如何使Node.js与Golang对话

Question

I am creating a web app in node.js and golang. I need to connect nodejs with golang code which talks to mongodb and returns data to node program. is there any way to connect so? I tried to use gonode API.This is my code using gonode API.

my node.js file contains below code:

var Go = require('gonode').Go;
var options = {
path : 'gofile.go',
initAtOnce : true,
}

var go = new Go(options,function(err){
if(err) throw err;

go.execute({commandText: 'Hello world from gonode!'}, function(result, response) {
        if(result.ok) {
            console.log('Go responded: ' + response.responseText);
        }
});

go.close();
});     `

And this is the code in my gofile.go file:

package main

import(
    gonode "github.com/jgranstrom/gonodepkg"
    json "github.com/jgranstrom/go-simplejson"
)

func main(){
    gonode.Start(process)
}

func process(cmd *json.Json) (response *json.Json) {    
    response, m := json.MakeMap()

    if(cmd.Get("commandText").MustString() == "Hello") {
        m["responseText"] = "Well hello there!"
    } else {
        m["responseText"] = "What?"
    }

    return
}

This is the error am getting while running as node node.js in terminal

events.js:72
        throw er; // Unhandled 'error' event
              ^
Error: write EPIPE
    at errnoException (net.js:905:11)
    at Object.afterWrite (net.js:721:19)

Answer 1

Based on a very cursive check of the gonode source code, the module seems to spawn go code as a child process and communicate through stdin/-out. EPIPE error means that the other end closed the stream. Based on this it might be that your go process exits prematurely.

You could try to debug the problem by modifying Command.prototype.execute in gonode/lib/command.js to print out the JSON that's sent to the go process. Then you can debug the go program by running it directly and giving it the same input via stdin.