refactor: Refactor simplify types for proxy upgrade call

Signed-off-by: Carlos Esteban Lopez <lcarlosesteb@vmware.com>

plugins/kubernetes-backend/package.json

@@ -75,7 +75,6 @@
     "express-promise-router": "^4.1.0",
     "fs-extra": "10.1.0",
     "helmet": "^6.0.0",
-    "http-proxy": "^1.18.1",
     "http-proxy-middleware": "^2.0.6",
     "lodash": "^4.17.21",
     "luxon": "^3.0.0",

plugins/kubernetes-backend/src/service/KubernetesProxy.ts

@@ -27,14 +27,12 @@ import {
   PermissionEvaluator,
 } from '@backstage/plugin-permission-common';
 import { bufferFromFileOrString } from '@kubernetes/client-node';
-import { IncomingMessage, ServerResponse } from 'http';
-import Server from 'http-proxy';
-import { createProxyMiddleware } from 'http-proxy-middleware';
+import { createProxyMiddleware, RequestHandler } from 'http-proxy-middleware';
 import { Logger } from 'winston';
 import { AuthenticationStrategy } from '../auth';
 import { ClusterDetails, KubernetesClustersSupplier } from '../types/types';
 
-import type { Request, RequestHandler } from 'express';
+import type { Request } from 'express';
 
 export const APPLICATION_JSON: string = 'application/json';
 
@@ -123,22 +121,14 @@ export class KubernetesProxy {
       }
 
       const middleware = await this.getMiddleware(req);
+
+      // If req is an upgrade handshake, use middleware upgrade instead of http request handler https://github.com/chimurai/http-proxy-middleware#external-websocket-upgrade
       if (
         req.header('connection')?.toLowerCase() === 'upgrade' &&
         req.header('upgrade')?.toLowerCase() === 'websocket'
       ) {
-        type IPartialUpgradeHandler = (
-          ...args: Partial<
-            Parameters<
-              Server<IncomingMessage, ServerResponse<IncomingMessage>>['ws']
-            >
-          >
-        ) => void;
-        (
-          middleware as unknown as {
-            upgrade: IPartialUpgradeHandler;
-          }
-        ).upgrade(req, req.socket);
+        // Missing the `head`, since it's optional we pass undefined to avoid type issues
+        middleware.upgrade!(req, req.socket, undefined);
       } else {
         middleware(req, res, next);
       }