snf-django-lib: provide proxy functionality

snf-django-lib/snf_django/lib/api/proxy/__init__.py

+# Copyright 2012, 2013 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+#
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+#
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+
+from django.http import HttpResponse
+
+from synnefo.lib.pool.http import PooledHTTPConnection
+
+from .utils import fix_header, forward_header
+
+import urllib
+import urlparse
+
+
+def proxy(request, target):
+    kwargs = {}
+
+    # prepare headers
+    headers = dict(map(lambda (k, v): fix_header(k, v),
+                   filter(lambda (k, v): forward_header(k),
+                          request.META.iteritems())))
+
+    kwargs['headers'] = headers
+    kwargs['body'] = request.raw_post_data
+
+    p = urlparse.urlparse(target)
+    with PooledHTTPConnection(p.netloc, p.scheme) as conn:
+        conn.request(
+            request.method,
+            '?'.join([request.path, urllib.urlencode(request.GET)]),
+            **kwargs)
+        response = conn.getresponse()
+
+        # turn httplib.HttpResponse to django.http.Response
+        length = response.getheader('content-length', None)
+        data = response.read(length)
+        status = int(response.status)
+        return HttpResponse(data, status=status)

snf-django-lib/snf_django/lib/api/proxy/utils.py

+# Copyright 2012, 2013 GRNET S.A. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or
+# without modification, are permitted provided that the following
+# conditions are met:
+#
+#   1. Redistributions of source code must retain the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer.
+#
+#   2. Redistributions in binary form must reproduce the above
+#      copyright notice, this list of conditions and the following
+#      disclaimer in the documentation and/or other materials
+#      provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS
+# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR
+# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+# The views and conclusions contained in the software and
+# documentation are those of the authors and should not be
+# interpreted as representing official policies, either expressed
+# or implied, of GRNET S.A.
+
+from django.core.servers.basehttp import is_hop_by_hop
+
+
+def fix_header(k, v):
+    prefix = 'HTTP_'
+    if k.startswith(prefix):
+        k = k[len(prefix):].title().replace('_', '-')
+    elif k in ('CONTENT_TYPE', 'CONTENT_LENGTH'):
+        k = k.replace('_', '-')
+    return k, v
+
+
+def forward_header(k):
+    return k.lower() != "HOST" and not is_hop_by_hop(k)