file handling cleanup

slapos/grid/slapgrid.py

@@ -582,9 +582,8 @@ class Slapgrid(object):
             except NotFoundError:
               pass
             software.install()
-            file_descriptor = open(completed_tag, 'w')
-            file_descriptor.write(time.asctime())
-            file_descriptor.close()
+            with open(completed_tag, 'w') as fout:
+              fout.write(time.asctime())
         elif state == 'destroyed':
           if os.path.exists(software_path):
             logger.info('Destroying %r...' % software_release_uri)
@@ -665,7 +664,6 @@ class Slapgrid(object):
         promise = os.path.basename(command[0])
         self.logger.info("Checking promise %r.", promise)
 
-
         process_handler = subprocess.Popen(command,
                                            preexec_fn=lambda: dropPrivileges(uid, gid),
                                            cwd=cwd,
@@ -1169,9 +1167,7 @@ class Slapgrid(object):
 
           file_path = os.path.join(dir_reports, filename)
           if os.path.exists(file_path):
-            usage_file = open(file_path, 'r')
-            usage = usage_file.read()
-            usage_file.close()
+            usage = open(file_path, 'r').read()
 
             #We check the validity of xml content of each reports
             if not self.validateXML(usage, partition_consumption_model):

slapos/grid/utils.py

@@ -111,9 +111,7 @@ class SlapPopen(subprocess.Popen):
       if line == '' and self.poll() != None:
         break
       output_lines.append(line)
-      if line[-1:] == '\n':
-        line = line[:-1]
-      logger.info(line)
+      logger.info(line.rstrip('\n'))
     self.output = ''.join(output_lines)
 
 
@@ -168,11 +166,9 @@ def setFinished(pid_file):
 
 def write_pid(pid_file):
   logger = logging.getLogger('Slapgrid')
-  pid = os.getpid()
   try:
-    f = open(pid_file, 'w')
-    f.write('%s' % pid)
-    f.close()
+    with open(pid_file, 'w') as fout:
+      fout.write('%s' % os.getpid())
   except (IOError, OSError):
     logger.critical('slapgrid could not write pidfile %s' % pid_file)
     raise
@@ -302,9 +298,7 @@ def launchBuildout(path, buildout_binary,
   uid = stat_info.st_uid
   gid = stat_info.st_gid
   # Extract python binary to prevent shebang size limit
-  file = open(buildout_binary, 'r')
-  line = file.readline()
-  file.close()
+  line = open(buildout_binary, 'r').readline()
   invocation_list = []
   if line.startswith('#!'):
     line = line[2:]
@@ -341,11 +335,9 @@ def updateFile(file_path, content, mode=0o600):
   if not (os.path.isfile(file_path)) or \
      not(hashlib.md5(open(file_path).read()).digest() ==\
          hashlib.md5(content).digest()):
+    with open(file_path, 'w') as fout:
+      fout.write(content)
     altered = True
-    file_file = open(file_path, 'w')
-    file_file.write(content)
-    file_file.flush()
-    file_file.close()
   os.chmod(file_path, stat.S_IREAD | stat.S_IWRITE | stat.S_IEXEC)
   if stat.S_IMODE(os.stat(file_path).st_mode) != mode:
     os.chmod(file_path, mode)