CORS or nginx proxy or interface development that cannot be solved by online cross-domain front end

Let me give you a link. This question has been fiercely answered
https://codeshelper.com/q/10.

quickly and directly using nginx proxy

in this case, it seems that we can only reverse proxy

for the time being, use JsonBird to solve it. However, there is a certain delay. Currently, we have not found a better way

CORS (Cross-Origin Resource Sharing, cross-source resource sharing) HTTP access control technology, but there is a compatibility problem.

ask the bosses to spray lightly, our front-end and front-end separate projects, running in an Express service, the code is as follows, the middleware used by the agent, http-proxy-middleware.
`var express = require ('express');
var proxyMiddleware = require (' http-proxy-middleware');
var apiHost =' http://172.16.0.249:8181';
var proxyTable = {
'/ v1mm: {

target: apiHost,
changeOrigin: true,

},
'/ preview': {

target: apiHost,
changeOrigin: true,

},
'/ download': {

target: apiHost,
changeOrigin: true,

}
};

var app = express ();
var port = 4000;
Object.keys (proxyTable) .forEach (function (context) {
var options = proxyTable [context];
if (typeof options = 'string') {

options = { target: options }

}
app.use (proxyMiddleware (options.filter | | context, options))
});
app.use (require ('connect-history-api-fallback') ());
app.use (express.static ('. / dist'));
var uri =' http://localhost:' + port;

var _ resolve;
var readyPromise = new Promise (function (resolve) {
_ resolve = resolve;
});

console.log ('> Starting prod server.' + uri);

var server = app.listen (port);

module.exports = {

ready: readyPromise,
close: function() {
  server.close()
}

}; `