node_var.metadata.name)
+
+        assert self.nodes == labelled_nodes, "nodes incorrectly labelled"
+
+    def tearDown(self):
+        """
+           Each test must restore the original cluster state
+           to avoid introducing dependencies between tests
+        """
+        body = {
+            "metadata": {
+                "labels": {
+                    "lifecycle-status": None # deletes label
+                 }
+            }
+        }
+        for node in self.nodes:
+            _ = self.v1.patch_node(node, body)
 
 if __name__ == '__main__':
-    main()
+    unittest.main()