[bitbake-devel,RFC,v2,04/18] hashserv: tests: Add external database tests

diff --git a/lib/hashserv/tests.py b/lib/hashserv/tests.py
index 01ffd52c..4c98a280 100644
--- a/lib/hashserv/tests.py
+++ b/lib/hashserv/tests.py
@@ -51,13 +51,20 @@  class HashEquivalenceTestSetup(object):
         server.serve_as_process(prefunc=prefunc, args=(self.server_index,))
         self.addCleanup(cleanup_server, server)
 
+        return server
+
+    def start_client(self, server_address):
         def cleanup_client(client):
             client.close()
 
-        client = create_client(server.address)
+        client = create_client(server_address)
         self.addCleanup(cleanup_client, client)
 
-        return (client, server)
+        return client
+
+    def start_test_server(self):
+        server = self.start_server()
+        return server.address
 
     def setUp(self):
         if sys.version_info < (3, 5, 0):
@@ -66,7 +73,9 @@  class HashEquivalenceTestSetup(object):
         self.temp_dir = tempfile.TemporaryDirectory(prefix='bb-hashserv')
         self.addCleanup(self.temp_dir.cleanup)
 
-        (self.client, self.server) = self.start_server()
+        self.server_address = self.start_test_server()
+
+        self.client = self.start_client(self.server_address)
 
     def assertClientGetHash(self, client, taskhash, unihash):
         result = client.get_unihash(self.METHOD, taskhash)
@@ -206,7 +215,7 @@  class HashEquivalenceCommonTests(object):
 
     def test_stress(self):
         def query_server(failures):
-            client = Client(self.server.address)
+            client = Client(self.server_address)
             try:
                 for i in range(1000):
                     taskhash = hashlib.sha256()
@@ -245,8 +254,10 @@  class HashEquivalenceCommonTests(object):
         # the side client. It also verifies that the results are pulled into
         # the downstream database by checking that the downstream and side servers
         # match after the downstream is done waiting for all backfill tasks
-        (down_client, down_server) = self.start_server(upstream=self.server.address)
-        (side_client, side_server) = self.start_server(dbpath=down_server.dbpath)
+        down_server = self.start_server(upstream=self.server_address)
+        down_client = self.start_client(down_server.address)
+        side_server = self.start_server(dbpath=down_server.dbpath)
+        side_client = self.start_client(side_server.address)
 
         def check_hash(taskhash, unihash, old_sidehash):
             nonlocal down_client
@@ -351,14 +362,18 @@  class HashEquivalenceCommonTests(object):
         self.assertEqual(result['method'], self.METHOD)
 
     def test_ro_server(self):
-        (ro_client, ro_server) = self.start_server(dbpath=self.server.dbpath, read_only=True)
+        rw_server = self.start_server()
+        rw_client = self.start_client(rw_server.address)
+
+        ro_server = self.start_server(dbpath=rw_server.dbpath, read_only=True)
+        ro_client = self.start_client(ro_server.address)
 
         # Report a hash via the read-write server
         taskhash = '35788efcb8dfb0a02659d81cf2bfd695fb30faf9'
         outhash = '2765d4a5884be49b28601445c2760c5f21e7e5c0ee2b7e3fce98fd7e5970796f'
         unihash = 'f46d3fbb439bd9b921095da657a4de906510d2cd'
 
-        result = self.client.report_unihash(taskhash, self.METHOD, outhash, unihash)
+        result = rw_client.report_unihash(taskhash, self.METHOD, outhash, unihash)
         self.assertEqual(result['unihash'], unihash, 'Server returned bad unihash')
 
         # Check the hash via the read-only server
@@ -373,7 +388,7 @@  class HashEquivalenceCommonTests(object):
             ro_client.report_unihash(taskhash2, self.METHOD, outhash2, unihash2)
 
         # Ensure that the database was not modified
-        self.assertClientGetHash(self.client, taskhash2, None)
+        self.assertClientGetHash(rw_client, taskhash2, None)
 
 
     def test_slow_server_start(self):
@@ -393,7 +408,7 @@  class HashEquivalenceCommonTests(object):
         old_signal = signal.signal(signal.SIGTERM, do_nothing)
         self.addCleanup(signal.signal, signal.SIGTERM, old_signal)
 
-        _, server = self.start_server(prefunc=prefunc)
+        server = self.start_server(prefunc=prefunc)
         server.process.terminate()
         time.sleep(30)
         event.set()
@@ -500,3 +515,22 @@  class TestHashEquivalenceWebsocketServer(HashEquivalenceTestSetup, HashEquivalen
         # case it is more reliable to resolve the IP address explicitly.
         host = socket.gethostbyname("localhost")
         return "ws://%s:0" % host
+
+
+class TestHashEquivalenceExternalServer(HashEquivalenceTestSetup, HashEquivalenceCommonTests, unittest.TestCase):
+    def start_test_server(self):
+        if 'BB_TEST_HASHSERV' not in os.environ:
+            self.skipTest('BB_TEST_HASHSERV not defined to test an external server')
+
+        return os.environ['BB_TEST_HASHSERV']
+
+    def start_server(self, *args, **kwargs):
+        self.skipTest('Cannot start local server when testing external servers')
+
+    def setUp(self):
+        super().setUp()
+        self.client.remove({"method": self.METHOD})
+
+    def tearDown(self):
+        self.client.remove({"method": self.METHOD})
+        super().tearDown()