Refactor: use lazy logging

As described in pep282 [1], the variable part of a log message
should be passed in via parameter.  In this case the parameters
are evaluated only when they need to be.

This patch fixes (unifies) this for DIB.

A check using pylint was added that this kind of passing parameters to
the logging subsystem is enforced in future.  As a blueprint a similar
(stripped-down) approach from cinder [2] was used.

[1] https://www.python.org/dev/peps/pep-0282/
[2] https://github.com/openstack/cinder/blob/master/tox.ini

Change-Id: I2d7bcc863e4e9583d82d204438b3c781ac99824e
Signed-off-by: Andreas Florath <andreas@florath.net>

diskimage_builder/block_device/blockdevice.py

@@ -133,7 +133,7 @@ class BlockDevice(object):
         logger.debug("Creating BlockDevice object")
 
         self.params = params
-        logger.debug("Params [%s]" % self.params)
+        logger.debug("Params [%s]", self.params)
 
         self.state_dir = os.path.join(
             self.params['build-dir'], "states/block-device")
@@ -153,7 +153,7 @@ class BlockDevice(object):
             pass
 
     def write_state(self, state):
-        logger.debug("Write state [%s]" % self.state_json_file_name)
+        logger.debug("Write state [%s]", self.state_json_file_name)
         with open(self.state_json_file_name, "w") as fd:
             json.dump(state, fd)
 
@@ -171,16 +171,16 @@ class BlockDevice(object):
         """
         with open(self.params['config'], "rt") as config_fd:
             self.config = yaml.safe_load(config_fd)
-        logger.debug("Config before merge [%s]" % self.config)
+        logger.debug("Config before merge [%s]", self.config)
         self.config = config_tree_to_graph(self.config)
-        logger.debug("Config before merge [%s]" % self.config)
+        logger.debug("Config before merge [%s]", self.config)
         self._merge_into_config()
-        logger.debug("Final config [%s]" % self.config)
+        logger.debug("Final config [%s]", self.config)
         # Write the final config
         with open(self.config_json_file_name, "wt") as fd:
             json.dump(self.config, fd)
-        logger.info("Wrote final block device config to [%s]"
-                    % self.config_json_file_name)
+        logger.info("Wrote final block device config to [%s]",
+                    self.config_json_file_name)
 
     def _config_get_mount(self, path):
         for entry in self.config:
@@ -214,17 +214,17 @@ class BlockDevice(object):
         Arguments:
         :param symbol: the symbol to get
         """
-        logger.info("Getting value for [%s]" % symbol)
+        logger.info("Getting value for [%s]", symbol)
         if symbol == "root-label":
             root_mount = self._config_get_mount("/")
             root_fs = self._config_get_mkfs(root_mount['base'])
-            logger.debug("root-label [%s]" % root_fs['label'])
+            logger.debug("root-label [%s]", root_fs['label'])
             print("%s" % root_fs['label'])
             return 0
         if symbol == "root-fstype":
             root_mount = self._config_get_mount("/")
             root_fs = self._config_get_mkfs(root_mount['base'])
-            logger.debug("root-fstype [%s]" % root_fs['type'])
+            logger.debug("root-fstype [%s]", root_fs['type'])
             print("%s" % root_fs['type'])
             return 0
         if symbol == 'mount-points':
@@ -246,7 +246,7 @@ class BlockDevice(object):
             print("%s" % self.state['blockdev']['image0']['image'])
             return 0
 
-        logger.error("Invalid symbol [%s] for getval" % symbol)
+        logger.error("Invalid symbol [%s] for getval", symbol)
         return 1
 
     def cmd_writefstab(self):
@@ -257,7 +257,7 @@ class BlockDevice(object):
         with open(tmp_fstab, "wt") as fstab_fd:
             # This gives the order in which this must be mounted
             for mp in self.state['mount_order']:
-                logger.debug("Writing fstab entry for [%s]" % mp)
+                logger.debug("Writing fstab entry for [%s]", mp)
                 fs_base = self.state['mount'][mp]['base']
                 fs_name = self.state['mount'][mp]['name']
                 fs_val = self.state['filesys'][fs_base]
@@ -290,7 +290,7 @@ class BlockDevice(object):
         """Creates the block device"""
 
         logger.info("create() called")
-        logger.debug("Using config [%s]" % self.config)
+        logger.debug("Using config [%s]", self.config)
 
         self.state = {}
         rollback = []
@@ -335,7 +335,7 @@ class BlockDevice(object):
         for node in reverse_order:
             node.cleanup(self.state)
 
-        logger.info("Removing temporary dir [%s]" % self.state_dir)
+        logger.info("Removing temporary dir [%s]", self.state_dir)
         shutil.rmtree(self.state_dir)
 
         return 0
@@ -350,7 +350,7 @@ class BlockDevice(object):
         for node in reverse_order:
             node.delete(self.state)
 
-        logger.info("Removing temporary dir [%s]" % self.state_dir)
+        logger.info("Removing temporary dir [%s]", self.state_dir)
         shutil.rmtree(self.state_dir)
 
         return 0

diskimage_builder/block_device/cmd.py

@@ -101,7 +101,7 @@ class BlockDeviceCmd(object):
                     "DIB_BLOCK_DEVICE_PARAMS_YAML or --params not set")
         else:
             param_file = self.args.params
-            logger.info("params [%s]" % param_file)
+            logger.info("params [%s]", param_file)
         try:
             with open(param_file) as f:
                 self.params = yaml.safe_load(f)

diskimage_builder/block_device/config.py

@@ -160,7 +160,7 @@ def create_graph(config, default_config):
         # this should have been checked by generate_config
         assert len(config_entry) == 1
 
-        logger.debug("Config entry [%s]" % config_entry)
+        logger.debug("Config entry [%s]", config_entry)
         cfg_obj_name = list(config_entry.keys())[0]
         cfg_obj_val = config_entry[cfg_obj_name]
 

diskimage_builder/block_device/level0/localloop.py

@@ -34,14 +34,14 @@ class LocalLoopNode(NodeBase):
     """
     def __init__(self, config, default_config):
         logger.debug("Creating LocalLoop object; config [%s] "
-                     "default_config [%s]" % (config, default_config))
+                     "default_config [%s]", config, default_config)
         super(LocalLoopNode, self).__init__(config['name'])
         if 'size' in config:
             self.size = parse_abs_size_spec(config['size'])
-            logger.debug("Image size [%s]" % self.size)
+            logger.debug("Image size [%s]", self.size)
         else:
             self.size = parse_abs_size_spec(default_config['image-size'])
-            logger.debug("Using default image size [%s]" % self.size)
+            logger.debug("Using default image size [%s]", self.size)
         if 'directory' in config:
             self.image_dir = config['directory']
         else:
@@ -54,14 +54,14 @@ class LocalLoopNode(NodeBase):
 
     @staticmethod
     def image_create(filename, size):
-        logger.info("Create image file [%s]" % filename)
+        logger.info("Create image file [%s]", filename)
         with open(filename, "w") as fd:
             fd.seek(size - 1)
             fd.write("\0")
 
     @staticmethod
     def _image_delete(filename):
-        logger.info("Remove image file [%s]" % filename)
+        logger.info("Remove image file [%s]", filename)
         os.remove(filename)
 
     @staticmethod
@@ -74,7 +74,7 @@ class LocalLoopNode(NodeBase):
         if rval == 0:
             # [:-1]: Cut of the newline
             block_device = subp.stdout.read()[:-1].decode("utf-8")
-            logger.info("New block device [%s]" % block_device)
+            logger.info("New block device [%s]", block_device)
             return block_device
         else:
             logger.error("losetup failed")
@@ -91,18 +91,18 @@ class LocalLoopNode(NodeBase):
                                      loopdev])
             rval = subp.wait()
             if rval == 0:
-                logger.info("Successfully detached [%s]" % loopdev)
+                logger.info("Successfully detached [%s]", loopdev)
                 return 0
             else:
                 logger.error("loopdev detach failed")
                 # Do not raise an error - maybe other cleanup methods
                 # can at least do some more work.
-        logger.debug("Gave up trying to detach [%s]" % loopdev)
+        logger.debug("Gave up trying to detach [%s]", loopdev)
         return rval
 
     def create(self, result, rollback):
-        logger.debug("[%s] Creating loop on [%s] with size [%d]" %
-                     (self.name, self.filename, self.size))
+        logger.debug("[%s] Creating loop on [%s] with size [%d]",
+                     self.name, self.filename, self.size)
 
         rollback.append(lambda: self._image_delete(self.filename))
         self.image_create(self.filename, self.size)
@@ -115,8 +115,8 @@ class LocalLoopNode(NodeBase):
 
         result['blockdev'][self.name] = {"device": block_device,
                                          "image": self.filename}
-        logger.debug("Created loop  name [%s] device [%s] image [%s]"
-                     % (self.name, block_device, self.filename))
+        logger.debug("Created loop  name [%s] device [%s] image [%s]",
+                     self.name, block_device, self.filename)
         return
 
     def umount(self, state):

diskimage_builder/block_device/level1/mbr.py

@@ -190,8 +190,8 @@ class MBR(object):
         head = (lba // MBR.sectors_per_track) % MBR.heads_per_cylinder
         sector = (lba % MBR.sectors_per_track) + 1
 
-        logger.debug("Convert LBA to CHS [%d] -> [%d, %d, %d]"
-                     % (lba, cylinder, head, sector))
+        logger.debug("Convert LBA to CHS [%d] -> [%d, %d, %d]",
+                     lba, cylinder, head, sector)
         return cylinder, head, sector
 
     def encode_chs(self, cylinders, heads, sectors):
@@ -212,8 +212,8 @@ class MBR(object):
         es = es | hc          # pass them into the top two bits of the sector
 
         logger.debug("Encode CHS to disk format [%d %d %d] "
-                     "-> [%02x %02x %02x]" % (cylinders, heads, sectors,
-                                              eh, es, ec))
+                     "-> [%02x %02x %02x]", cylinders, heads, sectors,
+                     eh, es, ec)
         return eh, es, ec
 
     def write_mbr(self):
@@ -246,8 +246,8 @@ class MBR(object):
         and also the EBR use the same format.
         """
         logger.info("Write partition entry blockno [%d] entry [%d] "
-                    "start [%d] length [%d]" % (blockno, entry,
-                                                lba_start, lba_length))
+                    "start [%d] length [%d]", blockno, entry,
+                    lba_start, lba_length)
 
         self.image_fd.seek(
             blockno * MBR.bytes_per_sector +
@@ -290,9 +290,9 @@ class MBR(object):
         lba_abs_partition_end \
             = self.align(lba_partition_abs_start + lba_partition_length)
         logger.info("Partition absolute [%d] relative [%d] "
-                    "length [%d] absolute end [%d]"
-                    % (lba_partition_abs_start, lba_partition_rel_start,
-                       lba_partition_length, lba_abs_partition_end))
+                    "length [%d] absolute end [%d]",
+                    lba_partition_abs_start, lba_partition_rel_start,
+                    lba_partition_length, lba_abs_partition_end)
         return lba_partition_abs_start, lba_partition_length, \
             lba_abs_partition_end
 
@@ -305,14 +305,14 @@ class MBR(object):
             self.align(lba_partition_abs_start), lba_partition_length)
 
         self.partition_abs_next_free = lba_abs_partition_end
-        logger.debug("Next free [%d]" % self.partition_abs_next_free)
+        logger.debug("Next free [%d]", self.partition_abs_next_free)
         self.primary_partitions_created += 1
         self.partition_number += 1
         return self.partition_number
 
     def add_extended_partition(self, bootflag, size, ptype):
         lba_ebr_abs = self.partition_abs_next_free
-        logger.info("EBR block absolute [%d]" % lba_ebr_abs)
+        logger.info("EBR block absolute [%d]", lba_ebr_abs)
 
         _, lba_partition_length, lba_abs_partition_end \
             = self.compute_partition_lbas(lba_ebr_abs + 1, size)
@@ -332,7 +332,7 @@ class MBR(object):
         self.write_mbr_signature(lba_ebr_abs)
 
         self.partition_abs_next_free = lba_abs_partition_end
-        logger.debug("Next free [%d]" % self.partition_abs_next_free)
+        logger.debug("Next free [%d]", self.partition_abs_next_free)
         self.disk_block_last_ref = lba_ebr_abs
         self.extended_partitions_created += 1
         self.partition_number += 1
@@ -341,8 +341,8 @@ class MBR(object):
     def add_partition(self, primaryflag, bootflag, size, ptype):
         """Adds a partition with the given type and size"""
         logger.debug("Add new partition primary [%s] boot [%s] "
-                     "size [%d] type [%x]" %
-                     (primaryflag, bootflag, size, ptype))
+                     "size [%d] type [%x]",
+                     primaryflag, bootflag, size, ptype)
 
         # primaries must be created before extended
         if primaryflag and self.extended_partitions_created > 0:

diskimage_builder/block_device/level1/partitioning.py

@@ -33,7 +33,7 @@ logger = logging.getLogger(__name__)
 class Partitioning(PluginBase):
 
     def __init__(self, config, default_config):
-        logger.debug("Creating Partitioning object; config [%s]" % config)
+        logger.debug("Creating Partitioning object; config [%s]", config)
         super(Partitioning, self).__init__()
 
         # Because using multiple partitions of one base is done
@@ -91,13 +91,13 @@ class Partitioning(PluginBase):
 
     def _all_part_devices_exist(self, expected_part_devices):
         for part_device in expected_part_devices:
-            logger.debug("Checking if partition device [%s] exists" %
+            logger.debug("Checking if partition device [%s] exists",
                          part_device)
             if not os.path.exists(part_device):
-                logger.info("Partition device [%s] does not exists"
-                            % part_device)
+                logger.info("Partition device [%s] does not exists",
+                            part_device)
                 return False
-            logger.debug("Partition already exists [%s]" % part_device)
+            logger.debug("Partition already exists [%s]", part_device)
         return True
 
     def _notify_os_of_partition_changes(self, device_path, partition_devices):
@@ -112,7 +112,7 @@ class Partitioning(PluginBase):
             exec_sudo(["partprobe", device_path])
             exec_sudo(["udevadm", "settle"])
         except CalledProcessError as e:
-            logger.info("Ignoring settling failure: %s" % e)
+            logger.info("Ignoring settling failure: %s", e)
             pass
 
         if self._all_part_devices_exist(partition_devices):
@@ -133,8 +133,8 @@ class Partitioning(PluginBase):
         # created are calling back into this.
         image_path = result['blockdev'][self.base]['image']
         device_path = result['blockdev'][self.base]['device']
-        logger.info("Creating partition on [%s] [%s]" %
-                    (self.base, image_path))
+        logger.info("Creating partition on [%s] [%s]",
+                    self.base, image_path)
 
         # This is a bit of a hack.  Each of the partitions is actually
         # in the graph, so for every partition we get a create() call
@@ -158,14 +158,14 @@ class Partitioning(PluginBase):
                 part_size = part_cfg.get_size()
                 part_free = part_impl.free()
                 part_type = part_cfg.get_type()
-                logger.debug("Not partitioned space [%d]" % part_free)
+                logger.debug("Not partitioned space [%d]", part_free)
                 part_size = parse_rel_size_spec(part_size,
                                                 part_free)[1]
                 part_no \
                     = part_impl.add_partition(part_primary, part_bootflag,
                                               part_size, part_type)
-                logger.debug("Create partition [%s] [%d]" %
-                             (part_name, part_no))
+                logger.debug("Create partition [%s] [%d]",
+                             part_name, part_no)
                 partition_device_name = device_path + "p%d" % part_no
                 result['blockdev'][part_name] \
                     = {'device': partition_device_name}

diskimage_builder/block_device/level2/mkfs.py

@@ -44,7 +44,7 @@ file_system_max_label_length = {
 class FilesystemNode(NodeBase):
 
     def __init__(self, config):
-        logger.debug("Create filesystem object; config [%s]" % config)
+        logger.debug("Create filesystem object; config [%s]", config)
         super(FilesystemNode, self).__init__(config['name'])
 
         # Parameter check (mandatory)
@@ -85,8 +85,8 @@ class FilesystemNode(NodeBase):
                         'max': file_system_max_label_length[self.type]}))
         else:
             logger.warning("Length of label [%s] cannot be checked for "
-                           "filesystem [%s]: unknown max length" %
-                           (self.label, self.type))
+                           "filesystem [%s]: unknown max length",
+                           self.label, self.type)
             logger.warning("Continue - but this might lead to an error")
 
         if self.opts is not None:
@@ -95,7 +95,7 @@ class FilesystemNode(NodeBase):
         if self.uuid is None:
             self.uuid = str(uuid.uuid4())
 
-        logger.debug("Filesystem created [%s]" % self)
+        logger.debug("Filesystem created [%s]", self)
 
     def get_edges(self):
         edge_from = [self.base]
@@ -103,7 +103,7 @@ class FilesystemNode(NodeBase):
         return (edge_from, edge_to)
 
     def create(self, result, rollback):
-        logger.info("create called; result [%s]" % result)
+        logger.info("create called; result [%s]", result)
 
         cmd = ["mkfs"]
 
@@ -117,8 +117,8 @@ class FilesystemNode(NodeBase):
         elif self.type == 'xfs':
             cmd.extend(['-m', "uuid=%s" % self.uuid])
         else:
-            logger.warning("UUID will not be written for fs type [%s]"
-                           % self.type)
+            logger.warning("UUID will not be written for fs type [%s]",
+                           self.type)
 
         if self.type in ('ext2', 'ext3', 'ext4', 'xfs'):
             cmd.append('-q')
@@ -128,7 +128,7 @@ class FilesystemNode(NodeBase):
         device = result['blockdev'][self.base]['device']
         cmd.append(device)
 
-        logger.debug("Creating fs command [%s]" % (cmd))
+        logger.debug("Creating fs command [%s]", cmd)
         exec_sudo(cmd)
 
         if 'filesys' not in result:

diskimage_builder/block_device/level3/mount.py

@@ -45,7 +45,7 @@ class MountPointNode(NodeBase):
                 raise BlockDeviceSetupException(
                     "MountPoint config needs [%s]" % pname)
             setattr(self, pname, config[pname])
-        logger.debug("MountPoint created [%s]" % self)
+        logger.debug("MountPoint created [%s]", self)
 
     def get_node(self):
         global mount_points
@@ -53,7 +53,7 @@ class MountPointNode(NodeBase):
             raise BlockDeviceSetupException(
                 "Mount point [%s] specified more than once"
                 % self.mount_point)
-        logger.debug("Insert node [%s]" % self)
+        logger.debug("Insert node [%s]", self)
         mount_points[self.mount_point] = self
         return self
 
@@ -77,9 +77,9 @@ class MountPointNode(NodeBase):
         global mount_points
         global sorted_mount_points
         if sorted_mount_points is None:
-            logger.debug("Mount points [%s]" % mount_points)
+            logger.debug("Mount points [%s]", mount_points)
             sorted_mount_points = sort_mount_points(mount_points.keys())
-            logger.info("Sorted mount points [%s]" % (sorted_mount_points))
+            logger.info("Sorted mount points [%s]", sorted_mount_points)
 
         # Look for the occurance in the list
         mpi = sorted_mount_points.index(self.mount_point)
@@ -92,8 +92,8 @@ class MountPointNode(NodeBase):
         return (edge_from, edge_to)
 
     def create(self, result, rollback):
-        logger.debug("mount called [%s]" % self.mount_point)
-        logger.debug("result [%s]" % result)
+        logger.debug("mount called [%s]", self.mount_point)
+        logger.debug("result [%s]", result)
         rel_mp = self.mount_point if self.mount_point[0] != '/' \
                  else self.mount_point[1:]
         mount_point = os.path.join(self.mount_base, rel_mp)
@@ -101,7 +101,7 @@ class MountPointNode(NodeBase):
             # Need to sudo this because of permissions in the new
             # file system tree.
             exec_sudo(['mkdir', '-p', mount_point])
-        logger.info("Mounting [%s] to [%s]" % (self.name, mount_point))
+        logger.info("Mounting [%s] to [%s]", self.name, mount_point)
         exec_sudo(["mount", result['filesys'][self.base]['device'],
                    mount_point])
 
@@ -115,7 +115,7 @@ class MountPointNode(NodeBase):
         result['mount_order'].append(self.mount_point)
 
     def umount(self, state):
-        logger.info("Called for [%s]" % self.name)
+        logger.info("Called for [%s]", self.name)
         exec_sudo(["umount", state['mount'][self.mount_point]['path']])
 
     def delete(self, state):

diskimage_builder/block_device/level4/fstab.py

@@ -35,8 +35,8 @@ class FstabNode(NodeBase):
         return (edge_from, edge_to)
 
     def create(self, result, rollback):
-        logger.debug("fstab create called [%s]" % self.name)
-        logger.debug("result [%s]" % result)
+        logger.debug("fstab create called [%s]", self.name)
+        logger.debug("result [%s]", result)
 
         if 'fstab' not in result:
             result['fstab'] = {}

diskimage_builder/block_device/utils.py

@@ -104,7 +104,7 @@ def exec_sudo(cmd):
     sudo_cmd = ["sudo"]
     sudo_cmd.extend(cmd)
     try:
-        logger.info("Calling [%s]" % " ".join(sudo_cmd))
+        logger.info("Calling [%s]", " ".join(sudo_cmd))
     except TypeError:
         # Popen actually doesn't care, but we've managed to get mixed
         # str and bytes in argument lists which causes errors logging
@@ -117,7 +117,7 @@ def exec_sudo(cmd):
                             stderr=subprocess.STDOUT)
 
     for line in iter(proc.stdout.readline, b""):
-        logger.debug("exec_sudo: %s" % line.rstrip())
+        logger.debug("exec_sudo: %s", line.rstrip())
 
     proc.wait()
     if proc.returncode != 0:
@@ -126,7 +126,7 @@ def exec_sudo(cmd):
 
 
 def sort_mount_points(mount_points):
-    logger.debug("sort_mount_points called [%s]" % mount_points)
+    logger.debug("sort_mount_points called [%s]", mount_points)
 
     def insert_sorted(mp, sorted_mount_points):
         if len(sorted_mount_points) == 0:
@@ -141,5 +141,5 @@ def sort_mount_points(mount_points):
     sorted_mount_points = []
     for mp in mount_points:
         insert_sorted(mp, sorted_mount_points)
-    logger.debug("sort_mount_points result [%s]" % sorted_mount_points)
+    logger.debug("sort_mount_points result [%s]", sorted_mount_points)
     return sorted_mount_points

diskimage_builder/element_dependencies.py

@@ -164,8 +164,8 @@ def _expand_element_dependencies(user_elements, all_elements):
         logger.error(
             "The following elements are already provided by another element")
         for element in conflicts:
-            logger.error("%s : already provided by %s" %
-                         (element, provided_by[element]))
+            logger.error("%s : already provided by %s",
+                         element, provided_by[element])
         raise AlreadyProvidedException()
 
     if "operating-system" not in provided:
@@ -200,7 +200,7 @@ def _find_all_elements(paths=None):
     else:
         paths = list(reversed(paths.split(':')))
 
-    logger.debug("ELEMENTS_PATH is: %s" % ":".join(paths))
+    logger.debug("ELEMENTS_PATH is: %s", ":".join(paths))
 
     for path in paths:
         if not os.path.isdir(path):

diskimage_builder/tests/functional/test_blockdevice.py

@@ -64,8 +64,8 @@ class TestBlockDevice(testtools.TestCase):
         logging.info("test_create_default_config called")
         builddir = self.useFixture(fixtures.TempDir()).path
         imagedir = self.useFixture(fixtures.TempDir()).path
-        logging.info("builddir [%s]" % builddir)
-        logging.info("imagedir [%s]" % imagedir)
+        logging.info("builddir [%s]", builddir)
+        logging.info("imagedir [%s]", imagedir)
 
         logging.info("Calling BlockDevice constructor")
         bd = self.useFixture(BlockDeviceFixture(
@@ -75,12 +75,12 @@ class TestBlockDevice(testtools.TestCase):
         bd.cmd_create()
 
         logging.info("Check result")
-        logging.info("State [%s]" % bd.state)
+        logging.info("State [%s]", bd.state)
         self.assertTrue('device' in bd.state['image0'])
         lb_dev = bd.state['image0']['device']
         # partprobe loopback so we can get partition info
         args = ['sudo', 'partprobe', lb_dev]
-        logging.info("Call: %s" % args)
+        logging.info("Call: %s", args)
         subprocess.check_call(args)
         bd.cmd_cleanup()
         self._assert_loopbacks_cleaned(bd)

diskimage_builder/tests/test_elementdeps.py

@@ -27,7 +27,7 @@ data_dir = os.path.abspath(
 
 
 def _populate_element(element_dir, element_name, element_deps=[], provides=[]):
-    logger.debug("Populate %s <%s>" % (element_name, element_dir))
+    logger.debug("Populate %s <%s>", element_name, element_dir)
     element_home = os.path.join(element_dir, element_name)
     os.mkdir(element_home)
     deps_path = os.path.join(element_home, 'element-deps')

pylint.cfg

@@ -2,6 +2,5 @@
 persistent=no
 
 [MESSAGES CONTROL]
-
 disable=all
-enable=bad-indentation
+enable=bad-indentation, logging-not-lazy

tox.ini

@@ -1,5 +1,5 @@
 [tox]
-envlist = py35,py27,pep8
+envlist = py35,py27,pep8,pylint
 minversion = 1.6
 skipsdist = True