Add e2e test for testing username / password authentication against a coupler.

tests/e2e_tests/test_beremiz.py

 import time
+import string
+import random
 from opcua import Client
 import slapos.testing.e2e as e2e
 
+# the OPC UA node of relay0 at I2C0 slave
+OPC_UA_IDENTIFIER = "ns=1;s=i2c0.relay0"
+
 class BeremizTest(e2e.EndToEndTestCase):
   """
   This tests check proper functioning with real instances (inside SlapOS cloud)
@@ -34,8 +39,8 @@ class BeremizTest(e2e.EndToEndTestCase):
     time.sleep(5*3600)
 
     print("Request beremiz-runtime and OSIE coupler instances.")
-    # supply / request coupler
-    instance_name = time.strftime('e2e-test-coupler-%Y-%B-%d-%H:%M:%S')
+    # supply / request coupler in anonymous mode (no user / pass)
+    instance_name = time.strftime('e2e-test-coupler-anonymous-%Y-%B-%d-%H:%M:%S')
     parameter_dict = {"mode":1}
     cls.request(cls.coupler_release,
                 instance_name,
@@ -45,6 +50,22 @@ class BeremizTest(e2e.EndToEndTestCase):
     print(connection_dict)
     cls.coupler_url_ipv6 = connection_dict.get("url-ipv6")
 
+    # supply / request coupler in authenticated mode (no user / pass)
+    cls.username = "admin"
+    cls.password = ''.join(random.choices(string.ascii_uppercase + string.digits, k=8))
+    instance_name = time.strftime('e2e-test-coupler-authenticated-%Y-%B-%d-%H:%M:%S')
+    parameter_dict = {"mode":1,
+                      "username": cls.username,
+                      "password": cls.password,
+                      "opc_ua_port": 5840}
+    cls.request(cls.coupler_release,
+                instance_name,
+                partition_parameter_kw=parameter_dict)
+    cls.waitUntilGreen(instance_name, 180)
+    connection_dict = cls.getInstanceInfos(instance_name).connection_dict
+    print(connection_dict)
+    cls.authenticated_coupler_url_ipv6 = connection_dict.get("url-ipv6")
+
     # supply / request beremiz-runtime
     instance_name = time.strftime('e2e-test-beremiz-runtime-%Y-%B-%d-%H:%M:%S')
     parameter_dict = {"runtime_plc_url": "https://lab.nexedi.com/nexedi/osie/raw/master/Beremiz/beremiz_test_opc_ua/bin/beremiz_test_opc_ua.tgz"}
@@ -55,10 +76,12 @@ class BeremizTest(e2e.EndToEndTestCase):
     connection_dict = cls.getInstanceInfos(instance_name).connection_dict
     print(connection_dict)
 
-  def test_plc_increment_run(self):
+  def test_01_plc_increment_run(self):
+    """
+    Test that beremiz-runtime can control over OPC UA a slave coupler by incrementing a counter.
+    """
     NUMBER_OF_CHECKS = 100
     TIMEOUT = 3
-    OPC_UA_IDENTIFIER = "ns=1;s=i2c0.relay0"
 
     # give it some time for services(runtime & coupler) to warm up, connect and run
     time.sleep(30)
@@ -90,3 +113,22 @@ class BeremizTest(e2e.EndToEndTestCase):
       client.disconnect()
     # no failures
     self.assertEqual(test_failures, 0)
+
+  def test_02_username_password_authentication_coupler(self):
+    """
+    Test username / password authentication for coupler.
+    """
+    try:
+        # connect to a session at OPC-UA server
+        client = Client(self.authenticated_coupler_url_ipv6)
+        client.set_user(self.username)
+        client.set_password(self.password)
+        client.connect()
+        root = client.get_root_node()
+        children_list = root.get_children()
+        var = client.get_node(OPC_UA_IDENTIFIER)
+        # by default it is a 0
+        self.assertEqual(var.get_value(), 0)
+        print(var.get_value())
+    finally:
+        client.disconnect()