nodeJs use express-http-proxy forwards the request

Reprinted from: https://www.cnblogs.com/xiaoliwang/p/10195923.html

 

The development process often required to do the forwarding layer nodeJs

Use express with express-http-proxy can easily complete forward

Use process:

Installation of express-http-proxy

npm install express --save
npm install express-http-proxy --save

Create a proxy instance

var proxy = require('express-http-proxy');

The client requests convey to http: // localhost: 3001:

app.use ( '/ API', Proxy ( 'HTTP: // localhost: 3001', { 
    // filter (optional) 
    filter: function (REQ, RES) { 
        return req.method == 'the GET'; 
    } 
    // path resolution request (optional) 
    proxyReqPathResolver: function (REQ) { 

        the console.log ( `request path: $ {req.url}`); // request path: / Article This article was / List 

        return `$ {REQ. ? url} token = 123456` // request forwarding path:? / Article This article was / token = 123456 List 
    }, 
    // returns the data processing, if the asynchronous operation procedure should return Promise (optional) 
    userResDecorator: function (proxyRes, proxyResData, UserReq , UserRes) { 
        // synchronization 
        Data = the JSON.parse (proxyResData.toString ( 'UTF8')); 
        data.newProperty = 'in my field adequately Data'; 
        return the JSON.stringify (Data);
        //asynchronous
        return new Promise(function(resolve) {
            proxyResData.funkyMessage = 'oi io oo ii';
            setTimeout(function() {
                resolve(proxyResData);
            }, 200);
        });
    },
}))

If you have multiple servers, you can take advantage of express-http-proxy load balancing

app.use ( '/ API', Proxy (selectProxyHost)) 
// server randomly selected forwarding 
function selectProxyHost () { 
    return (new new a Date ()% 2) 'http://google.com':? 'HTTP: // Altavista.com '; 
}