changes

server/DnsHandler.py

@@ -1,80 +1,73 @@
 import dns
+import dns.query
+import dns.update
+import dns.rdataclass
+import dns.rdatatype
+import dns.rdtypes.IN.A
+import dns.tsigkeyring 
+import threading
+from logger import Logger
+
 
 class DnsHandler(threading.Thread):
-    def __init__(self, msgQueue, tsigKey, nsAddress, ttl, nullIp):
+    def __init__(self, msgQueue, tsigKey, nsAddress, ttl, statusMap):
         threading.Thread.__init__(self)
         self.msgQueue = msgQueue
-        self.nullIp = nullIp
         self.nsAddress = nsAddress
         self.ttl = ttl
         self.keyring = dns.tsigkeyring.from_text(tsigKey)
+        self.statusMap = statusMap
+        self.setDaemon(True)
+
 
     def run(self):
         while(True):
             msg = self.msgQueue.get()
+
+            name = msg.name
+            zone = msg.zone
+            address = msg.address
             
-            if msg.successFlag:
-                # success
-                Logger.dbg("DnsManipulator: retrieved positive message")
-                if not self.statusMap.has_key(msg.ip) or not self.statusMap[msg.ip]:
-                    self.statusMap[msg.ip] = True
-                    self.insertARR(msg.ip)
-                    
-                    self.notifyQueue.put(NotificationMessage("Server returned", "Server %s is back" % msg.ip))
+            fullName = name + '.' + zone
+
+            if self.statusMap.has_key(fullName):
+                if self.statusMap[fullName] != address:
+                    self.deleteARR(name, zone, self.statusMap[fullName])
+                    self.insertARR(name, zone, address)
+                    self.statusMap[fullName] = address
             else:
-                # failure
-                Logger.dbg("DnsManipulator: retrieved negative message")
-                if not self.statusMap.has_key(msg.ip) or self.statusMap[msg.ip]:
-                    self.statusMap[msg.ip] = False
-                    self.deleteARR(msg.ip)
-
-                    self.notifyQueue.put(NotificationMessage("Server unavailable", "Server %s has gone" % msg.ip))
-
-            failureCnt = 0
-            for v in self.statusMap.values():
-                if not v:
-                    failureCnt += 1
-            
-            if failureCnt > 0 and not self.exitServerFlag:
-                self.insertARR(self.exitServerIp)
-                self.exitServerFlag = True
+                self.insertARR(name, zone, address)
+                self.statusMap[fullName] = address
                 
-            if failureCnt == 0 and self.exitServerFlag:
-                self.deleteARR(self.exitServerIp)
-                self.exitServerFlag = False
-
-                self.notifyQueue.put(NotificationMessage("All clear", "All clear, exit-server removed from DNS"))
                     
-    def insertARR(self, ip):
+    def insertARR(self, name, zone, address):
         # send A-RR insertion for ip to DNS server
-        Logger.log("insert ARR %s" % ip)
-
-        rr = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, ip)
-        u = dns.update.Update(self.zone, keyring=self.keyring)
-        u.add(self.name, self.ttl, rr)
+        rr = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, address)
+        u = dns.update.Update(zone, keyring=self.keyring)
+        u.add(name, self.ttl, rr)
         r = dns.query.tcp(u, self.nsAddress)
 
         if r.rcode() != 0:
             # failure
-            Logger.log("failure when inserting A-RR for %s" % ip)
+            Logger.log("failure when inserting A-RR %s -> %s into %s" % (name, address, zone))
         else:
             # success
-            pass
+            Logger.log("insert ARR %s -> %s into %s" % (name, address, zone))
 
-    def deleteARR(self, ip):
+
+    def deleteARR(self, name, zone, address):
         # send A-RR deletion for ip to DNS server
-        Logger.log("delete ARR %s" % ip)
-                
-        rr = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, ip)
-        u = dns.update.Update(self.zone, keyring=self.keyring)
-        u.delete(self.name, rr)
+        rr = dns.rdtypes.IN.A.A(dns.rdataclass.IN, dns.rdatatype.A, address)
+        u = dns.update.Update(zone, keyring=self.keyring)
+        u.delete(name, rr)
         r = dns.query.tcp(u, self.nsAddress)
 
         if r.rcode() != 0:
             # failure
-            Logger.log("failure when deleting A-RR for %s" % ip)
+            Logger.log("failure when deleting A-RR %s -> %s from %s" % (name, address, zone))
         else:
             # success
-            pass
+            Logger.log("delete ARR %s -> %s from %s" % (name, address, zone))
+