integration_tests: use unique MAC addresses for tests (#813)

Using the same MAC address results in strange test behaviour if more
than one such instance is up: traffic gets routed to an arbitrary
interface with the given MAC address.  This can happen if running tests
in parallel, or on a system which retains test instances from previous
runs.

The introduction of tests/integration_tests/__init__.py means that
pylint now checks the integration tests: this commit also addresses
those failures.

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/integration_tests/__init__.py b/tests/integration_tests/__init__.py
new file mode 100644
index 00000000..e1d4cd28
--- /dev/null
+++ b/tests/integration_tests/__init__.py
@@ -0,0 +1,12 @@
+import random
+
+
+def random_mac_address() -> str:
+    """Generate a random MAC address.
+
+    The MAC address will have a 1 in its least significant bit, indicating it
+    to be a locally administered address.
+    """
+    return "02:00:00:%02x:%02x:%02x" % (random.randint(0, 255),
+                                        random.randint(0, 255),
+                                        random.randint(0, 255))