Prevent duplicate 'fingerprint changed' notices

Strange. It doesn't commonly happen but as reported in... https://trac.torproject.org/projects/tor/ticket/25789 ... sometimes we list a relay twice. My only guess is that this arises if a particular address/port is a relay in the consensus twice. Adjusting the code in a way that should deduplicate these.

Prevent duplicate 'fingerprint changed' notices
0e5010b0 · Damian Johnson · 82435ed8 · 0e5010b0
Commit 0e5010b0 authored Apr 14, 2018 by Damian Johnson
--- a/fingerprint_change_checker.py
+++ b/fingerprint_change_checker.py
@@ -42,7 +42,7 @@ def main():

  fingerprint_changes = load_fingerprint_changes()
  downloader = DescriptorDownloader(timeout = 15)
-  alarm_for = set()
+  alarm_for = {}

  for relay in downloader.get_consensus():
    prior_fingerprints = fingerprint_changes.setdefault((relay.address, relay.or_port), {})
@@ -62,13 +62,13 @@ def main():
      # if we've changed more than ten times in the last ten days then alarm

      if len(prior_fingerprints) >= 10:
-        alarm_for.add((relay.address, relay.or_port, relay.fingerprint))
+        alarm_for['%s:%s' % (relay.address, relay.or_port)] = (relay.address, relay.or_port, relay.fingerprint)

-  if alarm_for and not is_notification_suppressed(alarm_for):
+  if alarm_for and not is_notification_suppressed(alarm_for.values()):
    log.debug("Sending a notification for %i relays..." % len(alarm_for))
    body = EMAIL_BODY

-    for address, or_port, fingerprint in alarm_for:
+    for address, or_port, fingerprint in alarm_for.values():
      try:
        desc = downloader.get_server_descriptors(fingerprint).run()[0]
      except:
@@ -102,7 +102,7 @@ def main():
    subject = EMAIL_SUBJECT

    if len(alarm_for) == 1:
-      subject += ' (%s:%s)' % list(alarm_for)[0][:2]
+      subject += ' (%s:%s)' % alarm_for.values()[0][:2]

    util.send(subject, body = body, to = ['bad-relays@lists.torproject.org', 'atagar@torproject.org'])

@@ -110,7 +110,7 @@ def main():

    current_time = str(int(time.time()))

-    for address, or_port, _ in alarm_for:
+    for address, or_port, _ in alarm_for.values():
      last_notified_config.set('%s:%s' % (address, or_port), current_time)

    last_notified_config.save()