在Golang中处理WebSocket通信的设计实践

Question

I am new to go and trying to learn it by replacing a nodejs server. My nodejs server had the following components:

1. It received a websocket message from a client. The client would provide a unique ID and a key for the message. The server would process the message based on the key (much like a REST interface would) and return a message to the client with the unique ID so that the client would know which message the server was responding to.

2. For some of the messages, the server would spawn an external process (one for each connection). The server would then act as a "client" to the spawned process, sending JSON messages with unique IDs and receiving back data. The server in this instance acts as an intermediary between the spawned process and the client.

On node it was trivial to get this to work generically. I simply added the spawned process to the connection in my "main" and used callbacks in the main. The websocket server module and the module governing the spawned process communication had no direct interaction and were completely generic.

However, while I have a websocket package and a spawn package that work well in go, I haven't been able to figure out a good way to generically create a spawned process per websocket connection. I've thought of passing callbacks and inits but this method seems hackish. I recognize that node and go probably require different strategies in programming but I can't think of a good "go" way of doing this. I welcome any suggestions!

Answer 1

1. You describe how http protocol works, means request-response. If that all you need you may feel good with just keep-alive connections. Websocket is async in nature, messages aren't assume responses. Use-case is server-send-events for example.
2. In Go server uses fire-and-forget strategy. It accepts connection, spawns goroutine to handle it, forgets it and listens for a new. Spawned goroutine upgrades connection to websocket and then serves client itself without any intermediary.