handled exception if the docker deamon does not expose events on the REST-API

nginx_proxy.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python3.4
 
 import os
+import sys
 import http.client
 import json
 import signal
@@ -118,7 +119,12 @@ if not os.path.exists(target_path):
 pid = get_pid()
 
 conn = http.client.HTTPConnection("localhost:2375")
-conn.request("GET", "/events")
+try:
+	conn.request("GET", "/events")
+except ConnectionRefusedError:
+	print('Docker does not expose events on its REST-API. Perhaps it is not running?')
+	sys.exit(-1)
+
 response = conn.getresponse()
 
 events = ""