# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
from __future__ import print_function
import difflib
import imp
import os
import shlex
import subprocess
import sys
import time
import warnings
from django.core.management.templates import BaseCommand # noqa
# Suppress DeprecationWarnings which clutter the output to the point of
# rendering it unreadable.
warnings.simplefilter('ignore')
[docs]def get_module_path(module_name):
"""Gets the module path without importing anything.
Avoids conflicts with package dependencies.
(taken from http://github.com/sitkatech/pypatch)
"""
path = sys.path
for name in module_name.split('.'):
file_pointer, path, desc = imp.find_module(name, path)
path = [path, ]
if file_pointer is not None:
file_pointer.close()
return path[0]
[docs]class DirContext(object):
"""Change directory in a context manager.
This allows changing directory and to always fall back to the previous
directory whatever happens during execution.
Usage::
with DirContext('/home/foo') as dircontext:
# Some code happening in '/home/foo'
# We are back to the previous directory.
"""
def __init__(self, dirname):
self.prevdir = os.path.abspath(os.curdir)
os.chdir(dirname)
self.curdir = os.path.abspath(os.curdir)
def __enter__(self):
return self
def __exit__(self, exc_type, exc_value, traceback):
os.chdir(self.prevdir)
def __str__(self):
return self.curdir
[docs]class Command(BaseCommand):
[docs] def add_arguments(self, parser):
parser.add_argument(
'--gendiff',
action='store_true',
dest='gendiff',
default=False,
help=('Generate a diff file between local_settings.py and '
'local_settings.py.example'),
)
parser.add_argument(
'-f', '--force',
action='store_true',
dest='force',
default=False,
help=('Force destination rewriting without warning if the '
'destination file already exists.'),
)
help = ("Creates a local_settings.py file from the "
"local_settings.py.example template.")
time_fmt = '%Y-%m-%d %H:%M:%S %Z'
file_time_fmt = '%Y%m%d%H%M%S%Z'
local_settings_example = 'local_settings.py.example'
local_settings_file = 'local_settings.py'
local_settings_diff = 'local_settings.diff'
local_settings_reject_pattern = 'local_settings.py_%s.rej'
def __init__(self, *args, **kwargs):
super(Command, self).__init__(*args, **kwargs)
settings_file = os.path.abspath(
get_module_path(os.environ['DJANGO_SETTINGS_MODULE'])
)
self.local_settings_dir = os.path.abspath(
os.path.join(
os.path.realpath(os.path.dirname(settings_file)),
'local'
)
)
[docs] def gendiff(self, force=False):
"""Generate a diff between self.local_settings and the example file.
"""
with DirContext(self.local_settings_dir) as dircontext:
if not os.path.exists(self.local_settings_diff) or force:
with open(self.local_settings_example, 'r') as fp:
example_lines = fp.readlines()
with open(self.local_settings_file, 'r') as fp:
local_settings_lines = fp.readlines()
local_settings_example_mtime = time.strftime(
self.time_fmt,
time.localtime(
os.stat(self.local_settings_example).st_mtime)
)
local_settings_mtime = time.strftime(
self.time_fmt,
time.localtime(os.stat(self.local_settings_file).st_mtime)
)
print('generating "%s"...' % os.path.join(
dircontext.curdir,
self.local_settings_diff)
)
with open(self.local_settings_diff, 'w') as fp:
for line in difflib.unified_diff(
example_lines, local_settings_lines,
fromfile=self.local_settings_example,
tofile=self.local_settings_file,
fromfiledate=local_settings_example_mtime,
tofiledate=local_settings_mtime
):
fp.write(line)
print('\tDONE.')
sys.exit(0)
else:
sys.exit(
'"%s" already exists.' %
os.path.join(dircontext.curdir,
self.local_settings_diff)
)
[docs] def patch(self, force=False):
"""Patch local_settings.py.example with local_settings.diff.
The patch application generates the local_settings.py file (the
local_settings.py.example remains unchanged).
http://github.com/sitkatech/pypatch fails if the
local_settings.py.example file is not 100% identical to the one used to
generate the first diff so we use the patch command instead.
"""
with DirContext(self.local_settings_dir) as dircontext:
if os.path.exists(self.local_settings_diff):
if not os.path.exists(self.local_settings_file) or force:
local_settings_reject = \
self.local_settings_reject_pattern % (
time.strftime(self.file_time_fmt, time.localtime())
)
patch_cmd = shlex.split(
'patch %s %s -o %s -r %s' % (
self.local_settings_example,
self.local_settings_diff,
self.local_settings_file,
local_settings_reject
)
)
try:
subprocess.check_call(patch_cmd)
except subprocess.CalledProcessError:
if os.path.exists(local_settings_reject):
sys.exit(
'Some conflict(s) occurred. Please check "%s" '
'to find unapplied parts of the diff.\n'
'Once conflicts are solved, it is safer to '
'regenerate a newer diff with the "--gendiff" '
'option.' %
os.path.join(
dircontext.curdir,
local_settings_reject)
)
else:
sys.exit('An unhandled error occurred.')
print('Generation of "%s" successful.' % os.path.join(
dircontext.curdir,
self.local_settings_file)
)
sys.exit(0)
else:
sys.exit(
'"%s" already exists.' %
os.path.join(dircontext.curdir,
self.local_settings_file)
)
else:
sys.exit('No diff file found, please generate one with the '
'"--gendiff" option.')
[docs] def handle(self, *args, **options):
force = options.get('force')
if options.get('gendiff'):
self.gendiff(force)
else:
self.patch(force)