cowboy 'GET' request variables values - erlang

Please tell me, how I can get the variables values of the GET request
I do so:
{Method, Req2} = cowboy_req:method(Req),
{FwdIPRaw, Req3} = cowboy_req:header(<<"x-forwarded-for">>, Req2),
{ClientCookie, Req4} = cowboy_req:cookie(<<"cook">>, Req3),
{ok, GetVals, Req5} = cowboy_req:qs_vals(Req4),
MessageId = proplists:get_value(<<"mid">>, GetVals),
EchoName = proplists:get_value(<<"m">>, GetVals),
{ok, Req5, State}.
But I get an error: qs_vals - undefined

For current cowboy version (0.9.0) documentation says that cowboy_req:qs_vals(Req4) returns {QsVals, Req5} where QsVals can be [] (empty list).
So try 0.9.0 cowboy version and fix call {ok, GetVals, Req5} = cowboy_req:qs_vals(Req4) to {GetVals, Req5} = cowboy_req:qs_vals(Req4).

Related

Elixir marshal ISO 8583 message error with Erlang library

I am new to elixir and I need to create ISO 8583 client with this language and Phoenix framework. I found an Erlang library for it from stackoverflow thread here, compiled successfully and followed the example in the repository here but got error when marshaling the message. Here is my Elixir code to marshal the message:
msg1 = :erl8583_message.new()
msg2 = :erl8583_message.set_mti("0800", msg1)
msg3 = :erl8583_message.set(3, "300000", msg2)
msg4 = :erl8583_message.set(24, "045", msg3)
msg5 = :erl8583_message.set(41, "11111111", msg4)
msg6 = :erl8583_message.set(42, "222222222222222", msg5)
msg7 = :erl8583_message.set(63, "This is a Test Message", msg6)
marshalled = :erl8583_marshaller_ascii.marshal(msg7)
That's just an elixir version from the example on the repo. This is the error I've got when running the app:
[error] #PID<0.438.0> running TestlangIsoClientWeb.Endpoint (cowboy_protocol) terminated
Server: 127.0.0.1:4001 (http)
Request: POST /api/process
** (exit) an exception was raised:
** (FunctionClauseError) no function clause matching in :erl8583_marshaller_ascii.marshal_data_element/2
(erl8583) /home/muhammad/Workspace/testlang/testlang_iso_client/deps/erl8583/src/erl8583_marshaller_ascii.erl:168: :erl8583_marshaller_ascii.marshal_data_element({:n, :fixed, 4}, "0800")
(erl8583) /home/muhammad/Workspace/testlang/testlang_iso_client/deps/erl8583/src/erl8583_marshaller.erl:108: :erl8583_marshaller.marshal/2
(testlang_iso_client) lib/testlang_iso_client_web/controllers/my_controller.ex:61: TestlangIsoClientWeb.MyController.process/2
(testlang_iso_client) lib/testlang_iso_client_web/controllers/my_controller.ex:1: TestlangIsoClientWeb.MyController.action/2
(testlang_iso_client) lib/testlang_iso_client_web/controllers/my_controller.ex:1: TestlangIsoClientWeb.MyController.phoenix_controller_pipeline/2
(testlang_iso_client) lib/testlang_iso_client_web/endpoint.ex:1: TestlangIsoClientWeb.Endpoint.instrument/4
(phoenix) lib/phoenix/router.ex:278: Phoenix.Router.__call__/1
(testlang_iso_client) lib/testlang_iso_client_web/endpoint.ex:1: TestlangIsoClientWeb.Endpoint.plug_builder_call/2
(testlang_iso_client) lib/testlang_iso_client_web/endpoint.ex:1: TestlangIsoClientWeb.Endpoint.call/2
(plug) lib/plug/adapters/cowboy/handler.ex:16: Plug.Adapters.Cowboy.Handler.upgrade/4
(cowboy) /home/muhammad/Workspace/testlang/testlang_iso_client/deps/cowboy/src/cowboy_protocol.erl:442: :cowboy_protocol.execute/4
Is there something I missed to make it work? Any help would be very appreciated.
Updated
I have tried to changed the string parameter to charlist, but still got the same error. Here is the code snippet:
def test(conn, _params) do
IO.puts("Test")
msg1 = :erl8583_message.new()
msg2 = :erl8583_message.set_mti('0800', msg1)
msg3 = :erl8583_message.set(3, '300000', msg2)
msg4 = :erl8583_message.set(24, '045', msg3)
msg5 = :erl8583_message.set(41, '11111111', msg4)
msg6 = :erl8583_message.set(42, '222222222222222', msg5)
msg7 = :erl8583_message.set(63, 'This is a Test Message', msg6)
marshalled = :erl8583_marshaller_ascii.marshal(msg7)
json(conn, %{status: "ok"})
end
Here is the function erl8583_marshaller.erl:108 mentioned in the stacktrace:
marshal(Message, MarshalHandlers) ->
OptionsRecord = parse_options(MarshalHandlers, #marshal_options{}),
{Marshalled1, Message1} = init_marshalling(OptionsRecord, Message),
MarshalledMti = encode_mti(OptionsRecord, Message1), % --- Line 108
Marshalled2 = <<Marshalled1/binary, MarshalledMti/binary>>,
{MarshalledBitmap, Message2} = encode_bitmap(OptionsRecord, Message1),
Marshalled3 = <<Marshalled2/binary, MarshalledBitmap/binary>>,
MarshalledFields = encode_fields(OptionsRecord, Message2),
Marshalled4 = <<Marshalled3/binary, MarshalledFields/binary>>,
end_marshalling(OptionsRecord, Message2, Marshalled4).
And here is the function erl8583_marshaller_ascii.erl:168 mentioned in the stacktrace:
%%
%% Local Functions
%%
marshal_data_element({n, llvar, Length}, FieldValue) when length(FieldValue) =< Length ->
erl8583_convert:integer_to_string(length(FieldValue), 2) ++ FieldValue;
I don't understand why the call to that function was failed to match with parameters {:n, :fixed, 4}, "0800" that was sent from my function. I have tried to change the double quotes to single quotes with no success. Is there any other suggestions what am I supposed to do?
there may be a bug in the code.
you can reference this issue here
there is one elixir library out which is relatively new.
its called ale8583.
documentation is still coming out on this one but looks very promising.
you can check it out.
Try passing charlists instead of strings:
msg1 = :erl8583_message.new()
msg2 = :erl8583_message.set_mti('0800', msg1)
msg3 = :erl8583_message.set(3, '300000', msg2)
msg4 = :erl8583_message.set(24, '045', msg3)
msg5 = :erl8583_message.set(41, '11111111', msg4)
msg6 = :erl8583_message.set(42, '222222222222222', msg5)
msg7 = :erl8583_message.set(63, 'This is a Test Message', msg6)
marshalled = :erl8583_marshaller_ascii.marshal(msg7)
There is potential for confusion here:
What Erlang calls "strings" and puts in double quotes ("foo"), Elixir calls "charlists" and puts in single quotes ('foo').
What Elixir calls "strings" and puts in double quotes ("foo"), Erlang calls "binaries" and puts in double quotes plus angle brackets (<<"foo">>).
It seems like the erl8583 library expects Erlang strings throughout.

Ejabberd - Route message to users in offline_message_hook

I want to build a customer support chat app. There are users and an admin. Below admin there are multiple sub-admins. Initially the chat is initiated with admin only, but if the admin is offline I need to route the message to sub-admins.
offline_message_hook hook serves the purpose. I'll check if the To is admin, then I need to route the Packet to one of the sub-admins. How do I route/send the packet to other user within offline_message_hook. In short how do I change the To from the packet so that the packet is re-directed to the new sub-admin?
Here is what I've tried:-
offline_message_hook({_Action, #message{from = Peer, to = To} = Pkt} = Acc) ->
?INFO_MSG("Inside offline", []),
ejabberd_router:route(From, To, Packet),
ok.
I'm using ejabberd 17.04.105.
Update
After following user2610053's advice, I did this:-
-spec offline_message_hook({any(), message()}) -> {any(), message()}.
offline_message_hook({_Action, Msg} = Acc) ->
ejabberd_router:route(xmpp:set_to(Msg, 'praful#localhost')),
{routed, Msg}.
Following is the error:-
15:13:12.291 [error] failed to route packet:
#message{id = <<"purple187f6502">>,type = chat,lang = <<"en">>,
from = {jid,<<"praful2">>,<<"localhost">>,<<"Prafuls-MacBook-Pro">>,
<<"praful2">>,<<"localhost">>,<<"Prafuls-MacBook-Pro">>},
to = praful#localhost,subject = [],
body = [#text{lang = <<>>,data = <<"co=umon">>}],
thread = undefined,
sub_els = [{xmlel,<<"active">>,
[{<<"xmlns">>,
<<"http://jabber.org/protocol/chatstates">>}],
[]}],
meta = #{ip => {0,0,0,0,0,0,0,1}}}
Reason = {error,{{badrecord,jid},[{ejabberd_router,do_route,1,[{file,"src/ejabberd_router.erl"},{line,343}]},{ejabberd_router,route,1,[{file,"src/ejabberd_router.erl"},{line,87}]},{mod_sunshine,offline_message_hook,1,[{file,"src/mod_sunshine.erl"},{line,24}]},{ejabberd_hooks,safe_apply,4,[{file,"src/ejabberd_hooks.erl"},{line,380}]},{ejabberd_hooks,run_fold1,4,[{file,"src/ejabberd_hooks.erl"},{line,364}]},{ejabberd_sm,route,1,[{file,"src/ejabberd_sm.erl"},{line,138}]},{ejabberd_local,route,1,[{file,"src/ejabberd_local.erl"},{line,116}]},{ejabberd_router,do_route,1,[{file,"src/ejabberd_router.erl"},{line,348}]}]}}
The user praful#localhost exist. Please advice what exactly is wrong?
Update2 - `UserReceivePacket Hook
In user_receive_packet packet hook, upon using the same function ejabberd_router:route(xmpp:set_to(Packet, jid:decode("praful#localhost"))), it throws an error saying :-
Hook user_receive_packet crashed when running mod_sunshine:user_receive_packet/1:
** Reason = {error,function_clause,[{jid,decode,[{file,"src/jid.erl"},{line,132}],["praful#localhost"]},{mod_sunshine,user_receive_packet,[{file,"src/mod_sunshine.erl"},{line,29}],1},{ejabberd_hooks,safe_apply,[{file,"src/ejabberd_hooks.erl"},{line,380}],4},{ejabberd_hooks,run_fold1,[{file,"src/ejabberd_hooks.erl"},{line,364}],4},{ejabberd_c2s,process_info,[{file,"src/ejabberd_c2s.erl"},{line,231}],2},{ejabberd_hooks,safe_apply,[{file,"src/ejabberd_hooks.erl"},{line,380}],4},{ejabberd_hooks,run_fold1,[{file,"src/ejabberd_hooks.erl"},{line,364}],4},{xmpp_stream_in,handle_info,[{file,"src/xmpp_stream_in.erl"},{line,373}],2}]}
So, I read about function_clause, but couldnt understand the same. What exactly is wrong over here?
I think you're asking about xmpp:set_to/2. Here is an example:
offline_message_hook({_Action, Msg} = Acc) ->
SubAdmins = get_sub_admins(Msg#message.to),
lists:foreach(
fun(Admin) ->
ejabberd_router:route(xmpp:set_to(Msg, Admin))
end, Admins),
{routed, Msg}.

Can't get httpc basic auth example to work with https

This is my first time using erlang and I decided to try and write a wrapper for an API. Here's what I've got so far:-
-module(my_api_wrapper).
%% API exports
-export([auth/0]).
auth() ->
application:start(inets),
application:start(ssl),
AuthStr = base64:encode_to_string("username:password"),
Method = post,
URL = "https://api.endpoint.com/auth",
Header = [{"Authorization", "Basic " ++ AuthStr}],
Type = "application/json",
Body = "{\"grant_type\":\"client_credentials\"}",
HTTPOptions = [],
Options = [],
httpc:request(Method, {URL, Header, Type, Body}, HTTPOptions, Options).
When testing this at the shell I get an error:-
{error,{failed_connect,[{to_address,{"api.endpoint.com",
443}},
{inet,[inet],closed}]}}
I can't figure out what I'm doing wrong here! I'm running this version Erlang/OTP 19 [erts-8.0.2]. Any help appreciated.
For anyone who it might help - here's exactly what I changed to make the code in my original question work - thanks to Dogbert for his comment above.
-module(my_api_wrapper).
%% API exports
-export([auth/0]).
auth() ->
application:start(inets),
application:start(ssl),
AuthStr = base64:encode_to_string("username:password"),
Method = post,
URL = "https://api.endpoint.com/auth",
Header = [{"Authorization", "Basic " ++ AuthStr}],
Type = "application/json",
Body = "{\"grant_type\":\"client_credentials\"}",
% ADD SSL CONFIG BELOW!
HTTPOptions = [{ssl,[{versions, ['tlsv1.2']}]}],
Options = [],
httpc:request(Method, {URL, Header, Type, Body}, HTTPOptions, Options).

Ejabberd 13.12 how to add element XMPP Packet?

I am using ejabberd hook named "filter-packet" to make a module. Here I want to add an element to packet. How to do it? My Code is -
on_filter_packet({From, To, Packet}=Input) ->
Type = xml:get_tag_attr_s(list_to_binary("type"), Packet),
if (Type == <<"groupchat">>) ->
?INFO_MSG("type is group chat", []),
NPacket={Packet, [{xmlelement, "time",
[],
[{xmlcdata, "testtime"}]}]},
{From, To, NPacket};
true ->
Input
end.
This code is giving error of bad match. Any Help ?
13.12 uses different type for xmlelement.
Packet is a type of record #xmlel, so you need to insert new element to Packet#xmlel.children.
on_filter_packet({From, To, #xmlel{ children=OldChildren } = Packet}=Input) ->
...
TimeElem = #xmlel{ name = <<"time">>,
children =
[{xmlcdata, <<"testtime">>}]},
NPacket = Packet#xmlel{ children = [TimeElem|OldChildren] },
...
Not tested, but will work.

erlang mime get To field

I try to get TO: user#mail.com field from mime mail message.
I have code:
parse_to(Data) ->
List = string:tokens(Data, ":"),
Sep1 = lists:map(fun(H) ->string:tokens(H, ":") end, List),
io:format(Sep1),
Sep2 = lists:filter(fun ([K | _]) -> K == "To" end, Sep1),
ListAddress = lists:append(Sep2),
[_ | Tail] = ListAddress,
lists:map(fun(Address) -> string:tokens(Address, ",") end, Tail).
If i have short message for example: https://gist.github.com/865910
I got in io:format(Sep1) https://gist.github.com/865905, it's ok all without :
But if i have long message with attachment: - https://gist.github.com/865914
I got in io:format(Sep1) - https://gist.github.com/865906 everything remains the same as it was with :
What's wrong? Why shot message normal parse and big message not parsed?
When i try use regexp:
List = binary_to_list(Binary),
re:run(List, "^To: (.)*$", [multiline, {capture, all_but_first, list}]).
I get only {match, ["m"]}
Why?
Thank you.
Try a regular expression:
1> Data = <<"...">> % Your long message
<<"...">>
2> re:run(Data, <<"^To: (.*)$">>, [multiline, {capture, all_but_first, binary}]).
{match,[<<"shk#shk.dyndns-mail.com">>]}

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