exceptions: use only one exception handler to track errors with nicer

tracebacks.

vcsserver/http_main.py

@@ -1,424 +1,409 b''
 # RhodeCode VCSServer provides access to different vcs backends via network.
 # Copyright (C) 2014-2017 RodeCode GmbH
 #
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 # the Free Software Foundation; either version 3 of the License, or
 # (at your option) any later version.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software Foundation,
 # Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
 
 import base64
 import locale
 import logging
 import uuid
 import wsgiref.util
 import traceback
 from itertools import chain
 
 import msgpack
 from beaker.cache import CacheManager
 from beaker.util import parse_cache_config_options
 from pyramid.config import Configurator
 from pyramid.wsgi import wsgiapp
 
 from vcsserver import remote_wsgi, scm_app, settings, hgpatches
 from vcsserver.echo_stub import remote_wsgi as remote_wsgi_stub
 from vcsserver.echo_stub.echo_app import EchoApp
 from vcsserver.exceptions import HTTPRepoLocked
 from vcsserver.server import VcsServer
 
 try:
     from vcsserver.git import GitFactory, GitRemote
 except ImportError:
     GitFactory = None
     GitRemote = None
 try:
     from vcsserver.hg import MercurialFactory, HgRemote
 except ImportError:
     MercurialFactory = None
     HgRemote = None
 try:
     from vcsserver.svn import SubversionFactory, SvnRemote
 except ImportError:
     SubversionFactory = None
     SvnRemote = None
 
 log = logging.getLogger(__name__)
 
 
 class VCS(object):
     def __init__(self, locale=None, cache_config=None):
         self.locale = locale
         self.cache_config = cache_config
         self._configure_locale()
         self._initialize_cache()
 
         if GitFactory and GitRemote:
             git_repo_cache = self.cache.get_cache_region(
                 'git', region='repo_object')
             git_factory = GitFactory(git_repo_cache)
             self._git_remote = GitRemote(git_factory)
         else:
             log.info("Git client import failed")
 
         if MercurialFactory and HgRemote:
             hg_repo_cache = self.cache.get_cache_region(
                 'hg', region='repo_object')
             hg_factory = MercurialFactory(hg_repo_cache)
             self._hg_remote = HgRemote(hg_factory)
         else:
             log.info("Mercurial client import failed")
 
         if SubversionFactory and SvnRemote:
             svn_repo_cache = self.cache.get_cache_region(
                 'svn', region='repo_object')
             svn_factory = SubversionFactory(svn_repo_cache)
             self._svn_remote = SvnRemote(svn_factory, hg_factory=hg_factory)
         else:
             log.info("Subversion client import failed")
 
         self._vcsserver = VcsServer()
 
     def _initialize_cache(self):
         cache_config = parse_cache_config_options(self.cache_config)
         log.info('Initializing beaker cache: %s' % cache_config)
         self.cache = CacheManager(**cache_config)
 
     def _configure_locale(self):
         if self.locale:
             log.info('Settings locale: `LC_ALL` to %s' % self.locale)
         else:
             log.info(
                 'Configuring locale subsystem based on environment variables')
         try:
             # If self.locale is the empty string, then the locale
             # module will use the environment variables. See the
             # documentation of the package `locale`.
             locale.setlocale(locale.LC_ALL, self.locale)
 
             language_code, encoding = locale.getlocale()
             log.info(
                 'Locale set to language code "%s" with encoding "%s".',
                 language_code, encoding)
         except locale.Error:
             log.exception(
                 'Cannot set locale, not configuring the locale system')
 
 
 class WsgiProxy(object):
     def __init__(self, wsgi):
         self.wsgi = wsgi
 
     def __call__(self, environ, start_response):
         input_data = environ['wsgi.input'].read()
         input_data = msgpack.unpackb(input_data)
 
         error = None
         try:
             data, status, headers = self.wsgi.handle(
                 input_data['environment'], input_data['input_data'],
                 *input_data['args'], **input_data['kwargs'])
         except Exception as e:
             data, status, headers = [], None, None
             error = {
                 'message': str(e),
                 '_vcs_kind': getattr(e, '_vcs_kind', None)
             }
 
         start_response(200, {})
         return self._iterator(error, status, headers, data)
 
     def _iterator(self, error, status, headers, data):
         initial_data = [
             error,
             status,
             headers,
         ]
 
         for d in chain(initial_data, data):
             yield msgpack.packb(d)
 
 
 class HTTPApplication(object):
     ALLOWED_EXCEPTIONS = ('KeyError', 'URLError')
 
     remote_wsgi = remote_wsgi
     _use_echo_app = False
 
     def __init__(self, settings=None, global_config=None):
         self.config = Configurator(settings=settings)
         self.global_config = global_config
 
         locale = settings.get('locale', '') or 'en_US.UTF-8'
         vcs = VCS(locale=locale, cache_config=settings)
         self._remotes = {
             'hg': vcs._hg_remote,
             'git': vcs._git_remote,
             'svn': vcs._svn_remote,
             'server': vcs._vcsserver,
         }
         if settings.get('dev.use_echo_app', 'false').lower() == 'true':
             self._use_echo_app = True
             log.warning("Using EchoApp for VCS operations.")
             self.remote_wsgi = remote_wsgi_stub
         self._configure_settings(settings)
         self._configure()
 
     def _configure_settings(self, app_settings):
         """
         Configure the settings module.
         """
         git_path = app_settings.get('git_path', None)
         if git_path:
             settings.GIT_EXECUTABLE = git_path
 
     def _configure(self):
         self.config.add_renderer(
             name='msgpack',
             factory=self._msgpack_renderer_factory)
 
         self.config.add_route('service', '/_service')
         self.config.add_route('status', '/status')
         self.config.add_route('hg_proxy', '/proxy/hg')
         self.config.add_route('git_proxy', '/proxy/git')
         self.config.add_route('vcs', '/{backend}')
         self.config.add_route('stream_git', '/stream/git/*repo_name')
         self.config.add_route('stream_hg', '/stream/hg/*repo_name')
 
         self.config.add_view(
             self.status_view, route_name='status', renderer='json')
         self.config.add_view(
             self.service_view, route_name='service', renderer='msgpack')
 
         self.config.add_view(self.hg_proxy(), route_name='hg_proxy')
         self.config.add_view(self.git_proxy(), route_name='git_proxy')
         self.config.add_view(
             self.vcs_view, route_name='vcs', renderer='msgpack',
             custom_predicates=[self.is_vcs_view])
 
         self.config.add_view(self.hg_stream(), route_name='stream_hg')
         self.config.add_view(self.git_stream(), route_name='stream_git')
 
         def notfound(request):
             return {'status': '404 NOT FOUND'}
         self.config.add_notfound_view(notfound, renderer='json')
 
-        self.config.add_view(
-            self.handle_vcs_exception, context=Exception,
-            custom_predicates=[self.is_vcs_exception])
-
-        self.config.add_view(
-            self.general_error_handler, context=Exception)
+        self.config.add_view(self.handle_vcs_exception, context=Exception)
 
         self.config.add_tween(
             'vcsserver.tweens.RequestWrapperTween',
         )
 
     def wsgi_app(self):
         return self.config.make_wsgi_app()
 
     def vcs_view(self, request):
         remote = self._remotes[request.matchdict['backend']]
         payload = msgpack.unpackb(request.body, use_list=True)
         method = payload.get('method')
         params = payload.get('params')
         wire = params.get('wire')
         args = params.get('args')
         kwargs = params.get('kwargs')
         if wire:
             try:
                 wire['context'] = uuid.UUID(wire['context'])
             except KeyError:
                 pass
             args.insert(0, wire)
 
         log.debug('method called:%s with kwargs:%s', method, kwargs)
         try:
             resp = getattr(remote, method)(*args, **kwargs)
         except Exception as e:
             tb_info = traceback.format_exc()
 
             type_ = e.__class__.__name__
             if type_ not in self.ALLOWED_EXCEPTIONS:
                 type_ = None
 
             resp = {
                 'id': payload.get('id'),
                 'error': {
                     'message': e.message,
                     'traceback': tb_info,
                     'type': type_
                 }
             }
             try:
                 resp['error']['_vcs_kind'] = e._vcs_kind
             except AttributeError:
                 pass
         else:
             resp = {
                 'id': payload.get('id'),
                 'result': resp
             }
 
         return resp
 
     def status_view(self, request):
         return {'status': 'OK'}
 
     def service_view(self, request):
         import vcsserver
         import ConfigParser as configparser
 
         payload = msgpack.unpackb(request.body, use_list=True)
 
         try:
             path = self.global_config['__file__']
             config = configparser.ConfigParser()
             config.read(path)
             parsed_ini = config
             if parsed_ini.has_section('server:main'):
                 parsed_ini = dict(parsed_ini.items('server:main'))
         except Exception:
             log.exception('Failed to read .ini file for display')
             parsed_ini = {}
 
         resp = {
             'id': payload.get('id'),
             'result': dict(
                 version=vcsserver.__version__,
                 config=parsed_ini,
                 payload=payload,
             )
         }
         return resp
 
     def _msgpack_renderer_factory(self, info):
         def _render(value, system):
             value = msgpack.packb(value)
             request = system.get('request')
             if request is not None:
                 response = request.response
                 ct = response.content_type
                 if ct == response.default_content_type:
                     response.content_type = 'application/x-msgpack'
             return value
         return _render
 
     def hg_proxy(self):
         @wsgiapp
         def _hg_proxy(environ, start_response):
             app = WsgiProxy(self.remote_wsgi.HgRemoteWsgi())
             return app(environ, start_response)
         return _hg_proxy
 
     def git_proxy(self):
         @wsgiapp
         def _git_proxy(environ, start_response):
             app = WsgiProxy(self.remote_wsgi.GitRemoteWsgi())
             return app(environ, start_response)
         return _git_proxy
 
     def hg_stream(self):
         if self._use_echo_app:
             @wsgiapp
             def _hg_stream(environ, start_response):
                 app = EchoApp('fake_path', 'fake_name', None)
                 return app(environ, start_response)
             return _hg_stream
         else:
             @wsgiapp
             def _hg_stream(environ, start_response):
                 repo_path = environ['HTTP_X_RC_REPO_PATH']
                 repo_name = environ['HTTP_X_RC_REPO_NAME']
                 packed_config = base64.b64decode(
                     environ['HTTP_X_RC_REPO_CONFIG'])
                 config = msgpack.unpackb(packed_config)
                 app = scm_app.create_hg_wsgi_app(
                     repo_path, repo_name, config)
 
                 # Consitent path information for hgweb
                 environ['PATH_INFO'] = environ['HTTP_X_RC_PATH_INFO']
                 environ['REPO_NAME'] = repo_name
                 return app(environ, ResponseFilter(start_response))
             return _hg_stream
 
     def git_stream(self):
         if self._use_echo_app:
             @wsgiapp
             def _git_stream(environ, start_response):
                 app = EchoApp('fake_path', 'fake_name', None)
                 return app(environ, start_response)
             return _git_stream
         else:
             @wsgiapp
             def _git_stream(environ, start_response):
                 repo_path = environ['HTTP_X_RC_REPO_PATH']
                 repo_name = environ['HTTP_X_RC_REPO_NAME']
                 packed_config = base64.b64decode(
                     environ['HTTP_X_RC_REPO_CONFIG'])
                 config = msgpack.unpackb(packed_config)
 
                 environ['PATH_INFO'] = environ['HTTP_X_RC_PATH_INFO']
                 app = scm_app.create_git_wsgi_app(
                     repo_path, repo_name, config)
                 return app(environ, start_response)
             return _git_stream
 
     def is_vcs_view(self, context, request):
         """
         View predicate that returns true if given backend is supported by
         defined remotes.
         """
         backend = request.matchdict.get('backend')
         return backend in self._remotes
 
-    def is_vcs_exception(self, context, request):
-        """
-        View predicate that returns true if the context object is a VCS
-        exception.
-        """
-        return hasattr(context, '_vcs_kind')
-
     def handle_vcs_exception(self, exception, request):
-        if exception._vcs_kind == 'repo_locked':
+        _vcs_kind = getattr(exception, '_vcs_kind', '')
+        if _vcs_kind == 'repo_locked':
             # Get custom repo-locked status code if present.
             status_code = request.headers.get('X-RC-Locked-Status-Code')
             return HTTPRepoLocked(
                 title=exception.message, status_code=status_code)
 
         # Re-raise exception if we can not handle it.
-        raise exception
-
-    def general_error_handler(self, exception, request):
         log.exception(
-            'error occurred handling this request for path: %s',
-            request.path)
+            'error occurred handling this request for path: %s', request.path)
         raise exception
 
 
 class ResponseFilter(object):
 
     def __init__(self, start_response):
         self._start_response = start_response
 
     def __call__(self, status, response_headers, exc_info=None):
         headers = tuple(
             (h, v) for h, v in response_headers
             if not wsgiref.util.is_hop_by_hop(h))
         return self._start_response(status, headers, exc_info)
 
 
 def main(global_config, **settings):
     if MercurialFactory:
         hgpatches.patch_largefiles_capabilities()
         hgpatches.patch_subrepo_type_mapping()
     app = HTTPApplication(settings=settings, global_config=global_config)
     return app.wsgi_app()