vcsserver/http_main.py

# RhodeCode VCSServer provides access to different vcs backends via network.
# Copyright (C) 2014-2018 RhodeCode 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 os
import base64
import locale
import logging
import uuid
import wsgiref.util
import traceback
from itertools import chain

import simplejson as json
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.git_lfs.app import GIT_LFS_CONTENT_TYPE, GIT_LFS_PROTO_PAT
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__)


def _is_request_chunked(environ):
    stream = environ.get('HTTP_TRANSFER_ENCODING', '') == 'chunked'
    return stream


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)

        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):
        import vcsserver
        return {'status': 'OK', 'vcsserver_version': vcsserver.__version__,
                'pid': os.getpid()}

    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 set_env_from_config(self, environ, config):
        dict_conf = {}
        try:
            for elem in config:
                if elem[0] == 'rhodecode':
                    dict_conf = json.loads(elem[2])
                    break
        except Exception:
            log.exception('Failed to fetch SCM CONFIG')
            return

        username = dict_conf.get('username')
        if username:
            environ['REMOTE_USER'] = username
            # mercurial specific, some extension api rely on this
            environ['HGUSER'] = username

        ip = dict_conf.get('ip')
        if ip:
            environ['REMOTE_HOST'] = ip

        if _is_request_chunked(environ):
            # set the compatibility flag for webob
            environ['wsgi.input_terminated'] = True

    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):
                log.debug('http-app: handling hg stream')
                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)

                # Consistent path information for hgweb
                environ['PATH_INFO'] = environ['HTTP_X_RC_PATH_INFO']
                environ['REPO_NAME'] = repo_name
                self.set_env_from_config(environ, config)

                log.debug('http-app: starting app handler '
                          'with %s and process request', app)
                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):
                log.debug('http-app: handling git stream')
                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']
                self.set_env_from_config(environ, config)

                content_type = environ.get('CONTENT_TYPE', '')

                path = environ['PATH_INFO']
                is_lfs_request = GIT_LFS_CONTENT_TYPE in content_type
                log.debug(
                    'LFS: Detecting if request `%s` is LFS server path based '
                    'on content type:`%s`, is_lfs:%s',
                    path, content_type, is_lfs_request)

                if not is_lfs_request:
                    # fallback detection by path
                    if GIT_LFS_PROTO_PAT.match(path):
                        is_lfs_request = True
                    log.debug(
                        'LFS: fallback detection by path of: `%s`, is_lfs:%s',
                        path, is_lfs_request)

                if is_lfs_request:
                    app = scm_app.create_git_lfs_wsgi_app(
                        repo_path, repo_name, config)
                else:
                    app = scm_app.create_git_wsgi_app(
                        repo_path, repo_name, config)

                log.debug('http-app: starting app handler '
                          'with %s and process request', app)

                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 handle_vcs_exception(self, exception, request):
        _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.
        log.exception(
            '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()