client side possibility?

[deviantmk]

hello

is there a library or a way to use javascript websocket to listen on a channel?
i am getting an net::ERR_EMPTY_RESPONSE

thanks

[jkarneges]

Of course. :) If you create WebSocket endpoints with Pushpin, then any WebSocket clients can connect to them, including the JavaScript WebSocket object in the browser.

Creating WebSocket endpoints requires server development though, to react to Pushpin's proxied events. Did you write any such code yet? If not, you can try Pushpin's test mode, which lets you connect and publish without having to write backend code.

First make sure your routes file is routing to the internal test service (this is the default out of the box):

* test

The test mode has a WebSocket endpoint living at /ws that automatically subscribes to a channel called test. Connect to it:

var ws = new WebSocket('ws://localhost:7999/ws');
ws.onmessage = function (message) {
  console.log(message.data);
};

Then from a terminal, you can publish using the pushpin-publish command line tool:

pushpin-publish test "hello world"

Please note that in a real application you would write backend code instead of using the test mode.

[deviantmk]

wow thats great
i had no idea about this
thanks

[deviantmk]

sorry to reopen this but i am getting some errors

i botted a docker pushpin container and i created a ws server in GO server, with javascript ws i tried to connect to the go server

but the ws connection is dropped

WebSocket connection to 'ws://localhost:8080/' failed: Error during WebSocket handshake: 'Sec-WebSocket-Extensions' header value is rejected by the parser: grip; message-prefix=""

and i get this error on the server

http: panic serving [::1]:5307: Publish failed with: Post 0.0.0.0:5561/publish/: unsupported protocol scheme ""
goroutine 5 [running]:
net/http.(*conn).serve.func1(0xc08204a100)
        C:/Go/src/net/http/server.go:1389 +0xc8
panic(0x6c6f20, 0xc0820b21a0)
        C:/Go/src/runtime/panic.go:426 +0x4f7
main.GripWebSocketHandler(0x2885760, 0xc082033790, 0xc0820a61c0)
        F:/projects/go/pushpin/main.go:40 +0x87f
net/http.HandlerFunc.ServeHTTP(0x85f290, 0x2885760, 0xc082033790, 0xc0820a61c0)
        C:/Go/src/net/http/server.go:1618 +0x41
net/http.(*ServeMux).ServeHTTP(0xc082058780, 0x2885760, 0xc082033790, 0xc0820a61c0)
        C:/Go/src/net/http/server.go:1910 +0x184
net/http.serverHandler.ServeHTTP(0xc08204a080, 0x2885760, 0xc082033790, 0xc0820a61c0)
        C:/Go/src/net/http/server.go:2081 +0x1a5
net/http.(*conn).serve(0xc08204a100)
        C:/Go/src/net/http/server.go:1472 +0xf35
created by net/http.(*Server).Serve
        C:/Go/src/net/http/server.go:2137 +0x455

---

apparently i mixd things up, ws://localhost:7999/ was the right client port

but now i am getting

WebSocket connection to 'ws://localhost:7999/channel' failed: Error during WebSocket handshake: Unexpected response code: 502

or

Error while proxying to origin. while accessing with HTTP get request which i think shows me that its the right url/port

[jkarneges]

What does your routes file look like? Should Pushpin speak to your backend server using HTTP or WebSocket? (you mention a "ws server in GO" so I just want to be sure).

[deviantmk]

hello
i have not yet touched the routes file because there were no instructions on the docker image, i am booting a linode instance and will test directly again

[deviantmk]

so what you described above with * test, should work without a server?
i am unable to get that result from the docker image

var ws = new WebSocket('ws://localhost:7999/ws');
ws.onmessage = function (message) {
  console.log(message.data);
};

WebSocket connection to 'ws://localhost:7999/ws' failed: Error during WebSocket handshake: Unexpected response code: 502

[deviantmk]

good news, directly from a linode instance works.
i am maybe doing something wrong with docker, looks like this

PORTS                                   NAMES
5560-5563/tcp, 0.0.0.0:7999->7999/tcp   pushpin

i will investigate further

[jkarneges]

The docker image routes to app:8080 instead of the internal test service. See the Dockerfile. You can set the target environment variable when running the image to have it route somewhere else.

[deviantmk]

that makes sense
thanks a bunch