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% 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(couch_httpd_external).
-export([handle_external_req/2, handle_external_req/3]).
-export([send_external_response/2, json_req_obj/2]).
-export([default_or_content_type/2, parse_external_response/1]).
-import(couch_httpd,[send_error/4]).
-include("couch_db.hrl").
% handle_external_req/2
% for the old type of config usage:
% _external = {couch_httpd_external, handle_external_req}
% with urls like
% /db/_external/action/design/name
handle_external_req(#httpd{
path_parts=[_DbName, _External, UrlName | _Path]
}=HttpReq, Db) ->
process_external_req(HttpReq, Db, UrlName);
handle_external_req(#httpd{path_parts=[_, _]}=Req, _Db) ->
send_error(Req, 404, <<"external_server_error">>, <<"No server name specified.">>);
handle_external_req(Req, _) ->
send_error(Req, 404, <<"external_server_error">>, <<"Broken assumption">>).
% handle_external_req/3
% for this type of config usage:
% _action = {couch_httpd_external, handle_external_req, <<"action">>}
% with urls like
% /db/_action/design/name
handle_external_req(HttpReq, Db, Name) ->
process_external_req(HttpReq, Db, Name).
process_external_req(HttpReq, Db, Name) ->
Response = couch_external_manager:execute(binary_to_list(Name),
json_req_obj(HttpReq, Db)),
case Response of
{unknown_external_server, Msg} ->
send_error(HttpReq, 404, <<"external_server_error">>, Msg);
_ ->
send_external_response(HttpReq, Response)
end.
json_req_obj(#httpd{mochi_req=Req,
method=Verb,
path_parts=Path,
req_body=ReqBody,
user_ctx=#user_ctx{name=UserName, roles=UserRoles}
}, Db) ->
Body = case ReqBody of
undefined -> Req:recv_body();
Else -> Else
end,
ParsedForm = case Req:get_primary_header_value("content-type") of
"application/x-www-form-urlencoded" ++ _ ->
mochiweb_util:parse_qs(Body);
_ ->
[]
end,
UserCtx = {[{<<"name">>, UserName}, {<<"roles">>, UserRoles}]},
Headers = Req:get(headers),
Hlist = mochiweb_headers:to_list(Headers),
{ok, Info} = couch_db:get_db_info(Db),
% add headers...
{[{<<"info">>, {Info}},
{<<"verb">>, Verb},
{<<"path">>, Path},
{<<"query">>, to_json_terms(Req:parse_qs())},
{<<"headers">>, to_json_terms(Hlist)},
{<<"body">>, Body},
{<<"form">>, to_json_terms(ParsedForm)},
{<<"cookie">>, to_json_terms(Req:parse_cookie())},
{<<"userCtx">>, UserCtx}]}.
to_json_terms(Data) ->
to_json_terms(Data, []).
to_json_terms([], Acc) ->
{lists:reverse(Acc)};
to_json_terms([{Key, Value} | Rest], Acc) when is_atom(Key) ->
to_json_terms(Rest, [{list_to_binary(atom_to_list(Key)), list_to_binary(Value)} | Acc]);
to_json_terms([{Key, Value} | Rest], Acc) ->
to_json_terms(Rest, [{list_to_binary(Key), list_to_binary(Value)} | Acc]).
send_external_response(#httpd{mochi_req=MochiReq}, Response) ->
#extern_resp_args{
code = Code,
data = Data,
ctype = CType,
headers = Headers
} = parse_external_response(Response),
Resp = MochiReq:respond({Code,
default_or_content_type(CType, Headers ++ couch_httpd:server_header()), Data}),
{ok, Resp}.
parse_external_response({Response}) ->
lists:foldl(fun({Key,Value}, Args) ->
case {Key, Value} of
{"", _} ->
Args;
{<<"code">>, Value} ->
Args#extern_resp_args{code=Value};
{<<"stop">>, true} ->
Args#extern_resp_args{stop=true};
{<<"json">>, Value} ->
Args#extern_resp_args{
data=?JSON_ENCODE(Value),
ctype="application/json"};
{<<"body">>, Value} ->
Args#extern_resp_args{data=Value, ctype="text/html; charset=utf-8"};
{<<"base64">>, Value} ->
Args#extern_resp_args{
data=couch_util:decodeBase64(Value),
ctype="application/binary"
};
{<<"headers">>, {Headers}} ->
NewHeaders = lists:map(fun({Header, HVal}) ->
{binary_to_list(Header), binary_to_list(HVal)}
end, Headers),
Args#extern_resp_args{headers=NewHeaders};
_ -> % unknown key
Msg = lists:flatten(io_lib:format("Invalid data from external server: ~p", [{Key, Value}])),
throw({external_response_error, Msg})
end
end, #extern_resp_args{}, Response).
default_or_content_type(DefaultContentType, Headers) ->
{ContentType, OtherHeaders} = lists:partition(
fun({HeaderName, _}) ->
HeaderName == "Content-Type"
end, Headers),
% XXX: What happens if we were passed multiple content types? We add another?
case ContentType of
[{"Content-Type", SetContentType}] ->
TrueContentType = SetContentType;
_Else ->
TrueContentType = DefaultContentType
end,
HeadersWithContentType = lists:append(OtherHeaders, [{"Content-Type", TrueContentType}]),
HeadersWithContentType.
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