%%%----------------------------------------------------------------------
%%% File : rest.erl
%%% Author : Christophe Romain <christophe.romain@process-one.net>
%%% Purpose : Generic REST client
%%% Created : 16 Oct 2014 by Christophe Romain <christophe.romain@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2020 ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 of the
%%% License, or (at your option) any later version.
%%%
%%% This program is distributed in the hope that it will be useful,
%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License along
%%% with this program; if not, write to the Free Software Foundation, Inc.,
%%% 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
%%%
%%%----------------------------------------------------------------------
-module(rest).
-export([start/1, stop/1, get/2, get/3, post/4, delete/2,
put/4, patch/4, request/6, with_retry/4,
encode_json/1]).
-include("logger.hrl").
-define(HTTP_TIMEOUT, 10000).
-define(CONNECT_TIMEOUT, 8000).
-define(CONTENT_TYPE, "application/json").
start(Host) ->
application:start(inets),
Size = ejabberd_option:ext_api_http_pool_size(Host),
httpc:set_options([{max_sessions, Size}]).
stop(_Host) ->
ok.
with_retry(Method, Args, MaxRetries, Backoff) ->
with_retry(Method, Args, 0, MaxRetries, Backoff).
with_retry(Method, Args, Retries, MaxRetries, Backoff) ->
case apply(?MODULE, Method, Args) of
%% Only retry on timeout errors
{error, {http_error,{error,Error}}}
when Retries < MaxRetries
andalso (Error == 'timeout' orelse Error == 'connect_timeout') ->
timer:sleep(round(math:pow(2, Retries)) * Backoff),
with_retry(Method, Args, Retries+1, MaxRetries, Backoff);
Result ->
Result
end.
get(Server, Path) ->
request(Server, get, Path, [], ?CONTENT_TYPE, <<>>).
get(Server, Path, Params) ->
request(Server, get, Path, Params, ?CONTENT_TYPE, <<>>).
delete(Server, Path) ->
request(Server, delete, Path, [], ?CONTENT_TYPE, <<>>).
post(Server, Path, Params, Content) ->
Data = encode_json(Content),
request(Server, post, Path, Params, ?CONTENT_TYPE, Data).
put(Server, Path, Params, Content) ->
Data = encode_json(Content),
request(Server, put, Path, Params, ?CONTENT_TYPE, Data).
patch(Server, Path, Params, Content) ->
Data = encode_json(Content),
request(Server, patch, Path, Params, ?CONTENT_TYPE, Data).
request(Server, Method, Path, _Params, _Mime, {error, Error}) ->
ejabberd_hooks:run(backend_api_error, Server,
[Server, Method, Path, Error]),
{error, Error};
request(Server, Method, Path, Params, Mime, Data) ->
{Query, Opts} = case Params of
{_, _} -> Params;
_ -> {Params, []}
end,
URI = to_list(url(Server, Path, Query)),
HttpOpts = [{connect_timeout, ?CONNECT_TIMEOUT},
{timeout, ?HTTP_TIMEOUT}],
Hdrs = [{"connection", "keep-alive"},
{"Accept", "application/json"},
{"User-Agent", "ejabberd"}]
++ custom_headers(Server),
Req = if
(Method =:= post) orelse (Method =:= patch) orelse (Method =:= put) orelse (Method =:= delete) ->
{URI, Hdrs, to_list(Mime), Data};
true ->
{URI, Hdrs}
end,
Begin = os:timestamp(),
ejabberd_hooks:run(backend_api_call, Server, [Server, Method, Path]),
Result = try httpc:request(Method, Req, HttpOpts, [{body_format, binary}]) of
{ok, {{_, Code, _}, RetHdrs, Body}} ->
try decode_json(Body) of
JSon ->
case proplists:get_bool(return_headers, Opts) of
true -> {ok, Code, RetHdrs, JSon};
false -> {ok, Code, JSon}
end
catch
_:Reason ->
{error, {invalid_json, Body, Reason}}
end;
{error, Reason} ->
{error, {http_error, {error, Reason}}}
catch
exit:Reason ->
{error, {http_error, {error, Reason}}}
end,
case Result of
{error, {http_error, {error, timeout}}} ->
ejabberd_hooks:run(backend_api_timeout, Server,
[Server, Method, Path]);
{error, {http_error, {error, connect_timeout}}} ->
ejabberd_hooks:run(backend_api_timeout, Server,
[Server, Method, Path]);
{error, Error} ->
ejabberd_hooks:run(backend_api_error, Server,
[Server, Method, Path, Error]);
_ ->
End = os:timestamp(),
Elapsed = timer:now_diff(End, Begin) div 1000, %% time in ms
ejabberd_hooks:run(backend_api_response_time, Server,
[Server, Method, Path, Elapsed])
end,
Result.
%%%----------------------------------------------------------------------
%%% HTTP helpers
%%%----------------------------------------------------------------------
to_list(V) when is_binary(V) ->
binary_to_list(V);
to_list(V) when is_list(V) ->
V.
encode_json(Content) ->
case catch jiffy:encode(Content) of
{'EXIT', Reason} ->
{error, {invalid_payload, Content, Reason}};
Encoded ->
Encoded
end.
decode_json(<<>>) -> [];
decode_json(<<" ">>) -> [];
decode_json(<<"\r\n">>) -> [];
decode_json(Data) -> jiffy:decode(Data).
custom_headers(Server) ->
case ejabberd_option:ext_api_headers(Server) of
<<>> ->
[];
Hdrs ->
lists:foldr(fun(Hdr, Acc) ->
case binary:split(Hdr, <<":">>) of
[K, V] -> [{binary_to_list(K), binary_to_list(V)}|Acc];
_ -> Acc
end
end, [], binary:split(Hdrs, <<",">>))
end.
base_url(Server, Path) ->
BPath = case iolist_to_binary(Path) of
<<$/, Ok/binary>> -> Ok;
Ok -> Ok
end,
Url = case BPath of
<<"http", _/binary>> -> BPath;
_ ->
Base = ejabberd_option:ext_api_url(Server),
case binary:last(Base) of
$/ -> <<Base/binary, BPath/binary>>;
_ -> <<Base/binary, "/", BPath/binary>>
end
end,
case binary:last(Url) of
47 -> binary_part(Url, 0, size(Url)-1);
_ -> Url
end.
url(Url, []) ->
Url;
url(Url, Params) ->
L = [<<"&", (iolist_to_binary(Key))/binary, "=",
(misc:url_encode(Value))/binary>>
|| {Key, Value} <- Params],
<<$&, Encoded/binary>> = iolist_to_binary(L),
<<Url/binary, $?, Encoded/binary>>.
url(Server, Path, Params) ->
case binary:split(base_url(Server, Path), <<"?">>) of
[Url] ->
url(Url, Params);
[Url, Extra] ->
Custom = [list_to_tuple(binary:split(P, <<"=">>))
|| P <- binary:split(Extra, <<"&">>, [global])],
url(Url, Custom++Params)
end.
