typedserver/ts/servertools/classes.handlerproxy.ts
2023-03-30 15:15:48 +02:00

78 lines
2.4 KiB
TypeScript

import * as plugins from '../typedserver.plugins.js';
import { Handler } from './classes.handler.js';
import * as interfaces from '../interfaces/index.js';
export class HandlerProxy extends Handler {
/**
* The constuctor of HandlerProxy
* @param remoteMountPointArg
*/
constructor(
remoteMountPointArg: string,
optionsArg?: {
responseModifier?: interfaces.TResponseModifier;
headers?: { [key: string]: string };
}
) {
super('ALL', async (req, res) => {
const relativeRequestPath = req.path.slice(req.route.path.length - 1);
const proxyRequestUrl = remoteMountPointArg + relativeRequestPath;
console.log(`proxy ${req.path} to ${proxyRequestUrl}`);
let proxiedResponse: plugins.smartrequest.IExtendedIncomingMessage;
try {
proxiedResponse = await plugins.smartrequest.request(proxyRequestUrl, {
method: req.method,
autoJsonParse: false,
});
} catch {
res.end('failed to fullfill request');
return;
}
for (const header of Object.keys(proxiedResponse.headers)) {
res.set(header, proxiedResponse.headers[header] as string);
}
// set additional headers
if (optionsArg && optionsArg.headers) {
for (const key of Object.keys(optionsArg.headers)) {
res.set(key, optionsArg.headers[key]);
}
}
let responseToSend: string = proxiedResponse.body;
if (typeof responseToSend !== 'string') {
console.log(proxyRequestUrl);
console.log(responseToSend);
throw new Error(`Proxied response is not a string, but ${typeof responseToSend}`);
}
if (optionsArg && optionsArg.responseModifier) {
const modifiedResponse = await optionsArg.responseModifier({
headers: res.getHeaders(),
path: req.path,
responseContent: responseToSend,
});
// headers
for (const key of Object.keys(res.getHeaders())) {
if (!modifiedResponse.headers[key]) {
res.removeHeader(key);
}
}
for (const key of Object.keys(modifiedResponse.headers)) {
res.setHeader(key, modifiedResponse.headers[key]);
}
// responseContent
responseToSend = modifiedResponse.responseContent;
}
res.status(200);
res.write(responseToSend);
res.end();
});
}
}