zuul-storage-proxy/zuul_storage_proxy/__init__.py
James E. Blair 98e92bdd46 Switch to uwsgi
Use the opendev uwsgi base image.  A few additional changes are
needed beyond the container switch:

* WSGI protocol says headers must be a python list.  Uwsgi is very
  literal about that and does not permit an iterable, so we coerce
  items() to a list.
* Add the zuul_storage_proxy package to the setup.cfg files list so
  it gets installed.
* Remove a debug print.

Change-Id: I801d8b37699af8b937cc68d32f2a85c50eb91eb9
2021-02-11 15:54:54 -08:00

206 lines
5.9 KiB
Python

# Copyright 2020 BMW Group
#
# 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 logging
import openstack
import os
NOT_FOUND = b'''<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>404 Not Found</title>
</head><body>
<h1>Not Found</h1>
<p>The requested URL was not found on this server.</p>
</body></html>
'''
METHOD_NOT_ALLOWED = b'''<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>405 Method Not Allowed</title>
</head><body>
<h1>Method Not Allowed</h1>
<p>The requested method is not supported.</p>
</body></html>
'''
FORBIDDEN = b'''<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>403 Forbidden</title>
</head><body>
<h1>Forbidden</h1>
<p>Overwriting files is not allowed.</p>
</body></html>
'''
BACKEND_CONNECTION = b'''<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML 2.0//EN">
<html><head>
<title>503</title>
</head><body>
<h1>Backend problem</h1>
<p>Backend connection failed.</p>
</body></html>
'''
def redirect_directory(start_response, path):
# We need to redirect with the last element plus a terminating '/'
last_element = os.path.basename(path.rstrip('/'))
redirect = last_element + '/'
start_response(
'301 Moved Permanently',
[('Location', redirect)]
)
return iter([b''])
def data_generator(data):
chunk_size = 16384
buf = data.read(chunk_size)
while buf:
yield buf
buf = data.read(chunk_size)
def handle_get(start_response, clouds, container, path):
failures = []
for cloud in clouds:
with cloud.object_store.get(
'%s/%s' % (container, path),
stream=True) as response:
response_headers = {k: v for k, v in response.headers.items()}
if response.status_code == 404:
failures.append((404, ''))
continue
elif response.status_code != 200:
failures.append((response.status_code, response.reason))
continue
data = b'Status code %s' % str(response.status_code).encode()
start_response(
"{} {}".format(response.status_code, response.reason),
[('Content-Length', str(len(data)))]
)
yield data
return
if response_headers['Content-Type'] == 'application/directory':
# We got a directory so redirect it to path/index.html
return redirect_directory(start_response, path)
start_response(
"{} {}".format(response.status_code, response.reason),
list(response_headers.items()))
# We want to forward the compressed data stream here so use the raw
# response stream.
while response.raw:
data = response.raw.read(16384)
yield data
if len(data) == 0:
break
return
# When hitting a special failure in one cloud return this,
# otherwise return 404
for status_code, reason in failures:
if status_code == 404:
# handle later
continue
# We hit a special failure, report this
data = b'Status code %s' % str(status_code).encode()
start_response(
"{} {}".format(status_code, reason),
[('Content-Length', str(len(data)))]
)
yield data
return
# No special failure, return 404
start_response(
'404 Not Found', []
)
yield NOT_FOUND
return
def swift_proxy(environ, start_response, clouds, container_prefix):
path = environ['PATH_INFO'].lstrip('/')
method = environ['REQUEST_METHOD']
# If the path ends with a / this is a directory and we want to deliver the
# index.html instead.
if path.endswith('/'):
path += 'index.html'
components = path.split('/', 1)
if not path:
start_response(
'404 Not Found', []
)
yield NOT_FOUND
return
if len(components) < 2:
# no container or path given, redirect to root index
return redirect_directory(start_response, path)
container = components[0]
path = components[1]
container = container_prefix + container
try:
if method == 'GET':
for chunk in handle_get(start_response, clouds, container, path):
yield chunk
else:
start_response(
'405 Method Not Allowed', []
)
yield METHOD_NOT_ALLOWED
except Exception as e:
start_response(
'503 Backend connection failed', []
)
yield '{}\n'.format(e).encode()
class CloudCache(object):
def __init__(self, app):
self.log = logging.getLogger('middleware')
self.app = app
cloud_names = os.environ['CLOUD_NAMES'].split(',')
self.clouds = []
for cloud_name in cloud_names:
self.log.info('Using cloud %s', cloud_name)
self.clouds.append(openstack.connect(cloud=cloud_name))
self.container_prefix = os.environ.get('CONTAINER_PREFIX', '')
if self.container_prefix:
self.log.info('Using container prefix %s',
self.container_prefix)
def __call__(self, environ, start_response):
for chunk in self.app(environ, start_response, self.clouds,
self.container_prefix):
yield chunk
proxy = CloudCache(swift_proxy)