HTTP proxy handler.

The second of two new features to replace the _externals protocols. This
allows users to configure CouchDB to proxy requests to an external HTTP
server. The external HTTP server is not required to be on the same host
running CouchDB.

The configuration looks like such:

[httpd_global_handlers]
_google = {couch_httpd_proxy, handle_proxy_req, <<"http://www.google.com">>}

You can then hit this proxy at the url:

http://127.0.0.1:5984/_google

If you add any path after the proxy name, or make a request with a query
string, those will be appended to the URL specified in the configuration.

Ie:

    http://127.0.0.1:5984/_google/search?q=plankton

would translate to:

    http://www.google.com/search?q=plankton

Obviously, request bodies are handled as expected.



git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@1031877 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 99 insertions, 0 deletions

diff --git a/test/etap/test_web.erl b/test/etap/test_web.erl
new file mode 100644
index 00000000..16438b31
--- /dev/null
+++ b/test/etap/test_web.erl
@@ -0,0 +1,99 @@
+% 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.
+
+-module(test_web).
+-behaviour(gen_server).
+
+-export([start_link/0, loop/1, get_port/0, set_assert/1, check_last/0]).
+-export([init/1, terminate/2, code_change/3]).
+-export([handle_call/3, handle_cast/2, handle_info/2]).
+
+-define(SERVER, test_web_server).
+-define(HANDLER, test_web_handler).
+
+start_link() ->
+    gen_server:start({local, ?HANDLER}, ?MODULE, [], []),
+    mochiweb_http:start([
+        {name, ?SERVER},
+        {loop, {?MODULE, loop}},
+        {port, 5985}
+    ]).
+
+loop(Req) ->
+    %etap:diag("Handling request: ~p", [Req]),
+    case gen_server:call(?HANDLER, {check_request, Req}) of
+        {ok, RespInfo} ->
+            {ok, Req:respond(RespInfo)};
+        {raw, {Status, Headers, BodyChunks}} ->
+            Resp = Req:start_response({Status, Headers}),
+            lists:foreach(fun(C) -> Resp:send(C) end, BodyChunks),
+            erlang:put(mochiweb_request_force_close, true),
+            {ok, Resp};
+        {chunked, {Status, Headers, BodyChunks}} ->
+            Resp = Req:respond({Status, Headers, chunked}),
+            timer:sleep(500),
+            lists:foreach(fun(C) -> Resp:write_chunk(C) end, BodyChunks),
+            Resp:write_chunk([]),
+            {ok, Resp};
+        {error, Reason} ->
+            etap:diag("Error: ~p", [Reason]),
+            Body = lists:flatten(io_lib:format("Error: ~p", [Reason])),
+            {ok, Req:respond({200, [], Body})}
+    end.
+
+get_port() ->
+    mochiweb_socket_server:get(?SERVER, port).
+
+set_assert(Fun) ->
+    ok = gen_server:call(?HANDLER, {set_assert, Fun}).
+
+check_last() ->
+    gen_server:call(?HANDLER, last_status).
+
+init(_) ->
+    {ok, nil}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+handle_call({check_request, Req}, _From, State) when is_function(State, 1) ->
+    Resp2 = case (catch State(Req)) of
+        {ok, Resp} -> {reply, {ok, Resp}, was_ok};
+        {raw, Resp} -> {reply, {raw, Resp}, was_ok};
+        {chunked, Resp} -> {reply, {chunked, Resp}, was_ok};
+        Error -> {reply, {error, Error}, not_ok}
+    end,
+    Req:cleanup(),
+    Resp2;
+handle_call({check_request, _Req}, _From, _State) ->
+    {reply, {error, no_assert_function}, not_ok};
+handle_call(last_status, _From, State) when is_atom(State) ->
+    {reply, State, nil};
+handle_call(last_status, _From, State) ->
+    {reply, {error, not_checked}, State};
+handle_call({set_assert, Fun}, _From, nil) ->
+    {reply, ok, Fun};
+handle_call({set_assert, _}, _From, State) ->
+    {reply, {error, assert_function_set}, State};
+handle_call(Msg, _From, State) ->
+    {reply, {ignored, Msg}, State}.
+
+handle_cast(Msg, State) ->
+    etap:diag("Ignoring cast message: ~p", [Msg]),
+    {noreply, State}.
+
+handle_info(Msg, State) ->
+    etap:diag("Ignoring info message: ~p", [Msg]),
+    {noreply, State}.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.