diffido/diffido.py

776 sor
27 KiB
Python
Executable file

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""Diffido - because the F5 key is a terrible thing to waste.
Copyright 2018 Davide Alberani <da@erlug.linux.it>
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.
"""
import os
import re
import json
import pytz
import shutil
import urllib
import smtplib
from email.mime.text import MIMEText
import logging
import datetime
import requests
import subprocess
import multiprocessing
from lxml import etree
from xml.etree import ElementTree
from tornado.ioloop import IOLoop
from apscheduler.triggers.cron import CronTrigger
from apscheduler.schedulers.tornado import TornadoScheduler
from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
import tornado.httpserver
import tornado.ioloop
import tornado.options
from tornado.options import define, options
import tornado.web
from tornado import gen, escape
JOBS_STORE = 'sqlite:///conf/jobs.db'
API_VERSION = '1.0'
SCHEDULES_FILE = 'conf/schedules.json'
DEFAULT_CONF = 'conf/diffido.conf'
EMAIL_FROM = 'diffido@localhost'
SMTP_SETTINGS = {}
GIT_CMD = 'git'
re_commit = re.compile(r'^(?P<id>[0-9a-f]{40}) (?P<message>.*)\n(?: .* '
'(?P<insertions>\d+) insertion.* (?P<deletions>\d+) deletion.*$)?', re.M)
re_insertion = re.compile(r'(\d+) insertion')
re_deletion = re.compile(r'(\d+) deletion')
logger = logging.getLogger()
logger.setLevel(logging.INFO)
def read_schedules():
"""Return the schedules configuration.
:returns: dictionary from the JSON object in conf/schedules.json
:rtype: dict"""
if not os.path.isfile(SCHEDULES_FILE):
return {'schedules': {}}
try:
with open(SCHEDULES_FILE, 'r') as fd:
schedules = json.loads(fd.read())
for id_ in schedules.get('schedules', {}).keys():
schedule = schedules['schedules'][id_]
try:
schedule['last_history'] = get_last_history(id_)
except:
schedule['last_history'] = {}
continue
return schedules
except Exception as e:
logger.error('unable to read %s: %s' % (SCHEDULES_FILE, e))
return {'schedules': {}}
def write_schedules(schedules):
"""Write the schedules configuration.
:param schedules: the schedules to save
:type schedules: dict
:returns: True in case of success
:rtype: bool"""
try:
with open(SCHEDULES_FILE, 'w') as fd:
fd.write(json.dumps(schedules, indent=2))
except Exception as e:
logger.error('unable to write %s: %s' % (SCHEDULES_FILE, e))
return False
return True
def next_id(schedules):
"""Return the next available integer (as a string) in the list of schedules keys (do not fills holes)
:param schedules: the schedules
:type schedules: dict
:returns: the ID of the next schedule
:rtype: str"""
ids = schedules.get('schedules', {}).keys()
if not ids:
return '1'
return str(max([int(i) for i in ids]) + 1)
def get_schedule(id_, add_id=True, add_history=False):
"""Return information about a single schedule
:param id_: ID of the schedule
:type id_: str
:param add_id: if True, add the ID in the dictionary
:type add_id: bool
:returns: the schedule
:rtype: dict"""
try:
schedules = read_schedules()
except Exception:
return {}
data = schedules.get('schedules', {}).get(id_, {})
if add_history and data:
data['last_history'] = get_last_history(id_)
if add_id:
data['id'] = str(id_)
return data
def select_xpath(content, xpath):
"""Select a portion of a HTML document
:param content: the content of the document
:type content: str
:param xpath: the XPath selector
:type xpath: str
:returns: the selected document
:rtype: str"""
tree = etree.HTML(content)
elems = tree.xpath(xpath)
if not elems:
return content
selected_content = []
for elem in elems:
pieces = []
if elem.text:
pieces.append(elem.text)
for sub_el in elem.getchildren():
try:
sub_el_text = ElementTree.tostring(sub_el, method='html').decode('utf-8', 'replace')
except:
continue
if sub_el_text:
pieces.append(sub_el_text)
selected_content.append(''.join(pieces))
content = ''.join(selected_content).strip()
return content
def run_job(id_=None, force=False, *args, **kwargs):
"""Run a job
:param id_: ID of the schedule to run
:type id_: str
:param force: run even if disabled
:type force: bool
:param args: positional arguments
:type args: tuple
:param kwargs: named arguments
:type kwargs: dict
:returns: True in case of success
:rtype: bool"""
schedule = get_schedule(id_, add_id=False)
url = schedule.get('url')
if not url:
return False
logger.debug('running job id:%s title:%s url: %s' % (id_, schedule.get('title', ''), url))
if not schedule.get('enabled') and not force:
logger.info('not running job %s: disabled' % id_)
return True
req = requests.get(url, allow_redirects=True, timeout=(30.10, 240))
content = req.text
xpath = schedule.get('xpath')
if xpath:
try:
content = select_xpath(content, xpath)
except Exception as e:
logger.warn('unable to extract XPath %s: %s' % (xpath, e))
req_path = urllib.parse.urlparse(req.url).path
base_name = os.path.basename(req_path) or 'index.html'
def _commit(id_, filename, content, queue):
try:
os.chdir('storage/%s' % id_)
except Exception as e:
logger.info('unable to move to storage/%s directory: %s; trying to create it...' % (id_, e))
_created = False
try:
_created = git_create_repo(id_)
except Exception as e:
logger.info('unable to move to storage/%s directory: %s; unable to create it' % (id_, e))
if not _created:
return False
current_lines = 0
if os.path.isfile(filename):
with open(filename, 'r') as fd:
for line in fd:
current_lines += 1
with open(filename, 'w') as fd:
fd.write(content)
p = subprocess.Popen([GIT_CMD, 'add', filename])
p.communicate()
p = subprocess.Popen([GIT_CMD, 'commit', '-m', '%s' % datetime.datetime.utcnow(), '--allow-empty'],
stdout=subprocess.PIPE)
stdout, _ = p.communicate()
stdout = stdout.decode('utf-8')
insert = re_insertion.findall(stdout)
if insert:
insert = int(insert[0])
else:
insert = 0
delete = re_deletion.findall(stdout)
if delete:
delete = int(delete[0])
else:
delete = 0
queue.put({'insertions': insert, 'deletions': delete, 'previous_lines': current_lines,
'changes': max(insert, delete)})
queue = multiprocessing.Queue()
p = multiprocessing.Process(target=_commit, args=(id_, base_name, content, queue))
p.start()
res = queue.get()
p.join()
email = schedule.get('email')
if not email:
return True
changes = res.get('changes')
if not changes:
return True
min_change = schedule.get('minimum_change')
previous_lines = res.get('previous_lines')
if min_change and previous_lines:
min_change = float(min_change)
change_fraction = res.get('changes') / previous_lines
if change_fraction < min_change:
return True
# send notification
diff = get_diff(id_).get('diff')
if not diff:
return True
send_email(to=email, subject='%s page changed' % schedule.get('title'),
body='changes:\n\n%s' % diff)
return True
def safe_run_job(id_=None, *args, **kwargs):
"""Safely run a job, catching all the exceptions
:param id_: ID of the schedule to run
:type id_: str
:param args: positional arguments
:type args: tuple
:param kwargs: named arguments
:type kwargs: dict
:returns: True in case of success
:rtype: bool"""
try:
run_job(id_, *args, **kwargs)
except Exception as e:
send_email('error executing job %s: %s' % (id_, e))
def send_email(to, subject='diffido', body='', from_=None):
"""Send an email
:param to: destination address
:type to: str
:param subject: email subject
:type subject: str
:param body: body of the email
:type body: str
:param from_: sender address
:type from_: str
:returns: True in case of success
:rtype: bool"""
msg = MIMEText(body)
msg['Subject'] = subject
msg['From'] = from_ or EMAIL_FROM
msg['To'] = to
starttls = SMTP_SETTINGS.get('smtp-starttls')
use_ssl = SMTP_SETTINGS.get('smtp-use-ssl')
args = {}
for key, value in SMTP_SETTINGS.items():
if key in ('smtp-starttls', 'smtp-use-ssl'):
continue
if key in ('smtp-port'):
value = int(value)
key = key.replace('smtp-', '', 1).replace('-', '_')
args[key] = value
try:
if use_ssl:
with smtplib.SMTP_SSL(**args) as s:
s.send_message(msg)
else:
tls_args = {}
for key in ('ssl_keyfile', 'ssl_certfile', 'ssl_context'):
if key in args:
tls_args = args[key]
del args[key]
with smtplib.SMTP(**args) as s:
if starttls:
s.starttls(**tls_args)
s.ehlo_or_helo_if_needed()
s.send_message(msg)
except Exception as e:
logger.error('unable to send email to %s: %s' % (to, e))
return False
return True
def get_history(id_, limit=None, add_info=False):
"""Read the history of a schedule
:param id_: ID of the schedule
:type id_: str
:param limit: number of entries to fetch
:type limit: int
:param add_info: add information about the schedule itself
:type add_info: int
:returns: information about the schedule and its history
:rtype: dict"""
def _history(id_, limit, queue):
try:
os.chdir('storage/%s' % id_)
except Exception as e:
logger.info('unable to move to storage/%s directory: %s' % (id_, e))
return queue.put(b'')
cmd = [GIT_CMD, 'log', '--pretty=oneline', '--shortstat']
if limit is not None:
cmd.append('-%s' % limit)
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
stdout, _ = p.communicate()
queue.put(stdout)
queue = multiprocessing.Queue()
p = multiprocessing.Process(target=_history, args=(id_, limit, queue))
p.start()
res = queue.get().decode('utf-8')
p.join()
history = []
for match in re_commit.finditer(res):
info = match.groupdict()
info['insertions'] = int(info['insertions'] or 0)
info['deletions'] = int(info['deletions'] or 0)
info['changes'] = max(info['insertions'], info['deletions'])
history.append(info)
last_id = None
if history and 'id' in history[0]:
last_id = history[0]['id']
for idx, item in enumerate(history):
item['seq'] = idx + 1
data = {'history': history, 'last_id': last_id}
if add_info:
data['schedule'] = get_schedule(id_)
return data
def get_last_history(id_):
"""Read the last history entry of a schedule
:param id_: ID of the schedule
:type id_: str
:returns: information about the schedule and its history
:rtype: dict"""
history = get_history(id_, limit=1)
hist = history.get('history') or [{}]
return hist[0]
def get_diff(id_, commit_id='HEAD', old_commit_id=None):
"""Return the diff between commits of a schedule
:param id_: ID of the schedule
:type id_: str
:param commit_id: the most recent commit ID; HEAD by default
:type commit_id: str
:param old_commit_id: the older commit ID; if None, the previous commit is used
:type old_commit_id: str
:returns: information about the schedule and the diff between commits
:rtype: dict"""
def _history(id_, commit_id, old_commit_id, queue):
try:
os.chdir('storage/%s' % id_)
except Exception as e:
logger.info('unable to move to storage/%s directory: %s' % (id_, e))
return queue.put(b'')
p = subprocess.Popen([GIT_CMD, 'diff', old_commit_id or '%s~' % commit_id, commit_id],
stdout=subprocess.PIPE)
stdout, _ = p.communicate()
queue.put(stdout)
queue = multiprocessing.Queue()
p = multiprocessing.Process(target=_history, args=(id_, commit_id, old_commit_id, queue))
p.start()
res = queue.get().decode('utf-8')
p.join()
schedule = get_schedule(id_)
return {'diff': res, 'schedule': schedule}
def scheduler_update(scheduler, id_):
"""Update a scheduler job, using information from the JSON object
:param scheduler: the TornadoScheduler instance to modify
:type scheduler: TornadoScheduler
:param id_: ID of the schedule that must be updated
:type id_: str
:returns: True in case of success
:rtype: bool"""
schedule = get_schedule(id_, add_id=False)
if not schedule:
logger.warn('unable to update empty schedule %s' % id_)
return False
trigger = schedule.get('trigger')
if trigger not in ('interval', 'cron'):
logger.warn('unable to update empty schedule %s: trigger not in ("cron", "interval")' % id_)
return False
args = {}
if trigger == 'interval':
args['trigger'] = 'interval'
for unit in 'weeks', 'days', 'hours', 'minutes', 'seconds':
if 'interval_%s' % unit not in schedule:
continue
try:
val = schedule['interval_%s' % unit]
if not val:
continue
args[unit] = int(val)
except Exception:
logger.warn('invalid argument on schedule %s: %s parameter %s is not an integer' %
(id_, 'interval_%s' % unit, schedule['interval_%s' % unit]))
if len(args) == 1:
logger.error('no valid interval specified, skipping schedule %s' % id_)
return False
elif trigger == 'cron':
try:
cron_trigger = CronTrigger.from_crontab(schedule['cron_crontab'])
args['trigger'] = cron_trigger
except Exception:
logger.warn('invalid argument on schedule %s: cron_tab parameter %s is not a valid crontab' %
(id_, schedule.get('cron_crontab')))
return False
git_create_repo(id_)
try:
scheduler.add_job(safe_run_job, id=id_, replace_existing=True, kwargs={'id_': id_}, **args)
except Exception as e:
logger.warn('unable to update job %s: %s' % (id_, e))
return False
return True
def scheduler_delete(scheduler, id_):
"""Update a scheduler job, using information from the JSON object
:param scheduler: the TornadoScheduler instance to modify
:type scheduler: TornadoScheduler
:param id_: ID of the schedule
:type id_: str
:returns: True in case of success
:rtype: bool"""
try:
scheduler.remove_job(job_id=id_)
except Exception as e:
logger.warn('unable to delete job %s: %s' % (id_, e))
return False
return git_delete_repo(id_)
def reset_from_schedules(scheduler):
""""Reset all scheduler jobs, using information from the JSON object
:param scheduler: the TornadoScheduler instance to modify
:type scheduler: TornadoScheduler
:returns: True in case of success
:rtype: bool"""
ret = False
try:
scheduler.remove_all_jobs()
for key in read_schedules().get('schedules', {}).keys():
ret |= scheduler_update(scheduler, id_=key)
except Exception as e:
logger.warn('unable to reset all jobs: %s' % e)
return False
return ret
def git_init():
"""Initialize Git global settings"""
p = subprocess.Popen([GIT_CMD, 'config', '--global', 'user.email', '"%s"' % EMAIL_FROM])
p.communicate()
p = subprocess.Popen([GIT_CMD, 'config', '--global', 'user.name', '"Diffido"'])
p.communicate()
def git_create_repo(id_):
"""Create a Git repository
:param id_: ID of the schedule
:type id_: str
:returns: True in case of success
:rtype: bool"""
repo_dir = 'storage/%s' % id_
if os.path.isdir(repo_dir):
return True
p = subprocess.Popen([GIT_CMD, 'init', repo_dir])
p.communicate()
return p.returncode == 0
def git_delete_repo(id_):
"""Delete a Git repository
:param id_: ID of the schedule
:type id_: str
:returns: True in case of success
:rtype: bool"""
repo_dir = 'storage/%s' % id_
if not os.path.isdir(repo_dir):
return False
try:
shutil.rmtree(repo_dir)
except Exception as e:
logger.warn('unable to delete Git repository %s: %s' % (id_, e))
return False
return True
class DiffidoBaseException(Exception):
"""Base class for diffido custom exceptions.
:param message: text message
:type message: str
:param status: numeric http status code
:type status: int"""
def __init__(self, message, status=400):
super(DiffidoBaseException, self).__init__(message)
self.message = message
self.status = status
class BaseHandler(tornado.web.RequestHandler):
"""Base class for request handlers."""
# A property to access the first value of each argument.
arguments = property(lambda self: dict([(k, v[0].decode('utf-8'))
for k, v in self.request.arguments.items()]))
@property
def clean_body(self):
"""Return a clean dictionary from a JSON body, suitable for a query on MongoDB.
:returns: a clean copy of the body arguments
:rtype: dict"""
return escape.json_decode(self.request.body or '{}')
def write_error(self, status_code, **kwargs):
"""Default error handler."""
if isinstance(kwargs.get('exc_info', (None, None))[1], DiffidoBaseException):
exc = kwargs['exc_info'][1]
status_code = exc.status
message = exc.message
else:
message = 'internal error'
self.build_error(message, status=status_code)
def initialize(self, **kwargs):
"""Add every passed (key, value) as attributes of the instance."""
for key, value in kwargs.items():
setattr(self, key, value)
def build_error(self, message='', status=400):
"""Build and write an error message.
:param message: textual message
:type message: str
:param status: HTTP status code
:type status: int
"""
self.set_status(status)
self.write({'error': True, 'message': message})
def build_success(self, message='', status=200):
"""Build and write a success message.
:param message: textual message
:type message: str
:param status: HTTP status code
:type status: int
"""
self.set_status(status)
self.write({'error': False, 'message': message})
class SchedulesHandler(BaseHandler):
"""Schedules handler."""
@gen.coroutine
def get(self, id_=None, *args, **kwargs):
"""Get a schedule."""
if id_ is not None:
return self.write({'schedule': get_schedule(id_, add_history=True)})
schedules = read_schedules()
self.write(schedules)
@gen.coroutine
def put(self, id_=None, *args, **kwargs):
"""Update a schedule."""
if id_ is None:
return self.build_error(message='update action requires an ID')
data = self.clean_body
schedules = read_schedules()
if id_ not in schedules.get('schedules', {}):
return self.build_error(message='schedule %s not found' % id_)
schedules['schedules'][id_] = data
write_schedules(schedules)
scheduler_update(scheduler=self.scheduler, id_=id_)
self.write(get_schedule(id_=id_))
@gen.coroutine
def post(self, *args, **kwargs):
"""Add a schedule."""
data = self.clean_body
schedules = read_schedules()
id_ = next_id(schedules)
schedules['schedules'][id_] = data
write_schedules(schedules)
scheduler_update(scheduler=self.scheduler, id_=id_)
self.write(get_schedule(id_=id_))
@gen.coroutine
def delete(self, id_=None, *args, **kwargs):
"""Delete a schedule."""
if id_ is None:
return self.build_error(message='an ID must be specified')
schedules = read_schedules()
if id_ in schedules.get('schedules', {}):
del schedules['schedules'][id_]
write_schedules(schedules)
scheduler_delete(scheduler=self.scheduler, id_=id_)
self.build_success(message='removed schedule %s' % id_)
class RunScheduleHandler(BaseHandler):
"""Reset schedules handler."""
@gen.coroutine
def post(self, id_, *args, **kwargs):
if run_job(id_, force=True):
return self.build_success('job run')
self.build_error('job not run')
class ResetSchedulesHandler(BaseHandler):
"""Reset schedules handler."""
@gen.coroutine
def post(self, *args, **kwargs):
reset_from_schedules(self.scheduler)
class HistoryHandler(BaseHandler):
"""History handler."""
@gen.coroutine
def get(self, id_, *args, **kwargs):
self.write(get_history(id_, add_info=True))
class DiffHandler(BaseHandler):
"""Diff handler."""
@gen.coroutine
def get(self, id_, commit_id, old_commit_id=None, *args, **kwargs):
self.write(get_diff(id_, commit_id, old_commit_id))
class TemplateHandler(BaseHandler):
"""Handler for the template files in the / path."""
@gen.coroutine
def get(self, *args, **kwargs):
"""Get a template file."""
page = 'index.html'
if args and args[0]:
page = args[0].strip('/')
arguments = self.arguments
self.render(page, **arguments)
def serve():
"""Read configuration and start the server."""
global EMAIL_FROM, SMTP_SETTINGS
jobstores = {'default': SQLAlchemyJobStore(url=JOBS_STORE)}
scheduler = TornadoScheduler(jobstores=jobstores, timezone=pytz.utc)
scheduler.start()
define('port', default=3210, help='run on the given port', type=int)
define('address', default='', help='bind the server at the given address', type=str)
define('ssl_cert', default=os.path.join(os.path.dirname(__file__), 'ssl', 'diffido_cert.pem'),
help='specify the SSL certificate to use for secure connections')
define('ssl_key', default=os.path.join(os.path.dirname(__file__), 'ssl', 'diffido_key.pem'),
help='specify the SSL private key to use for secure connections')
define('admin-email', default='', help='email address of the site administrator', type=str)
define('smtp-host', default='localhost', help='SMTP server address', type=str)
define('smtp-port', default=0, help='SMTP server port', type=int)
define('smtp-local-hostname', default=None, help='SMTP local hostname', type=str)
define('smtp-use-ssl', default=False, help='Use SSL to connect to the SMTP server', type=bool)
define('smtp-starttls', default=False, help='Use STARTTLS to connect to the SMTP server', type=bool)
define('smtp-ssl-keyfile', default=None, help='SSL key file', type=str)
define('smtp-ssl-certfile', default=None, help='SSL cert file', type=str)
define('smtp-ssl-context', default=None, help='SSL context', type=str)
define('debug', default=False, help='run in debug mode', type=bool)
define('config', help='read configuration file',
callback=lambda path: tornado.options.parse_config_file(path, final=False))
if not options.config and os.path.isfile(DEFAULT_CONF):
tornado.options.parse_config_file(DEFAULT_CONF, final=False)
tornado.options.parse_command_line()
if options.admin_email:
EMAIL_FROM = options.admin_email
for key, value in options.as_dict().items():
if key.startswith('smtp-'):
SMTP_SETTINGS[key] = value
if options.debug:
logger.setLevel(logging.DEBUG)
ssl_options = {}
if os.path.isfile(options.ssl_key) and os.path.isfile(options.ssl_cert):
ssl_options = dict(certfile=options.ssl_cert, keyfile=options.ssl_key)
init_params = dict(listen_port=options.port, logger=logger, ssl_options=ssl_options,
scheduler=scheduler)
git_init()
_reset_schedules_path = r'schedules/reset'
_schedule_run_path = r'schedules/(?P<id_>\d+)/run'
_schedules_path = r'schedules/?(?P<id_>\d+)?'
_history_path = r'schedules/?(?P<id_>\d+)/history'
_diff_path = r'schedules/(?P<id_>\d+)/diff/(?P<commit_id>[0-9a-f]+)/?(?P<old_commit_id>[0-9a-f]+)?/?'
application = tornado.web.Application([
(r'/api/%s' % _reset_schedules_path, ResetSchedulesHandler, init_params),
(r'/api/v%s/%s' % (API_VERSION, _reset_schedules_path), ResetSchedulesHandler, init_params),
(r'/api/%s' % _schedule_run_path, RunScheduleHandler, init_params),
(r'/api/v%s/%s' % (API_VERSION, _schedule_run_path), RunScheduleHandler, init_params),
(r'/api/%s' % _history_path, HistoryHandler, init_params),
(r'/api/v%s/%s' % (API_VERSION, _history_path), HistoryHandler, init_params),
(r'/api/%s' % _diff_path, DiffHandler, init_params),
(r'/api/v%s/%s' % (API_VERSION, _diff_path), DiffHandler, init_params),
(r'/api/%s' % _schedules_path, SchedulesHandler, init_params),
(r'/api/v%s/%s' % (API_VERSION, _schedules_path), SchedulesHandler, init_params),
(r'/?(.*)', TemplateHandler, init_params),
],
static_path=os.path.join(os.path.dirname(__file__), 'dist/static'),
template_path=os.path.join(os.path.dirname(__file__), 'dist/'),
debug=options.debug)
http_server = tornado.httpserver.HTTPServer(application, ssl_options=ssl_options or None)
logger.info('Start serving on %s://%s:%d', 'https' if ssl_options else 'http',
options.address if options.address else '127.0.0.1',
options.port)
http_server.listen(options.port, options.address)
try:
IOLoop.instance().start()
except (KeyboardInterrupt, SystemExit):
pass
if __name__ == '__main__':
serve()