DNS And Websocket For Fun

A toy server that acts as a DNS proxy and HTTP server (including WebSocket server).

Overview

• DNS request log will be broadcasted to all connected WebSocket clients. To demonstrate server-initiated events.
• It also receives an incoming free text message from the WebSocket client and the WebSocket hub will broadcast those messages to all connected WebSocket clients. To demonstrate client-initiated events.
• The internal mechanism for passing data between goroutine is using go-channel.
• Implements share memory by communicating.

NOTE: this repository is a sample for the Golang sharing session showcase, mainly to cover WebSocket and concurrent programming (using goroutine and channel).

Build And Execute

Requirement

• Go >= v1.16

Build

All dependencies are included in vendor folder (go mod tidy && go mod vendor), so you can just clone this repo and then:

• go build -trimpath -a -mod=vendor -tags "osusergo,netgo" -ldflags '-w -s -v' -o ./build/server ./main.go

Execute

• ./build/server

For available arguments, use ./build/server -h.

Demo

• Open http://127.0.0.1:8080 to see the web page, it will open new WebSocket session from the web browser.
• Point your DNS resolver to 127.0.0.1 port 53 Or simple test using dig command, for example: dig MX simukti.net @127.0.0.1.

To simulate another WebSocket client connected, you can use one of these tools to connect to the WebSocket server at ws://127.0.0.1:8080/ws:

• WebSocket King Client (Chrome extension)
• Weasel (Firefox extension)
• Websocat CLI

LICENSE

MIT