From b17a85bded822c4078a9b817720652807a939bc8 Mon Sep 17 00:00:00 2001
From: Christian Heimes <cheimes@redhat.com>
Date: Fri, 22 Jun 2018 09:39:26 +0200
Subject: [PATCH] Improve and fix timeout bug in wait_for_entry()

replication.wait_for_entry() now can wait for an attribute value to
appear on a replica.

Fixed timeout handling caused by bad rounding and comparison. For small
timeouts, the actual time was rounded down. For example for 60 seconds
timeout and fast replica, the query accumulated to about 0.45 seconds
plus 60 seconds sleep. 60.45 is large enough to terminate the loop
"while int(time.time()) < timeout", but not large enough to trigger the
exception in "if int(time.time()) > timeout", because int(60.65) == 60.

See: https://pagure.io/freeipa/issue/7593
Fixes: https://pagure.io/freeipa/issue/7595
Signed-off-by: Christian Heimes <cheimes@redhat.com>
Reviewed-By: Fraser Tweedale <ftweedal@redhat.com>
---
 ipaserver/install/replication.py | 54 +++++++++++++++++++++-------------------
 1 file changed, 29 insertions(+), 25 deletions(-)

diff --git a/ipaserver/install/replication.py b/ipaserver/install/replication.py
index 2e7ce53fef89093a7f661d846aa138ee330961e6..6d9878e16faab1b88a5ab79649571de6802c8536 100644
--- a/ipaserver/install/replication.py
+++ b/ipaserver/install/replication.py
@@ -20,6 +20,7 @@
 from __future__ import print_function, absolute_import
 
 import logging
+import itertools
 
 import six
 import time
@@ -160,40 +161,43 @@ def wait_for_task(conn, dn):
     return exit_code
 
 
-def wait_for_entry(connection, dn, timeout=7200, attr='', quiet=True):
-    """Wait for entry and/or attr to show up"""
-
-    filter = "(objectclass=*)"
+def wait_for_entry(connection, dn, timeout=7200, attr=None, attrvalue='*',
+                   quiet=True):
+    """Wait for entry and/or attr to show up
+    """
+    log = logger.debug if quiet else logger.info
     attrlist = []
-    if attr:
-        filter = "(%s=*)" % attr
+    if attr is not None:
+        filterstr = ipaldap.LDAPClient.make_filter_from_attr(attr, attrvalue)
         attrlist.append(attr)
-    timeout += int(time.time())
-
-    if not quiet:
-        sys.stdout.write("Waiting for %s %s:%s " % (connection, dn, attr))
-        sys.stdout.flush()
-    entry = None
-    while not entry and int(time.time()) < timeout:
+    else:
+        filterstr = "(objectclass=*)"
+    log("Waiting for replication (%s) %s %s", connection, dn, filterstr)
+    entry = []
+    deadline = time.time() + timeout
+    for i in itertools.count(start=1):
         try:
-            [entry] = connection.get_entries(
-                dn, ldap.SCOPE_BASE, filter, attrlist)
+            entry = connection.get_entries(
+                dn, ldap.SCOPE_BASE, filterstr, attrlist)
         except errors.NotFound:
             pass  # no entry yet
         except Exception as e:  # badness
             logger.error("Error reading entry %s: %s", dn, e)
             raise
-        if not entry:
-            if not quiet:
-                sys.stdout.write(".")
-                sys.stdout.flush()
-            time.sleep(1)
 
-    if not entry and int(time.time()) > timeout:
-        raise errors.NotFound(
-            reason="wait_for_entry timeout for %s for %s" % (connection, dn))
-    elif entry and not quiet:
-        logger.error("The waited for entry is: %s", entry)
+        if entry:
+            log("Entry found %r", entry)
+            return
+        elif time.time() > deadline:
+            raise errors.NotFound(
+                reason="wait_for_entry timeout on {} for {}".format(
+                    connection, dn
+                )
+            )
+        else:
+            if i % 10 == 0:
+                logger.debug("Still waiting for replication of %s", dn)
+            time.sleep(1)
 
 
 class ReplicationManager(object):
-- 
2.14.4