dnstools: make timeouts configurable via ENV, travis: use longer timeouts

.travis.yml

@@ -6,6 +6,8 @@ python:
 env:
     global:
       - SECRET_KEY=justfortravis
+      - DNS_RESOLVER_TIMEOUT=15.0
+      - DNS_UPDATE_TIMEOUT=30.0
     matrix:
       - DJANGO=1.5.5
       - DJANGO=1.6.1

nsupdate/main/dnstools.py

@@ -4,11 +4,13 @@ Misc. DNS related code: query, dynamic update, etc.
 Usually, higher level code wants to call the add/update/delete functions.
 """
 
+import os
+
 # time to wait for dns name resolving [s]
-RESOLVER_TIMEOUT = 5.0
+RESOLVER_TIMEOUT = float(os.environ.get('DNS_RESOLVER_TIMEOUT', '5.0'))
 
 # time to wait for dns name updating [s]
-UPDATE_TIMEOUT = 20.0
+UPDATE_TIMEOUT = float(os.environ.get('DNS_UPDATE_TIMEOUT', '20.0'))
 
 # time after we retry to reach a previously unreachable ns [s]
 UNAVAILABLE_RETRY = 300.0