Add __eq__ and __hash__ method for MarathonBackend to fix issue #675

marathon_lb.py

@@ -91,6 +91,35 @@ def __hash__(self):
     def __repr__(self):
         return "MarathonBackend(%r, %r, %r)" % (self.host, self.ip, self.port)
 
+    def __hash__(self):
+        "Return the hash value of a friendly backend server name"
+        return hash(self.friendly_server_name())
+
+    def __eq__(self, oth):
+        """
+        Return true if both backend server name are same, else false.
+        The friendly server name uses to calculate haproxy server id.
+        """
+        return isinstance(oth, MarathonBackend) and \
+            self.friendly_server_name() == oth.friendly_server_name()
+
+    def friendly_server_name(self):
+        """
+        Return a unique, friendly name for the backend server.
+
+        Concat the host, task IP and task port together. If the host and task
+        IP are actually the same then omit one for clarity.
+        """
+
+        if self.host != self.ip:
+            serverHost = self.host + '_' + self.ip
+        else:
+            serverHost = self.ip
+
+        serverHostName = re.sub(r'[^a-zA-Z0-9\-]', '_', serverHost)
+
+        return serverHostName + '_' + str(self.port)
+
 
 class MarathonService(object):
 
@@ -692,20 +721,7 @@ def config(apps, groups, bind_http_https, ssl_certs, templater,
                 backendServer.port,
                 backendServer.host)
 
-            # Create a unique, friendly name for the backend server.  We concat
-            # the host, task IP and task port together.  If the host and task
-            # IP are actually the same then omit one for clarity.
-            if backendServer.host != backendServer.ip:
-                serverName = re.sub(
-                    r'[^a-zA-Z0-9\-]', '_',
-                    (backendServer.host + '_' +
-                     backendServer.ip + '_' +
-                     str(backendServer.port)))
-            else:
-                serverName = re.sub(
-                    r'[^a-zA-Z0-9\-]', '_',
-                    (backendServer.ip + '_' +
-                     str(backendServer.port)))
+            serverName = backendServer.friendly_server_name()
             shortHashedServerName = hashlib.sha1(serverName.encode()) \
                 .hexdigest()[:10]
 
@@ -1451,8 +1467,8 @@ def generateAndValidateTempConfig(config, config_file, domain_map_array,
         app_map_string = generateMapString(app_map_array)
 
     return writeConfigAndValidate(
-                config, temp_config_file, domain_map_string, domain_map_file,
-                app_map_string, app_map_file, haproxy_map)
+        config, temp_config_file, domain_map_string, domain_map_file,
+        app_map_string, app_map_file, haproxy_map)
 
 
 def compareWriteAndReloadConfig(config, config_file, domain_map_array,