Skip octavia tests with compute when using fixed networks

Tests with compute require dynamic networks at the moment, skip
unless fixed network support is implemented

Related-Prod: PRODX-20952
Change-Id: I521787aeb8c5736a1a5b0278dfdde10d2f06d3a1
diff --git a/octavia_tempest_plugin/tests/test_base.py b/octavia_tempest_plugin/tests/test_base.py
index b491c5c..8082450 100644
--- a/octavia_tempest_plugin/tests/test_base.py
+++ b/octavia_tempest_plugin/tests/test_base.py
@@ -543,6 +543,17 @@
 
 
 class LoadBalancerBaseTestWithCompute(LoadBalancerBaseTest):
+
+    @classmethod
+    def skip_checks(cls):
+        """Check if we should skip all of the children tests."""
+        super(LoadBalancerBaseTest, cls).skip_checks()
+
+        # TODO(vsaienko): Implement tests for fixed network.
+        if not CONF.auth.create_isolated_networks:
+            msg = ('Skip tests as they require dynamic networks.')
+            raise cls.skipException(msg)
+
     @classmethod
     def resource_setup(cls):
         super(LoadBalancerBaseTestWithCompute, cls).resource_setup()