pylint: adjust for consider-using-with

Either apply suggestion, or disable warning, depending on context.

qubes/backup.py

@@ -187,6 +187,7 @@ def set_ctty(ctty_fd, master_fd):
         stderr=stderr,
         preexec_fn=lambda: set_ctty(pty_slave, pty_master))
     os.close(pty_slave)
+    # pylint: disable=consider-using-with
     return p, open(pty_master, 'wb+', buffering=0)
 
 

qubes/dochelpers.py

@@ -70,12 +70,12 @@ def fetch_ticket_info(app, number):
     :raises: urllib.error.HTTPError
     """
 
-    response = urllib.request.urlopen(urllib.request.Request(
-        app.config.ticket_base_uri.format(number=number),
-        headers={
-            'Accept': 'application/vnd.github.v3+json',
-            'User-agent': __name__}))
-    return GithubTicket(json.load(response))
+    with urllib.request.urlopen(urllib.request.Request(
+            app.config.ticket_base_uri.format(number=number),
+            headers={
+                'Accept': 'application/vnd.github.v3+json',
+                'User-agent': __name__})) as response:
+        return GithubTicket(json.load(response))
 
 
 def ticket(name, rawtext, text, lineno, inliner, options=None, content=None):

qubes/ext/pci.py

@@ -258,9 +258,9 @@ def on_device_pre_detached_pci(self, vm, event, device):
         # qubes.DetachPciDevice, which unbinds driver, not to oops the kernel
 
         device = _cache_get(device.backend_domain, device.ident)
-        p = subprocess.Popen(['xl', 'pci-list', str(vm.xid)],
-                stdout=subprocess.PIPE)
-        result = p.communicate()[0].decode()
+        with subprocess.Popen(['xl', 'pci-list', str(vm.xid)],
+                stdout=subprocess.PIPE) as p:
+            result = p.communicate()[0].decode()
         m = re.search(r'^(\d+.\d+)\s+0000:{}$'.format(device.ident.replace(
             '_', ':')),
             result,

qubes/rngdoc.py

@@ -192,7 +192,8 @@ def write_rst_table(stream, itr, heads):
 
 
 def main(filename, example):
-    schema = Schema(lxml.etree.parse(open(filename, 'rb')))
+    with open(filename, 'rb') as schema_f:
+        schema = Schema(lxml.etree.parse(schema_f))
 
     sys.stdout.write(make_rst_section('Qubes XML specification', '='))
     sys.stdout.write('''

qubes/storage/file.py

@@ -315,9 +315,9 @@ def resize(self, size):  # pylint: disable=invalid-overridden-method
         with open(self.path, 'a+b') as fd:
             fd.truncate(size)
 
-        p = subprocess.Popen(['losetup', '--associated', self.path],
-                             stdout=subprocess.PIPE)
-        result = p.communicate()
+        with subprocess.Popen(['losetup', '--associated', self.path],
+                              stdout=subprocess.PIPE) as p:
+            result = p.communicate()
 
         m = re.match(r'^(/dev/loop\d+):\s', result[0].decode())
         if m is not None:

qubes/storage/lvm.py

@@ -236,9 +236,9 @@ def _parse_lvm_cache(lvm_output):
 def init_cache(log=logging.getLogger('qubes.storage.lvm')):
     cmd = _init_cache_cmd
     environ={'LC_ALL': 'C.UTF-8', **os.environ}
-    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
-        close_fds=True, env=environ)
-    out, err = p.communicate()
+    with subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE,
+            close_fds=True, env=environ) as p:
+        out, err = p.communicate()
     return_code = p.returncode
     if return_code == 0 and err:
         log.warning(err)

qubes/tarwriter.py

@@ -149,28 +149,27 @@ def main(args=None):
     parser.add_argument('output_file', default='-', nargs='?',
         help='output file name')
     args = parser.parse_args(args)
-    input_file = io.open(args.input_file, 'rb')
-    sparse_map = list(get_sparse_map(input_file))
-    header_name = args.input_file
-    if args.override_name:
-        header_name = args.override_name
-    tar_info = TarSparseInfo(header_name, sparse_map)
-    if args.output_file == '-':
-        output = io.open('/dev/stdout', 'wb')
-    else:
-        output = io.open(args.output_file, 'wb')
-    if args.use_compress_program:
-        compress = subprocess.Popen([args.use_compress_program],
-            stdin=subprocess.PIPE, stdout=output)
-        output = compress.stdin
-    else:
-        compress = None
-    output.write(tar_info.tobuf(tarfile.PAX_FORMAT))
-    copy_sparse_data(input_file, output, sparse_map)
-    finalize(output)
-    input_file.close()
-    output.close()
+    with io.open(args.input_file, 'rb') as input_file:
+        sparse_map = list(get_sparse_map(input_file))
+        header_name = args.input_file
+        if args.override_name:
+            header_name = args.override_name
+        tar_info = TarSparseInfo(header_name, sparse_map)
+        with io.open(('/dev/stdout' if args.output_file == '-'
+                      else args.output_file),
+                     'wb') as output:
+            if args.use_compress_program:
+                # pylint: disable=consider-using-with
+                compress = subprocess.Popen([args.use_compress_program],
+                    stdin=subprocess.PIPE, stdout=output)
+                output = compress.stdin
+            else:
+                compress = None
+            output.write(tar_info.tobuf(tarfile.PAX_FORMAT))
+            copy_sparse_data(input_file, output, sparse_map)
+            finalize(output)
     if compress is not None:
+        compress.stdin.close()
         compress.wait()
         return compress.returncode
     return 0

qubes/tools/__init__.py

@@ -515,11 +515,11 @@ def print_table(table):
 
     # for tests...
     if sys.stdout != sys.__stdout__:
-        p = subprocess.Popen(cmd + ['-c', '80'], stdin=subprocess.PIPE,
-            stdout=subprocess.PIPE)
-        p.stdin.write(text_table.encode())
-        (out, _) = p.communicate()
+        with subprocess.Popen(cmd + ['-c', '80'], stdin=subprocess.PIPE,
+                              stdout=subprocess.PIPE) as p:
+            p.stdin.write(text_table.encode())
+            (out, _) = p.communicate()
         sys.stdout.write(out.decode())
     else:
-        p = subprocess.Popen(cmd, stdin=subprocess.PIPE)
-        p.communicate(text_table.encode())
+        with subprocess.Popen(cmd, stdin=subprocess.PIPE) as p:
+            p.communicate(text_table.encode())

qubes/tools/qmemmand.py

@@ -94,6 +94,7 @@ def domain_list_changed(self, refresh_only=False):
         got_lock = False
         if not refresh_only:
             self.log.debug('acquiring global_lock')
+            # pylint: disable=consider-using-with
             global_lock.acquire()
             got_lock = True
             self.log.debug('global_lock acquired')
@@ -148,23 +149,21 @@ def meminfo_changed(self, domain_id):
             return
 
         self.log.debug('acquiring global_lock')
-        global_lock.acquire()
-        self.log.debug('global_lock acquired')
-        try:
-            global force_refresh_domain_list
-            if force_refresh_domain_list:
-                self.domain_list_changed(refresh_only=True)
-                force_refresh_domain_list = False
-            if domain_id not in self.watch_token_dict:
-                # domain just destroyed
-                return
+        with global_lock:
+            self.log.debug('global_lock acquired')
+            try:
+                global force_refresh_domain_list
+                if force_refresh_domain_list:
+                    self.domain_list_changed(refresh_only=True)
+                    force_refresh_domain_list = False
+                if domain_id not in self.watch_token_dict:
+                    # domain just destroyed
+                    return
 
-            system_state.refresh_meminfo(domain_id, untrusted_meminfo_key)
-        except:  # pylint: disable=bare-except
-            self.log.exception('Updating meminfo for %d failed', domain_id)
-        finally:
-            global_lock.release()
-            self.log.debug('global_lock released')
+                system_state.refresh_meminfo(domain_id, untrusted_meminfo_key)
+            except:  # pylint: disable=bare-except
+                self.log.exception('Updating meminfo for %d failed', domain_id)
+        self.log.debug('global_lock released')
 
     def watch_loop(self):
         self.log.debug('watch_loop()')
@@ -206,6 +205,7 @@ def handle(self):
                     return
 
                 self.log.debug('acquiring global_lock')
+                # pylint: disable=consider-using-with
                 global_lock.acquire()
                 self.log.debug('global_lock acquired')
 

qubes/utils.py

@@ -52,10 +52,10 @@ def get_timezone():
     if not tz_info:
         return None
     if tz_info.st_nlink > 1:
-        p = subprocess.Popen(['find', '/usr/share/zoneinfo',
-            '-inum', str(tz_info.st_ino), '-print', '-quit'],
-            stdout=subprocess.PIPE)
-        tz_path = p.communicate()[0].strip()
+        with subprocess.Popen(['find', '/usr/share/zoneinfo',
+                '-inum', str(tz_info.st_ino), '-print', '-quit'],
+                stdout=subprocess.PIPE) as p:
+            tz_path = p.communicate()[0].strip()
         return tz_path.replace(b'/usr/share/zoneinfo/', b'')
     return None