Add helper class for core network handling in CI

This adds a helper class to manage various core networks in the CI
testing framework. Specifically, it reads from a YAML file information
such as a node, (un-)deployment script (file), log collection
instructions, etc., in order to allow a common interface to be used to
deploy and undeploy various core network implementations.

This commit adds the class (in cls_corenetwork.py) as well as tests for
this class.

ci-scripts/tests/corenetwork.py

@@ -0,0 +1,66 @@
+import sys
+import logging
+logging.basicConfig(
+	level=logging.DEBUG,
+	stream=sys.stdout,
+	format="[%(asctime)s] %(levelname)8s: %(message)s"
+)
+import os
+
+import unittest
+
+sys.path.append('./') # to find OAI imports below
+import cls_corenetwork
+import cls_cmd
+
+class TestCoreNetwork(unittest.TestCase):
+    def test_simple_core(self):
+        c = cls_corenetwork.CoreNetwork("test", filename="tests/config/test_core_infra.yaml")
+        success, output = c.deploy()
+        self.assertTrue(success)
+        self.assertEqual(output, "deploy")
+        # should not have it set in config
+        self.assertTrue(c.runIperf3Server())
+        self.assertEqual(c.getIP(), "127.0.0.1")
+        log_files, output = c.undeploy(log_dir="/tmp")
+        self.assertEqual(output, "undeploy")
+        with cls_cmd.LocalCmd() as cmd:
+            # there must be one log file for this (test) core
+            self.assertEqual(len(log_files), 1)
+            # test core writes to %%log_dir%%/logs, which expands to /tmp/logs
+            l = log_files[0]
+            self.assertEqual(l, "/tmp/logs")
+            ret = cmd.run(f"cat {l}")
+            self.assertEqual(ret.returncode, 0) # command must succeed
+            self.assertEqual(ret.stdout, "logs") # output should be "logs"
+
+    def test_core_list(self):
+        c = cls_corenetwork.CoreNetwork("test_list", filename="tests/config/test_core_infra.yaml")
+        success, _ = c.deploy()
+        self.assertTrue(success)
+        self.assertFalse(c.runIperf3Server())
+        c.undeploy(log_dir="/tmp")
+
+    def test_core_fail(self):
+        c = cls_corenetwork.CoreNetwork("test_fail", filename="tests/config/test_core_infra.yaml")
+        success, _ = c.deploy()
+        self.assertFalse(success)
+        # undeployment should still work
+        c.undeploy(log_dir="/tmp")
+
+    def test_core_script(self):
+        c = cls_corenetwork.CoreNetwork("test_script", filename="tests/config/test_core_infra.yaml")
+        success, output = c.deploy()
+        self.assertTrue(success)
+        self.assertEqual(output, "deployment from script")
+        c.undeploy()
+
+    def test_core_script_fail(self):
+        c = cls_corenetwork.CoreNetwork("test_script_fail", filename="tests/config/test_core_infra.yaml")
+        success, output = c.deploy()
+        self.assertFalse(success)
+        self.assertEqual(output, "deployment from script\nfailing")
+        c.undeploy()
+
+if __name__ == '__main__':
+    unittest.main()