Hi,
I’m newbie to Elixir + Phoenix world. I’ve started an open source project to help COVID-19 pandemic if you live in a community, like a share-house.

In the app, I don’t have a user system, not needed, however I need to add device feature in order to be able to send notification later. So, I want to know which device is connected. I’m going to create a unique device id for each client on first call and set it in the cookie (I’ve have a plug for that, coding is going on).

For test purpose, to make the code easier, I created a separated branch along with some explanation in the comments here: https://github.com/rainlab-inc/cothings/tree/socket-authentication which is created from this: https://github.com/rainlab-inc/cothings/tree/upgrade-phoenix-version-to-1.5

I’ve been following latest documentations for:

• Phoenix.Socket https://hexdocs.pm/phoenix/Phoenix.Socket.html
• Phoenix.Channels https://hexdocs.pm/phoenix/1.5.1/channels.html
• JS Client Library: https://hexdocs.pm/phoenix/js/

However I’m not able to receive the token in user_socket module. I get a very common error like this:

Server: localhost:4000 (http)
Request: GET /socket/websocket?vsn=2.0.0
** (exit) an exception was raised:
    ** (FunctionClauseError) no function clause matching in ColivingWeb.UserSocket.connect/3
        (coliving 0.1.0) lib/coliving_web/channels/user_socket.ex:6: ColivingWeb.UserSocket.connect(%{"vsn" => "2.0.0"}, %Phoenix.Socket{assigns: %{}, channel: nil, channel_pid: nil, endpoint: ColivingWeb.Endpoint, handler: ColivingWeb.UserSocket, id: nil, join_ref: nil, joined: false, private: %{}, pubsub_server: ColivingWeb.PubSub, ref: nil, serializer: Phoenix.Socket.V2.JSONSerializer, topic: nil, transport: :websocket, transport_pid: nil}, %{})
        (phoenix 1.5.1) lib/phoenix/socket.ex:572: Phoenix.Socket.user_connect/4
        (phoenix 1.5.1) lib/phoenix/socket.ex:434: Phoenix.Socket.__connect__/3
        (phoenix 1.5.1) lib/phoenix/transports/websocket.ex:32: Phoenix.Transports.WebSocket.connect/4
        (phoenix 1.5.1) lib/phoenix/endpoint/cowboy2_handler.ex:31: Phoenix.Endpoint.Cowboy2Handler.init/4
        (cowboy 2.7.0) coliving/deps/cowboy/src/cowboy_handler.erl:41: :cowboy_handler.execute/2
        (cowboy 2.7.0) coliving/deps/cowboy/src/cowboy_stream_h.erl:320: :cowboy_stream_h.execute/3
        (cowboy 2.7.0) coliving/deps/cowboy/src/cowboy_stream_h.erl:302: :cowboy_stream_h.request_process/3
        (stdlib 3.11.2) proc_lib.erl:249: :proc_lib.init_p_do_apply/3
[error] #PID<0.523.0> running ColivingWeb.Endpoint (connection #PID<0.522.0>, stream id 1) terminated

But if I do the solution that I found online, especially discussions from here, then I don’t get an authenticated socket connection.

For example adding this function in the user_socket module:

def connect(_params, socket, _connect_info), do: {:ok, socket }

You may check the commit history from the branches or following the links for the codes:

Creating token with a hard coded device_uuid: https://github.com/rainlab-inc/cothings/blob/socket-authentication/lib/coliving_web/templates/layout/app.html.eex#L12

JS Socket Client: https://github.com/rainlab-inc/cothings/blob/socket-authentication/assets/js/socket.js

User_Socket module: https://github.com/rainlab-inc/cothings/blob/socket-authentication/lib/coliving_web/channels/user_socket.ex

What do I miss from the documentations?

Thanks in advance for your help!