[Console] Fix overriding of host header name (#59143) (#59269)

* fix: only override hostname if none was provided

Copy the behaviour or Wreck.request from 7.4. This is a regression
for setting the Host header value.

* Refactor variable name

* [skip ci] Fix comment

src/plugins/console/server/lib/proxy_request.test.ts

@@ -30,11 +30,6 @@ describe(`Console's send request`, () => {
   beforeEach(() => {
     sandbox = sinon.createSandbox();
     stub = sandbox.stub(http, 'request').callsFake(() => {
-      fakeRequest = {
-        abort: sinon.stub(),
-        on() {},
-        once() {},
-      } as any;
       return fakeRequest;
     });
   });
@@ -45,6 +40,11 @@ describe(`Console's send request`, () => {
   });
 
   it('correctly implements timeout and abort mechanism', async () => {
+    fakeRequest = {
+      abort: sinon.stub(),
+      on() {},
+      once() {},
+    } as any;
     try {
       await proxyRequest({
         agent: null as any,
@@ -60,4 +60,55 @@ describe(`Console's send request`, () => {
       expect((fakeRequest.abort as sinon.SinonStub).calledOnce).toBe(true);
     }
   });
+
+  it('correctly sets the "host" header entry', async () => {
+    fakeRequest = {
+      abort: sinon.stub(),
+      on() {},
+      once(event: string, fn: any) {
+        if (event === 'response') {
+          return fn('done');
+        }
+      },
+    } as any;
+
+    // Don't set a host header this time
+    const result1 = await proxyRequest({
+      agent: null as any,
+      headers: {},
+      method: 'get',
+      payload: null as any,
+      timeout: 30000,
+      uri: new URL('http://noone.nowhere.none'),
+    });
+
+    expect(result1).toEqual('done');
+
+    const [httpRequestOptions1] = stub.firstCall.args;
+
+    expect((httpRequestOptions1 as any).headers).toEqual({
+      'content-type': 'application/json',
+      host: 'noone.nowhere.none', // Defaults to the provided host name
+      'transfer-encoding': 'chunked',
+    });
+
+    // Set a host header
+    const result2 = await proxyRequest({
+      agent: null as any,
+      headers: { Host: 'myhost' },
+      method: 'get',
+      payload: null as any,
+      timeout: 30000,
+      uri: new URL('http://noone.nowhere.none'),
+    });
+
+    expect(result2).toEqual('done');
+
+    const [httpRequestOptions2] = stub.secondCall.args;
+    expect((httpRequestOptions2 as any).headers).toEqual({
+      'content-type': 'application/json',
+      Host: 'myhost', // Uses provided host name
+      'transfer-encoding': 'chunked',
+    });
+  });
 });

src/plugins/console/server/lib/proxy_request.ts

@@ -57,19 +57,24 @@ export const proxyRequest = ({
     reject = rej;
   });
 
+  const finalUserHeaders = { ...headers };
+  const hasHostHeader = Object.keys(finalUserHeaders).some(key => key.toLowerCase() === 'host');
+  if (!hasHostHeader) {
+    finalUserHeaders.host = hostname;
+  }
+
   const req = client.request({
     method: method.toUpperCase(),
     // We support overriding this on a per request basis to support legacy proxy config. See ./proxy_config.
     rejectUnauthorized: typeof rejectUnauthorized === 'boolean' ? rejectUnauthorized : undefined,
     host: hostname,
-    port: port === '' ? undefined : Number(port),
+    port: port === '' ? undefined : parseInt(port, 10),
     protocol,
     path: `${pathname}${search || ''}`,
     headers: {
-      ...headers,
+      ...finalUserHeaders,
       'content-type': 'application/json',
       'transfer-encoding': 'chunked',
-      host: hostname,
     },
     agent,
   });