[erp5_http_proxy] Prototype of an usable HTTP proxy.

It can be used with an external method by providing the URL to proxy as a query parameter:
ERP5Site_getHTTPResource?url=URL

The query is synchronous (no portal_activities), so, the Zope thread will be blocked until the external request is other.
In order to prevent consuming all threads, there is a really aggressive timeout of 1 second only.
This is enough for a RSS reader.
If the timeout is to short, do not increase it, but change the proxy design to use portal_activities instead.

For now, only authenticated user can use it (to prevent becoming an open proxy).
Only GET query are allowed (until a use case required any other HTTP method).

bt5/erp5_http_proxy/ExtensionTemplateItem/portal_components/extension.erp5.HTTPProxy.py

+import requests
+
+# Extremely aggressive and hardcoded value
+TIMEOUT = 1
+
+def request(self, url, REQUEST):
+  RESPONSE = REQUEST.RESPONSE
+
+  portal = self.getPortalObject()
+  if (portal.portal_membership.isAnonymousUser()):
+    RESPONSE.setStatus(403)
+    return ""
+  elif REQUEST.other['method'] != "GET":
+    RESPONSE.setStatus(405)
+    return ""
+
+  proxy_query_header = {}
+  for k in ["Content-Type", "Accept", "Accept-Language", "Range",
+            "If-Modified-Since", "If-None-Match"]:
+    v = REQUEST.getHeader(k, None)
+    if v is not None:
+      proxy_query_header[k] = v
+
+  try:
+    proxy_response = requests.request(
+      REQUEST.other['method'],
+      url,
+      # Propage the HTTP body (for POST)
+      data=REQUEST.get('BODY'),
+      # Propagate to headers to use HTTP cache as much as possible
+      headers=proxy_query_header,
+      # Do not block ERP5 if queried server is too slow
+      timeout=TIMEOUT
+    )
+  except requests.exceptions.SSLError:
+    # Invalid SSL Certificate
+    status_code = 526
+  except requests.exceptions.ConnectionError:
+    status_code = 523
+  except requests.exceptions.Timeout:
+    status_code = 524
+  except requests.exceptions.TooManyRedirects:
+    status_code = 520
+  else:
+    status_code = proxy_response.status_code
+    if status_code == 500:
+      status_code = 520
+
+    for k, v in proxy_response.headers.items():
+      k = k.title()
+      if k in ["Content-Disposition", "Content-Type", "Date", "Last-Modified",
+               "Vary", "Cache-Control", "Etag", "Accept-Ranges",
+               "Content-Range"]:
+        RESPONSE.setHeader(k, v)
+      """
+      elif k == "Location":
+        # In case of redirect, allow to directly fetch from proxy
+      """
+
+  RESPONSE.setStatus(status_code)
+  return proxy_response.content
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bt5/erp5_http_proxy/ExtensionTemplateItem/portal_components/extension.erp5.HTTPProxy.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="Extension Component" module="erp5.portal_type"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>_recorded_property_dict</string> </key>
+            <value>
+              <persistent> <string encoding="base64">AAAAAAAAAAI=</string> </persistent>
+            </value>
+        </item>
+        <item>
+            <key> <string>default_reference</string> </key>
+            <value> <string>HTTPProxy</string> </value>
+        </item>
+        <item>
+            <key> <string>description</string> </key>
+            <value>
+              <none/>
+            </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>extension.erp5.HTTPProxy</string> </value>
+        </item>
+        <item>
+            <key> <string>portal_type</string> </key>
+            <value> <string>Extension Component</string> </value>
+        </item>
+        <item>
+            <key> <string>sid</string> </key>
+            <value>
+              <none/>
+            </value>
+        </item>
+        <item>
+            <key> <string>text_content_error_message</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
+        <item>
+            <key> <string>text_content_warning_message</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
+        <item>
+            <key> <string>version</string> </key>
+            <value> <string>erp5</string> </value>
+        </item>
+        <item>
+            <key> <string>workflow_history</string> </key>
+            <value>
+              <persistent> <string encoding="base64">AAAAAAAAAAM=</string> </persistent>
+            </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+  <record id="2" aka="AAAAAAAAAAI=">
+    <pickle>
+      <global name="PersistentMapping" module="Persistence.mapping"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>data</string> </key>
+            <value>
+              <dictionary/>
+            </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+  <record id="3" aka="AAAAAAAAAAM=">
+    <pickle>
+      <global name="PersistentMapping" module="Persistence.mapping"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>data</string> </key>
+            <value>
+              <dictionary>
+                <item>
+                    <key> <string>component_validation_workflow</string> </key>
+                    <value>
+                      <persistent> <string encoding="base64">AAAAAAAAAAQ=</string> </persistent>
+                    </value>
+                </item>
+              </dictionary>
+            </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+  <record id="4" aka="AAAAAAAAAAQ=">
+    <pickle>
+      <global name="WorkflowHistoryList" module="Products.ERP5Type.patches.WorkflowTool"/>
+    </pickle>
+    <pickle>
+      <tuple>
+        <none/>
+        <list>
+          <dictionary>
+            <item>
+                <key> <string>action</string> </key>
+                <value> <string>validate</string> </value>
+            </item>
+            <item>
+                <key> <string>validation_state</string> </key>
+                <value> <string>validated</string> </value>
+            </item>
+          </dictionary>
+        </list>
+      </tuple>
+    </pickle>
+  </record>
+</ZopeData>

bt5/erp5_http_proxy/SkinTemplateItem/portal_skins/erp5_http_proxy.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="Folder" module="OFS.Folder"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>_objects</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>erp5_http_proxy</string> </value>
+        </item>
+        <item>
+            <key> <string>title</string> </key>
+            <value> <string></string> </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+</ZopeData>

bt5/erp5_http_proxy/SkinTemplateItem/portal_skins/erp5_http_proxy/ERP5Site_getHTTPResource.xml

+<?xml version="1.0"?>
+<ZopeData>
+  <record id="1" aka="AAAAAAAAAAE=">
+    <pickle>
+      <global name="ExternalMethod" module="Products.ExternalMethod.ExternalMethod"/>
+    </pickle>
+    <pickle>
+      <dictionary>
+        <item>
+            <key> <string>_function</string> </key>
+            <value> <string>request</string> </value>
+        </item>
+        <item>
+            <key> <string>_module</string> </key>
+            <value> <string>HTTPProxy</string> </value>
+        </item>
+        <item>
+            <key> <string>id</string> </key>
+            <value> <string>ERP5Site_getHTTPResource</string> </value>
+        </item>
+        <item>
+            <key> <string>title</string> </key>
+            <value> <string></string> </value>
+        </item>
+      </dictionary>
+    </pickle>
+  </record>
+</ZopeData>

bt5/erp5_http_proxy/bt/description

+Provides an HTTP Proxy to bypass the browser cross domain protection.
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bt5/erp5_http_proxy/bt/license

+GPL
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bt5/erp5_http_proxy/bt/template_extension_id_list

+extension.erp5.HTTPProxy
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bt5/erp5_http_proxy/bt/template_format_version

+1
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bt5/erp5_http_proxy/bt/template_skin_id_list

+erp5_http_proxy
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bt5/erp5_http_proxy/bt/title

+erp5_http_proxy
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bt5/erp5_http_proxy/bt/version

+001
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