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