Allow to override cache and dir via env.

slapos/libnetworkcachetests.py

@@ -20,8 +20,8 @@ class OfflineTest(unittest.TestCase):
 class OnlineTest(unittest.TestCase):
   """Online tests against real (or simulated?) HTTP server"""
   def setUp(self):
-    self.shacache = 'http://127.0.0.1:8080'
-    self.shadir = 'http://127.0.0.1:8080'
+    self.shacache = os.environ.get('TEST_SHA_CACHE', 'http://127.0.0.1:8080')
+    self.shadir = os.environ.get('TEST_SHA_DIR', 'http://127.0.0.1:8080')
     self.test_data = tempfile.TemporaryFile()
     self.test_string = str(random.random())
     self.test_data.write(self.test_string)