config: abort early if the environment doesn't allow Python to pass Unicode strings to the file system layer

Dulwich passes unicode paths to the file system layer and it will thus not work
if run with LC_ALL=C ... which is quite common for services.

Also try to detect different cases and give helpful error messages about what
environment variable could be changed to what.

kallithea/config/app_cfg.py

@@ -1,198 +1,214 b''
 # -*- coding: utf-8 -*-
 # 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, see <http://www.gnu.org/licenses/>.
 """
 Global configuration file for TurboGears2 specific settings in Kallithea.
 
 This file complements the .ini file.
 """
 
 import platform
 import os, sys, logging
 
 import tg
 from tg import hooks
 from tg.configuration import AppConfig
 from tg.support.converters import asbool
 import alembic.config
 from alembic.script.base import ScriptDirectory
 from alembic.migration import MigrationContext
 from sqlalchemy import create_engine
 import mercurial
 
 from kallithea.lib.middleware.https_fixup import HttpsFixup
 from kallithea.lib.middleware.simplegit import SimpleGit
 from kallithea.lib.middleware.simplehg import SimpleHg
 from kallithea.lib.auth import set_available_permissions
 from kallithea.lib.utils import load_rcextensions, make_ui, set_app_settings, set_vcs_config, \
     set_indexer_config, check_git_version, repo2db_mapper
 from kallithea.lib.utils2 import str2bool
 import kallithea.model.base
 from kallithea.model.scm import ScmModel
 
 import formencode
 
 log = logging.getLogger(__name__)
 
 
 class KallitheaAppConfig(AppConfig):
     # Note: AppConfig has a misleading name, as it's not the application
     # configuration, but the application configurator. The AppConfig values are
     # used as a template to create the actual configuration, which might
     # overwrite or extend the one provided by the configurator template.
 
     # To make it clear, AppConfig creates the config and sets into it the same
     # values that AppConfig itself has. Then the values from the config file and
     # gearbox options are loaded and merged into the configuration. Then an
     # after_init_config(conf) method of AppConfig is called for any change that
     # might depend on options provided by configuration files.
 
     def __init__(self):
         super(KallitheaAppConfig, self).__init__()
 
         self['package'] = kallithea
 
         self['prefer_toscawidgets2'] = False
         self['use_toscawidgets'] = False
 
         self['renderers'] = []
 
         # Enable json in expose
         self['renderers'].append('json')
 
         # Configure template rendering
         self['renderers'].append('mako')
         self['default_renderer'] = 'mako'
         self['use_dotted_templatenames'] = False
 
         # Configure Sessions, store data as JSON to avoid pickle security issues
         self['session.enabled'] = True
         self['session.data_serializer'] = 'json'
 
         # Configure the base SQLALchemy Setup
         self['use_sqlalchemy'] = True
         self['model'] = kallithea.model.base
         self['DBSession'] = kallithea.model.meta.Session
 
         # Configure App without an authentication backend.
         self['auth_backend'] = None
 
         # Use custom error page for these errors. By default, Turbogears2 does not add
         # 400 in this list.
         # Explicitly listing all is considered more robust than appending to defaults,
         # in light of possible future framework changes.
         self['errorpage.status_codes'] = [400, 401, 403, 404]
 
         # Disable transaction manager -- currently Kallithea takes care of transactions itself
         self['tm.enabled'] = False
 
 
 base_config = KallitheaAppConfig()
 
 # TODO still needed as long as we use pylonslib
 sys.modules['pylons'] = tg
 
 # DebugBar, a debug toolbar for TurboGears2.
 # (https://github.com/TurboGears/tgext.debugbar)
 # To enable it, install 'tgext.debugbar' and 'kajiki', and run Kallithea with
 # 'debug = true' (not in production!)
 # See the Kallithea documentation for more information.
 try:
     from tgext.debugbar import enable_debugbar
     import kajiki # only to check its existence
 except ImportError:
     pass
 else:
     base_config['renderers'].append('kajiki')
     enable_debugbar(base_config)
 
 
 def setup_configuration(app):
     config = app.config
 
+    # Verify that things work when Dulwich passes unicode paths to the file system layer.
+    # Note: UTF-8 is preferred, but for example ISO-8859-1 or mbcs should also work under the right cirumstances.
+    try:
+        u'\xe9'.encode(sys.getfilesystemencoding()) # Test using é (&eacute;)
+    except UnicodeEncodeError:
+        log.error("Cannot encode Unicode paths to file system encoding %r", sys.getfilesystemencoding())
+        for var in ['LC_CTYPE', 'LC_ALL', 'LANG']:
+            if var in os.environ:
+                val = os.environ[var]
+                log.error("Note: Environment variable %s is %r - perhaps change it to some other value from 'locale -a', like 'C.UTF-8' or 'en_US.UTF-8'", var, val)
+                break
+        else:
+            log.error("Note: No locale setting found in environment variables - perhaps set LC_CTYPE to some value from 'locale -a', like 'C.UTF-8' or 'en_US.UTF-8'")
+        log.error("Terminating ...")
+        sys.exit(1)
+
     # Mercurial sets encoding at module import time, so we have to monkey patch it
     hgencoding = config.get('hgencoding')
     if hgencoding:
         mercurial.encoding.encoding = hgencoding
 
     if config.get('ignore_alembic_revision', False):
         log.warn('database alembic revision checking is disabled')
     else:
         dbconf = config['sqlalchemy.url']
         alembic_cfg = alembic.config.Config()
         alembic_cfg.set_main_option('script_location', 'kallithea:alembic')
         alembic_cfg.set_main_option('sqlalchemy.url', dbconf)
         script_dir = ScriptDirectory.from_config(alembic_cfg)
         available_heads = sorted(script_dir.get_heads())
 
         engine = create_engine(dbconf)
         with engine.connect() as conn:
             context = MigrationContext.configure(conn)
             current_heads = sorted(str(s) for s in context.get_current_heads())
         if current_heads != available_heads:
             log.error('Failed to run Kallithea:\n\n'
                       'The database version does not match the Kallithea version.\n'
                       'Please read the documentation on how to upgrade or downgrade the database.\n'
                       'Current database version id(s): %s\n'
                       'Expected database version id(s): %s\n'
                       'If you are a developer and you know what you are doing, you can add `ignore_alembic_revision = True` '
                       'to your .ini file to skip the check.\n' % (' '.join(current_heads), ' '.join(available_heads)))
             sys.exit(1)
 
     # store some globals into kallithea
     kallithea.CELERY_ON = str2bool(config['app_conf'].get('use_celery'))
     kallithea.CELERY_EAGER = str2bool(config['app_conf'].get('celery.always.eager'))
     kallithea.CONFIG = config
 
     load_rcextensions(root_path=config['here'])
 
     set_available_permissions(config)
     repos_path = make_ui('db').configitems('paths')[0][1]
     config['base_path'] = repos_path
     set_app_settings(config)
 
     instance_id = kallithea.CONFIG.get('instance_id', '*')
     if instance_id == '*':
         instance_id = '%s-%s' % (platform.uname()[1], os.getpid())
         kallithea.CONFIG['instance_id'] = instance_id
 
     # update kallithea.CONFIG with the meanwhile changed 'config'
     kallithea.CONFIG.update(config)
 
     # configure vcs and indexer libraries (they are supposed to be independent
     # as much as possible and thus avoid importing tg.config or
     # kallithea.CONFIG).
     set_vcs_config(kallithea.CONFIG)
     set_indexer_config(kallithea.CONFIG)
 
     check_git_version()
 
 
 hooks.register('configure_new_app', setup_configuration)
 
 
 def setup_application(app):
     config = app.config
 
     # we want our low level middleware to get to the request ASAP. We don't
     # need any stack middleware in them - especially no StatusCodeRedirect buffering
     app = SimpleHg(app, config)
     app = SimpleGit(app, config)
 
     # Enable https redirects based on HTTP_X_URL_SCHEME set by proxy
     if any(asbool(config.get(x)) for x in ['https_fixup', 'force_https', 'use_htsts']):
         app = HttpsFixup(app, config)
     return app
 
 
 hooks.register('before_config', setup_application)