Fix prefix static source 404 issue (#4051)

ts/nni_manager/common/experimentStartupInfo.ts

@@ -126,3 +126,8 @@ export function getDispatcherPipe(): string | null {
 export function getAPIRootUrl(): string {
     return getExperimentStartupInfo().apiRootUrl;
 }
+
+export function getPrefixUrl(): string {
+    const prefix = getExperimentStartupInfo().urlprefix === '' ? '' : `/${getExperimentStartupInfo().urlprefix}`;
+    return prefix;
+}

ts/nni_manager/rest_server/nniRestServer.ts

@@ -11,7 +11,7 @@ import * as component from '../common/component';
 import { RestServer } from '../common/restServer'
 import { getLogDir } from '../common/utils';
 import { createRestHandler } from './restHandler';
-import { getAPIRootUrl } from '../common/experimentStartupInfo';
+import { getAPIRootUrl, getPrefixUrl } from '../common/experimentStartupInfo';
 
 /**
  * NNI Main rest server, provides rest API to support
@@ -38,7 +38,7 @@ export class NNIRestServer extends RestServer {
      * NNIRestServer's own router registration
      */
     protected registerRestHandler(): void {
-        this.app.use(express.static('static'));
+        this.app.use(getPrefixUrl(), express.static('static'));
         this.app.use(bodyParser.json({limit: '50mb'}));
         this.app.use(this.API_ROOT_URL, createRestHandler(this));
         this.app.use(this.LOGS_ROOT_URL, express.static(getLogDir()));
@@ -50,7 +50,7 @@ export class NNIRestServer extends RestServer {
                 target: 'https://netron.app'
             });
         });
-        this.app.get('*', (req: express.Request, res: express.Response) => {
+        this.app.get(`${getPrefixUrl()}/*`, (req: express.Request, res: express.Response) => {
             res.sendFile(path.resolve('static/index.html'));
         });
     }

ts/webui/src/static/function.ts

@@ -14,7 +14,13 @@ function getPrefix(): string | undefined {
             newPathName = pathName.replace(item, '');
         }
     });
-    return newPathName === '' || newPathName === '/' ? undefined : newPathName;
+    let result = newPathName === '' || newPathName === '/' ? undefined : newPathName;
+    if (result !== undefined) {
+        if (result.endsWith('/')) {
+            result = result.slice(0, result.length - 1);
+        }
+    }
+    return result;
 }
 
 async function requestAxios(url: string): Promise<any> {