From 3cb608649685821457252e34b350216123ffa89f Mon Sep 17 00:00:00 2001
From: Erik Reid <erik.reid@geant.org>
Date: Thu, 7 Feb 2019 21:21:11 +0100
Subject: [PATCH] fix race condition
iterating over keys & then non-atomically fetching value ...
---
inventory_provider/tasks/worker.py | 48 ++++++++++++++++--------------
1 file changed, 25 insertions(+), 23 deletions(-)
diff --git a/inventory_provider/tasks/worker.py b/inventory_provider/tasks/worker.py
index a8ecc42a..cdfc648f 100644
--- a/inventory_provider/tasks/worker.py
+++ b/inventory_provider/tasks/worker.py
@@ -238,38 +238,40 @@ def clear_cached_classifier_responses(hostname):
r.delete(k)
-def refresh_ix_public_peers(hostname, netconf):
+def _refresh_peers(hostname, key_base, peers):
task_logger = logging.getLogger(constants.TASK_LOGGER_NAME)
task_logger.debug(
- 'removing cached ix public peers for %r' % hostname)
+ 'removing cached %s for %r' % (key_base, hostname))
r = get_redis(InventoryTask.config)
- for k in r.keys('ix_public_peer:*'):
- value = json.loads(r.get(k.decode('utf-8')).decode('utf-8'))
- if value['router'] == hostname:
- r.delete(k)
-
- for peer in juniper.ix_public_peers(netconf):
+ for k in r.keys(key_base + ':*'):
+ # potential race condition: another proc could have
+ # delete this element between the time we read the
+ # keys and the next statement ... check for None below
+ value = r.get(k.decode('utf-8'))
+ if value:
+ value = json.loads(value.decode('utf-8'))
+ if value['router'] == hostname:
+ r.delete(k)
+
+ for peer in peers:
peer['router'] = hostname
r.set(
- 'ix_public_peer:' + peer['name'],
+ '%s:%s' % (key_base, peer['name']),
json.dumps(peer))
-def refresh_vpn_rr_peers(hostname, netconf):
- task_logger = logging.getLogger(constants.TASK_LOGGER_NAME)
- task_logger.debug(
- 'removing cached vpn rr for %r' % hostname)
- r = get_redis(InventoryTask.config)
- for k in r.keys('vpn_rr_peer:*'):
- value = json.loads(r.get(k.decode('utf-8')).decode('utf-8'))
- if value['router'] == hostname:
- r.delete(k)
+def refresh_ix_public_peers(hostname, netconf):
+ _refresh_peers(
+ hostname,
+ 'ix_public_peer',
+ juniper.ix_public_peers(netconf))
- for peer in juniper.vpn_rr_peers(netconf):
- peer['router'] = hostname
- r.set(
- 'vpn_rr_peer:' + peer['name'],
- json.dumps(peer))
+
+def refresh_vpn_rr_peers(hostname, netconf):
+ _refresh_peers(
+ hostname,
+ 'vpn_rr_peer',
+ juniper.vpn_rr_peers(netconf))
@app.task
--
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