Fix ssl alert crashes

[tonnenpinguin]

Hey all!

After upgrading to OTP 25 we noticed failing connections. The problem is that after the connection receives an SSL alert it completely stops trying to reconnect until the application is restarted.

16:11:11.635 [notice] TLS :client: In state :connection received SERVER ALERT: Fatal - Certificate required

 
16:11:11.652 [error] GenServer #PID<0.415.0> terminating
** (CaseClauseError) no case clause matching: {:error, %Mint.HTTP1{buffer: "", host: "0.0.0.0", mode: :active, port: 4001, private: %{extensions: [], scheme: :wss, sec_websocket_key: "KQvsbsvdPPlqt1e5LmN/5A=="}, proxy_headers: [], request: %{body: nil, connection: [], content_length: nil, data_buffer: [], headers_buffer: [], method: "GET", ref: #Reference<0.2518903565.3178758153.185166>, state: :status, status: nil, transfer_encoding: [], version: nil}, requests: {[], []}, scheme_as_string: "https", socket: {:sslsocket, {:gen_tcp, #Port<0.7>, :tls_connection, :undefined}, [#PID<0.426.0>, #PID<0.425.0>]}, state: :closed, streaming_request: nil, transport: Mint.Core.Transport.SSL}, %Mint.TransportError{reason: {:tls_alert, {:certificate_required, 'TLS client: In state connection received SERVER ALERT: Fatal - Certificate required\n'}}}, []}
    (slipstream 0.8.4) lib/slipstream/connection/pipeline.ex:140: Slipstream.Connection.Pipeline.decode_message/1
    (slipstream 0.8.4) lib/slipstream/connection/pipeline.ex:34: anonymous fn/1 in Slipstream.Connection.Pipeline.handle/2
    (slipstream 0.8.4) lib/slipstream/connection/telemetry.ex:29: anonymous fn/2 in Slipstream.Connection.Telemetry.span/2
    (telemetry 1.0.0) /Users/tonnenpinguin/src/poser/deps/telemetry/src/telemetry.erl:293: :telemetry.span/3
    (slipstream 0.8.4) lib/slipstream/connection/telemetry.ex:25: Slipstream.Connection.Telemetry.span/2
    (stdlib 4.0) gen_server.erl:1120: :gen_server.try_dispatch/4
    (stdlib 4.0) gen_server.erl:1197: :gen_server.handle_msg/6
    (stdlib 4.0) proc_lib.erl:240: :proc_lib.init_p_do_apply/3
Last message: {:ssl_error, {:sslsocket, {:gen_tcp, #Port<0.7>, :tls_connection, :undefined}, [#PID<0.426.0>, #PID<0.425.0>]}, {:tls_alert, {:certificate_required, 'TLS client: In state connection received SERVER ALERT: Fatal - Certificate required\n'}}}
State: %Slipstream.Connection.State{client_pid: #PID<0.414.0>, client_ref: #Reference<0.2518903565.3178758150.185680>, config: %Slipstream.Configuration{extensions: [], headers: [], heartbeat_interval_msec: 30000, json_parser: Jason, mint_opts: [protocols: [:http1], transport_opts: [cacerts: [CACERTS], keyfile: "nerves-hub/poser-key.pem", certfile: "nerves-hub/poser-cert.pem", verify: :verify_peer, server_name_indication: 'device.nerves-hub.org']], reconnect_after_msec: [1267, 2526, 4370, 11067, 23534, 40850, 64159], rejoin_after_msec: [5000], test_mode?: false, uri: %URI{authority: "0.0.0.0:4001", fragment: nil, host: "0.0.0.0", path: "/socket/websocket", port: 4001, query: nil, scheme: "wss", userinfo: nil}}, conn: %Mint.HTTP1{buffer: "", host: "0.0.0.0", mode: :active, port: 4001, private: %{extensions: [], scheme: :wss, sec_websocket_key: "KQvsbsvdPPlqt1e5LmN/5A=="}, proxy_headers: [], request: %{body: nil, connection: [], content_length: nil, data_buffer: [], headers_buffer: [], method: "GET", ref: #Reference<0.2518903565.3178758153.185166>, state: :status, status: nil, transfer_encoding: [], version: nil}, requests: {[], []}, scheme_as_string: "https", socket: {:sslsocket, {:gen_tcp, #Port<0.7>, :tls_connection, :undefined}, [#PID<0.426.0>, #PID<0.425.0>]}, state: :open, streaming_request: nil, transport: Mint.Core.Transport.SSL}, connection_id: "5e1f7e72403ec163", current_ref: 0, current_ref_str: "0", heartbeat_ref: nil, heartbeat_timer: nil, join_params: nil, joins: %{}, leaves: %{}, metadata: %{connection_id: "5e1f7e72403ec163", start_time: ~U[2022-06-22 14:11:11.417027Z], start_time_monotonic: -576460750894614603, state: %Slipstream.Connection.State{client_pid: #PID<0.414.0>, client_ref: #Reference<0.2518903565.3178758150.185680>, config: %Slipstream.Configuration{extensions: [], headers: [], heartbeat_interval_msec: 30000, json_parser: Jason, mint_opts: [protocols: [:http1], transport_opts: [cacerts: [CACERTS], keyfile: "nerves-hub/poser-key.pem", certfile: "nerves-hub/poser-cert.pem", verify: :verify_peer, server_name_indication: 'device.nerves-hub.org']], reconnect_after_msec: [1267, 2526, 4370, 11067, 23534, 40850, 64159], rejoin_after_msec: [5000], test_mode?: false, uri: %URI{authority: "0.0.0.0:4001", fragment: nil, host: "0.0.0.0", path: "/socket/websocket", port: 4001, query: nil, scheme: "wss", userinfo: nil}}, conn: nil, connection_id: "5e1f7e72403ec163", current_ref: 0, current_ref_str: "0", heartbeat_ref: nil, heartbeat_timer: nil, join_params: nil, joins: %{}, leaves: %{}, metadata: nil, request_ref: nil, status: :opened, trace_id: "3c882d640b72cecbbb740abb580d7419", websocket: nil}, trace_id: "3c882d640b72cecbbb740abb580d7419"}, request_ref: #Reference<0.2518903565.3178758153.185166>, status: :opened, trace_id: "3c882d640b72cecbbb740abb580d7419", websocket: nil}

This patch fixes this and causes slipstream to at least keep retrying.

I'm new to the project and didn't quite know where to put a test, so pointers would be highly appreciated :)

[the-mikedavis]

Hmm it might be difficult to come up with a good test case for this. I would be comfortable without a test in this case - based on the stack trace I think this looks good and it's just error handling anyways ¯\_(ツ)_/¯

[tonnenpinguin]

Thanks for the quick review! :)

I committed your suggested change, fixed the formatting and manually double checked that everything is still working

[the-mikedavis]

Thanks for the fix, this is lovely! 🚀