diff --git a/server-ca/daemon_common.py b/server-ca/daemon_common.py
index 42c1f8e1d..80a0cb146 100644
--- a/server-ca/daemon_common.py
+++ b/server-ca/daemon_common.py
@@ -2,9 +2,6 @@
 
 # functions common to the various kinds of daemon
 
-# TODO: define a log function that sends a pubsub message to the
-# logger daemon
-
 import time, binascii
 from Crypto import Random
 
@@ -27,3 +24,9 @@ def random():
 def random_raw():
     """Return 32 random bytes."""
     return Random.get_random_bytes(32)
+
+def log(msg, session = None):
+    if session:
+        r.publish("logs", "%s: %s" % (short(session), msg))
+    else:
+        r.publish("logs", "%s" % session)