Use ReadFile/WriteFile in more places

This survived QA, burnin and unittests.
Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Luca Bigliardi <shammash@google.com>

lib/backend.py

@@ -51,6 +51,9 @@ from ganeti import objects
 from ganeti import ssconf
 
 
+_BOOT_ID_PATH = "/proc/sys/kernel/random/boot_id"
+
+
 class RPCFail(Exception):
   """Class denoting RPC failure.
 
@@ -58,6 +61,7 @@ class RPCFail(Exception):
 
   """
 
+
 def _Fail(msg, *args, **kwargs):
   """Log an error and the raise an RPCFail exception.
 
@@ -364,11 +368,7 @@ def LeaveCluster():
   try:
     priv_key, pub_key, auth_keys = ssh.GetUserFiles(constants.GANETI_RUNAS)
 
-    f = open(pub_key, 'r')
-    try:
-      utils.RemoveAuthorizedKey(auth_keys, f.read(8192))
-    finally:
-      f.close()
+    utils.RemoveAuthorizedKey(auth_keys, utils.ReadFile(pub_key))
 
     utils.RemoveFile(priv_key)
     utils.RemoveFile(pub_key)
@@ -406,11 +406,7 @@ def GetNodeInfo(vgname, hypervisor_type):
   if hyp_info is not None:
     outputarray.update(hyp_info)
 
-  f = open("/proc/sys/kernel/random/boot_id", 'r')
-  try:
-    outputarray["bootid"] = f.read(128).rstrip("\n")
-  finally:
-    f.close()
+  outputarray["bootid"] = utils.ReadFile(_BOOT_ID_PATH, size=128).rstrip("\n")
 
   return outputarray
 

lib/bdev.py

@@ -780,11 +780,7 @@ class BaseDRBD(BlockDev):
 
     """
     try:
-      stat = open(filename, "r")
-      try:
-        data = stat.read().splitlines()
-      finally:
-        stat.close()
+      data = utils.ReadFile(filename).splitlines()
     except EnvironmentError, err:
       if err.errno == errno.ENOENT:
         _ThrowError("The file %s cannot be opened, check if the module"

lib/bootstrap.py

@@ -63,11 +63,7 @@ def _InitSSHSetup():
     raise errors.OpExecError("Could not generate ssh keypair, error %s" %
                              result.output)
 
-  f = open(pub_key, 'r')
-  try:
-    utils.AddAuthorizedKey(auth_keys, f.read(8192))
-  finally:
-    f.close()
+  utils.AddAuthorizedKey(auth_keys, utils.ReadFile(auth_keys))
 
 
 def _GenerateSelfSignedSslCert(file_name, validity=(365 * 5)):
@@ -240,11 +236,7 @@ def InitCluster(cluster_name, mac_prefix,
   _InitGanetiServerSetup()
 
   # set up ssh config and /etc/hosts
-  f = open(constants.SSH_HOST_RSA_PUB, 'r')
-  try:
-    sshline = f.read()
-  finally:
-    f.close()
+  sshline = utils.ReadFile(constants.SSH_HOST_RSA_PUB)
   sshkey = sshline.split(" ")[1]
 
   if modify_etc_hosts:

lib/cmdlib.py

@@ -2799,11 +2799,7 @@ class LUAddNode(LogicalUnit):
                 priv_key, pub_key]
 
     for i in keyfiles:
-      f = open(i, 'r')
-      try:
-        keyarray.append(f.read())
-      finally:
-        f.close()
+      keyarray.append(utils.ReadFile(i))
 
     result = self.rpc.call_node_add(node, keyarray[0], keyarray[1],
                                     keyarray[2],

lib/config.py

@@ -1041,14 +1041,12 @@ class ConfigWriter:
     """Read the config data from disk.
 
     """
-    f = open(self._cfg_file, 'r')
+    raw_data = utils.ReadFile(self._cfg_file)
+
     try:
-      try:
-        data = objects.ConfigData.FromDict(serializer.Load(f.read()))
-      except Exception, err:
-        raise errors.ConfigurationError(err)
-    finally:
-      f.close()
+      data = objects.ConfigData.FromDict(serializer.Load(raw_data))
+    except Exception, err:
+      raise errors.ConfigurationError(err)
 
     # Make sure the configuration has the right version
     _ValidateConfig(data)
@@ -1113,16 +1111,9 @@ class ConfigWriter:
       destination = self._cfg_file
     self._BumpSerialNo()
     txt = serializer.Dump(self._config_data.ToDict())
-    dir_name, file_name = os.path.split(destination)
-    fd, name = tempfile.mkstemp('.newconfig', file_name, dir_name)
-    f = os.fdopen(fd, 'w')
-    try:
-      f.write(txt)
-      os.fsync(f.fileno())
-    finally:
-      f.close()
-    # we don't need to do os.close(fd) as f.close() did it
-    os.rename(name, destination)
+
+    utils.WriteFile(destination, data=txt)
+
     self.write_count += 1
 
     # and redistribute the config file to master candidates

lib/jqueue.py

@@ -661,11 +661,7 @@ class JobQueue(object):
 
     for file_name in files:
       # Read file content
-      fd = open(file_name, "r")
-      try:
-        content = fd.read()
-      finally:
-        fd.close()
+      content = utils.ReadFile(file_name)
 
       result = rpc.RpcRunner.call_jobqueue_update([node_name],
                                                   [node.primary_ip],
@@ -917,15 +913,13 @@ class JobQueue(object):
     filepath = self._GetJobPath(job_id)
     logging.debug("Loading job from %s", filepath)
     try:
-      fd = open(filepath, "r")
+      raw_data = utils.ReadFile(filepath)
     except IOError, err:
       if err.errno in (errno.ENOENT, ):
         return None
       raise
-    try:
-      data = serializer.LoadJson(fd.read())
-    finally:
-      fd.close()
+
+    data = serializer.LoadJson(raw_data)
 
     try:
       job = _QueuedJob.Restore(self, data)

lib/utils.py

@@ -63,6 +63,8 @@ debug_locks = False
 #: when set to True, L{RunCmd} is disabled
 no_fork = False
 
+_RANDOM_UUID_FILE = "/proc/sys/kernel/random/uuid"
+
 
 class RunResult(object):
   """Holds the result of running external programs.
@@ -472,14 +474,14 @@ def ReadPidFile(pidfile):
 
   """
   try:
-    pf = open(pidfile, 'r')
+    raw_data = ReadFile(pidfile)
   except EnvironmentError, err:
     if err.errno != errno.ENOENT:
-      logging.exception("Can't read pid file?!")
+      logging.exception("Can't read pid file")
     return 0
 
   try:
-    pid = int(pf.read())
+    pid = int(raw_data)
   except ValueError, err:
     logging.info("Can't parse pid file contents", exc_info=True)
     return 0
@@ -1150,11 +1152,7 @@ def NewUUID():
   @rtype: str
 
   """
-  f = open("/proc/sys/kernel/random/uuid", "r")
-  try:
-    return f.read(128).rstrip("\n")
-  finally:
-    f.close()
+  return ReadFile(_RANDOM_UUID_FILE, size=128).rstrip("\n")
 
 
 def GenerateSecret(numbytes=20):

scripts/gnt-debug

@@ -72,7 +72,7 @@ def GenericOpCodes(opts, args):
   jex = cli.JobExecutor(cl=cl)
 
   for fname in args:
-    op_data = simplejson.loads(open(fname).read())
+    op_data = simplejson.loads(utils.ReadFile(fname))
     op_list = [opcodes.OpCode.LoadOpCode(val) for val in op_data]
     jex.QueueJob("file %s" % fname, *op_list)
 

scripts/gnt-instance

@@ -443,9 +443,7 @@ def BatchCreate(opts, args):
 
   json_filename = args[0]
   try:
-    fd = open(json_filename, 'r')
-    instance_data = simplejson.load(fd)
-    fd.close()
+    instance_data = simplejson.loads(utils.ReadFile(json_filename))
   except Exception, err:
     ToStderr("Can't parse the instance definition file: %s" % str(err))
     return 1