Merge lp:~hopem/charms/trusty/glance/charm-helpers-sync-1396246 into lp:~openstack-charmers-archive/charms/trusty/glance/next

[Edward Hope-Morley]

[uosci-testing-bot (uosci-testing-bot)]

charm_lint_check #275 glance-next for hopem mp245092
    LINT OK: passed

Build: http://10.245.162.77:8080/job/charm_lint_check/275/

[uosci-testing-bot (uosci-testing-bot)]

charm_unit_test #303 glance-next for hopem mp245092
    UNIT OK: passed

Build: http://10.245.162.77:8080/job/charm_unit_test/303/

[uosci-testing-bot (uosci-testing-bot)]

charm_amulet_test #438 glance-next for hopem mp245092
    AMULET OK: passed

Build: http://10.245.162.77:8080/job/charm_amulet_test/438/

[Corey Bryant (corey.bryant)]

review: Approve

=== modified file 'hooks/charmhelpers/contrib/hahelpers/cluster.py'
--- hooks/charmhelpers/contrib/hahelpers/cluster.py	2014-12-10 20:28:49 +0000
+++ hooks/charmhelpers/contrib/hahelpers/cluster.py	2014-12-18 11:34:06 +0000
@@ -13,6 +13,7 @@
 
 import subprocess
 import os
+
 from socket import gethostname as get_unit_hostname
 
 import six
@@ -28,12 +29,19 @@
     WARNING,
     unit_get,
 )
+from charmhelpers.core.decorators import (
+    retry_on_exception,
+)
 
 
 class HAIncompleteConfig(Exception):
     pass
 
 
+class CRMResourceNotFound(Exception):
+    pass
+
+
 def is_elected_leader(resource):
     """
     Returns True if the charm executing this is the elected cluster leader.
@@ -68,24 +76,30 @@
     return False
 
 
-def is_crm_leader(resource):
+@retry_on_exception(5, base_delay=2, exc_type=CRMResourceNotFound)
+def is_crm_leader(resource, retry=False):
     """
     Returns True if the charm calling this is the elected corosync leader,
     as returned by calling the external "crm" command.
+
+    We allow this operation to be retried to avoid the possibility of getting a
+    false negative. See LP #1396246 for more info.
     """
-    cmd = [
-        "crm", "resource",
-        "show", resource
-    ]
+    cmd = ['crm', 'resource', 'show', resource]
     try:
-        status = subprocess.check_output(cmd).decode('UTF-8')
+        status = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
+        if not isinstance(status, six.text_type):
+            status = six.text_type(status, "utf-8")
     except subprocess.CalledProcessError:
-        return False
-    else:
-        if get_unit_hostname() in status:
-            return True
-        else:
-            return False
+        status = None
+
+    if status and get_unit_hostname() in status:
+        return True
+
+    if status and "resource %s is NOT running" % (resource) in status:
+        raise CRMResourceNotFound("CRM resource %s not found" % (resource))
+
+    return False
 
 
 def is_leader(resource):
 
=== added file 'hooks/charmhelpers/core/decorators.py'
--- hooks/charmhelpers/core/decorators.py	1970-01-01 00:00:00 +0000
+++ hooks/charmhelpers/core/decorators.py	2014-12-18 11:34:06 +0000
@@ -0,0 +1,41 @@
+#
+# Copyright 2014 Canonical Ltd.
+#
+# Authors:
+#  Edward Hope-Morley <[e-mail]>
+#
+
+import time
+
+from charmhelpers.core.hookenv import (
+    log,
+    INFO,
+)
+
+
+def retry_on_exception(num_retries, base_delay=0, exc_type=Exception):
+    """If the decorated function raises exception exc_type, allow num_retries
+    retry attempts before raise the exception.
+    """
+    def _retry_on_exception_inner_1(f):
+        def _retry_on_exception_inner_2(*args, **kwargs):
+            retries = num_retries
+            multiplier = 1
+            while True:
+                try:
+                    return f(*args, **kwargs)
+                except exc_type:
+                    if not retries:
+                        raise
+
+                delay = base_delay * multiplier
+                multiplier += 1
+                log("Retrying '%s' %d more times (delay=%s)" %
+                    (f.__name__, retries, delay), level=INFO)
+                retries -= 1
+                if delay:
+                    time.sleep(delay)
+
+        return _retry_on_exception_inner_2
+
+    return _retry_on_exception_inner_1
 
=== modified file 'hooks/charmhelpers/core/host.py'
--- hooks/charmhelpers/core/host.py	2014-12-15 10:16:05 +0000
+++ hooks/charmhelpers/core/host.py	2014-12-18 11:34:06 +0000
@@ -162,13 +162,16 @@
     uid = pwd.getpwnam(owner).pw_uid
     gid = grp.getgrnam(group).gr_gid
     realpath = os.path.abspath(path)
-    if os.path.exists(realpath):
-        if force and not os.path.isdir(realpath):
+    path_exists = os.path.exists(realpath)
+    if path_exists and force:
+        if not os.path.isdir(realpath):
             log("Removing non-directory file {} prior to mkdir()".format(path))
             os.unlink(realpath)
-    else:
+            os.makedirs(realpath, perms)
+        os.chown(realpath, uid, gid)
+    elif not path_exists:
         os.makedirs(realpath, perms)
-    os.chown(realpath, uid, gid)
+        os.chown(realpath, uid, gid)
 
 
 def write_file(path, content, owner='root', group='root', perms=0o444):