IMPALA-9157: Make helper function exec_local_command python 2.6 compatible

Change-Id: I928a4df9dc883e8e801a42ead14ec7875169d4ae
Reviewed-on: http://gerrit.cloudera.org:8080/14788
Reviewed-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>
Tested-by: Impala Public Jenkins <impala-public-jenkins@cloudera.com>

lib/python/impala_py_lib/helpers.py

@@ -16,22 +16,35 @@
 # under the License.
 
 import fnmatch
+import logging
 import os
 import re
 import subprocess
 
+logging.basicConfig()
+LOG = logging.getLogger('impala_lib_python_helpers')
+
 
 def exec_local_command(cmd):
   """
   Executes a command for the local bash shell and return stdout as a string.
 
+  Raise CalledProcessError in case of  non-zero return code.
+
   Args:
     cmd: command as a string
 
   Return:
     STDOUT
   """
-  return subprocess.check_output(cmd.split())
+  proc = subprocess.Popen(cmd.split(), stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+  output, error = proc.communicate()
+  retcode = proc.poll()
+  if retcode:
+    LOG.error("{0} returned status {1}: {2}".format(cmd, retcode, error))
+    raise subprocess.CalledProcessError()
+  else:
+    return output
 
 
 def find_all_files(fname_pattern, base_dir=os.getenv('IMPALA_HOME', '.')):