Packages: Added timeout to bcfg2-yum-helper calls

This involved making the Yum backend use Bcfg2.Utils.Executor to call
bcfg2-yum-helper instead of subprocess.Popen directly.  This was
cherry-picked (kinda) from 3d06f311274d6b942ee89d8cdb13b2ecc99af1b0,
so will likely break the maint -> master merge in spectacular ways.

2 files changed, 22 insertions, 35 deletions

diff --git a/src/lib/Bcfg2/Options.py b/src/lib/Bcfg2/Options.py
index dba3e96ef..3d105bf30 100644
--- a/src/lib/Bcfg2/Options.py
+++ b/src/lib/Bcfg2/Options.py
@@ -1221,7 +1221,8 @@ SERVER_COMMON_OPTIONS = dict(repo=SERVER_REPOSITORY,
                              authentication=SERVER_AUTHENTICATION,
                              perflog=LOG_PERFORMANCE,
                              perflog_interval=PERFLOG_INTERVAL,
-                             children=SERVER_CHILDREN)
+                             children=SERVER_CHILDREN,
+                             client_timeout=CLIENT_TIMEOUT)
 
 CRYPT_OPTIONS = dict(encrypt=ENCRYPT,
                      decrypt=DECRYPT,
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py b/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
index 7a90f4f2e..e0002ef34 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
@@ -59,9 +59,9 @@ import errno
 import socket
 import logging
 import lxml.etree
-from lockfile import FileLock
-from subprocess import Popen, PIPE
 import Bcfg2.Server.Plugin
+from lockfile import FileLock
+from Bcfg2.Utils import Executor
 # pylint: disable=W0622
 from Bcfg2.Compat import StringIO, cPickle, HTTPError, URLError, \
     ConfigParser, any
@@ -279,6 +279,7 @@ class YumCollection(Collection):
                             debug=debug)
         self.keypath = os.path.join(self.cachepath, "keys")
 
+        self._helper = None
         if self.use_yum:
             #: Define a unique cache file for this collection to use
             #: for cached yum metadata
@@ -294,8 +295,10 @@ class YumCollection(Collection):
                 os.mkdir(self.cachefile)
                 if not self.disableMetaData:
                     self.setup_data()
+            self.cmd = Executor()
         else:
             self.cachefile = None
+            self.cmd = None
 
         if HAS_PULP and self.has_pulp_sources:
             _setup_pulp(self.setup)
@@ -348,20 +351,18 @@ class YumCollection(Collection):
         a call to it; I wish there was a way to do this without
         forking, but apparently not); finally we check in /usr/sbin,
         the default location. """
-        global HELPER
-        if not HELPER:
+        if not self._helper:
             try:
-                HELPER = self.setup.cfp.get("packages:yum", "helper")
+                self._helper = self.setup.cfp.get("packages:yum", "helper")
             except (ConfigParser.NoOptionError, ConfigParser.NoSectionError):
                 # first see if bcfg2-yum-helper is in PATH
                 try:
                     self.debug_log("Checking for bcfg2-yum-helper in $PATH")
-                    Popen(['bcfg2-yum-helper'],
-                          stdin=PIPE, stdout=PIPE, stderr=PIPE).wait()
-                    HELPER = 'bcfg2-yum-helper'
+                    self.cmd.run(['bcfg2-yum-helper'])
+                    self._helper = 'bcfg2-yum-helper'
                 except OSError:
-                    HELPER = "/usr/sbin/bcfg2-yum-helper"
-        return HELPER
+                    self._helper = "/usr/sbin/bcfg2-yum-helper"
+        return self._helper
 
     @property
     def use_yum(self):
@@ -925,36 +926,21 @@ class YumCollection(Collection):
             cmd.append("-v")
         cmd.append(command)
         self.debug_log("Packages: running %s" % " ".join(cmd))
-        try:
-            helper = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=PIPE)
-        except OSError:
-            err = sys.exc_info()[1]
-            self.logger.error("Packages: Failed to execute %s: %s" %
-                              (" ".join(cmd), err))
-            return None
 
         if inputdata:
-            idata = json.dumps(inputdata)
-            (stdout, stderr) = helper.communicate(idata)
+            result = self.cmd.run(cmd, timeout=self.setup['client_timeout'],
+                                  inputdata=json.dumps(inputdata))
         else:
-            (stdout, stderr) = helper.communicate()
-        rv = helper.wait()
-        errlines = stderr.splitlines()
-        if rv:
-            if not errlines:
-                errlines.append("No error output")
-            self.logger.error("Packages: error running bcfg2-yum-helper "
-                              "(returned %d): %s" % (rv, errlines[0]))
-            for line in errlines[1:]:
-                self.logger.error("Packages: %s" % line)
-        elif errlines:
+            result = self.cmd.run(cmd, timeout=self.setup['client_timeout'])
+        if not result.success:
+            self.logger.error("Packages: error running bcfg2-yum-helper: %s" %
+                              result.error)
+        elif result.stderr:
             self.debug_log("Packages: debug info from bcfg2-yum-helper: %s" %
-                           errlines[0])
-            for line in errlines[1:]:
-                self.debug_log("Packages: %s" % line)
+                           result.stderr)
 
         try:
-            return json.loads(stdout)
+            return json.loads(result.stdout)
         except ValueError:
             err = sys.exc_info()[1]
             self.logger.error("Packages: error reading bcfg2-yum-helper "