attu/server/src/app.ts

import express from 'express';
import cors from 'cors';
import helmet from 'helmet';
import * as http from 'http';
import { Server, Socket } from 'socket.io';
import { router as connectRouter } from './milvus';
import { router as collectionsRouter } from './collections';
import { router as partitionsRouter } from './partitions';
import { router as schemaRouter } from './schema';
import { router as cronsRouter } from './crons';
import { router as userRouter } from './users';

import { pubSub } from './events';
import {
  TransformResMiddlerware,
  LoggingMiddleware,
  ErrorMiddleware,
  ReqHeaderMiddleware,
} from './middlewares';

import { getDirectories, getDirectoriesSync, generateCfgs } from './utils';
import * as path from 'path';
import chalk from 'chalk';
import { surveSwaggerSpecification } from './swagger';
import swaggerUi from 'swagger-ui-express';
import LruCache from 'lru-cache';
import { EXPIRED_TIME, INSIGHT_CACHE } from './utils/Const';

const PLUGIN_DEV = process.env?.PLUGIN_DEV;
const SRC_PLUGIN_DIR = 'src/plugins';
const DEV_PLUGIN_DIR = '../../src/*/server';

const insightCache = new LruCache({
  maxAge: EXPIRED_TIME,
  updateAgeOnGet: true,
});

export const app = express();
const PORT = 3000;
// initialize a simple http server
const server = http.createServer(app);
// initialize the WebSocket server instance
const io = new Server(server, {
  cors: {
    origin: '*',
    methods: ['GET', 'POST'],
  },
});

app.set(INSIGHT_CACHE, insightCache);
// https://expressjs.com/en/resources/middleware/cors.html
app.use(cors());
// https://github.com/helmetjs/helmet
app.use(
  helmet({
    contentSecurityPolicy: false,
  })
);
app.use(express.json({ limit: '150MB' }));
// TransformResInterceptor
app.use(TransformResMiddlerware);
// LoggingInterceptor
app.use(LoggingMiddleware);

// All headers operations
app.use(ReqHeaderMiddleware);

const router = express.Router();
const pluginsRouter = express.Router();

// Init WebSocket server event listener
io.on('connection', (socket: Socket) => {
  console.log('socket.io connected');
  socket.on('COLLECTION', (message: any) => {
    socket.emit('COLLECTION', { data: message });
  });
  pubSub.on('ws_pubsub', msg => {
    const { event, data } = msg;
    socket.emit(event, data);
  });
});

// Read plugin files and start express server
// Import all plguins under "src/plugins"
getDirectories(SRC_PLUGIN_DIR, async (dirErr: Error, dirRes: string[]) => {
  const cfgs: any[] = [];
  if (dirErr) {
    console.log('Reading plugin directory Error', dirErr);
  } else {
    generateCfgs(cfgs, dirRes);
  }
  // If under plugin dev mode, import all plugins under "../../src/*/server"
  if (PLUGIN_DEV) {
    getDirectoriesSync(
      DEV_PLUGIN_DIR,
      (devDirErr: Error, devDirRes: string[]) => {
        if (devDirErr) {
          console.log('Reading dev plugin directory Error', devDirErr);
        } else {
          generateCfgs(cfgs, devDirRes, false);
        }
      }
    );
  }
  console.log('======/api/plugins configs======', cfgs);
  cfgs.forEach(async (cfg: any) => {
    const { api: pluginPath, componentPath } = cfg;
    if (!pluginPath) return;
    const {
      default: { router: pluginRouter },
    } = await import(componentPath);
    pluginsRouter.use(`/${pluginPath}`, pluginRouter);
  });

  router.use('/milvus', connectRouter);
  router.use('/collections', collectionsRouter);
  router.use('/partitions', partitionsRouter);
  router.use('/schema', schemaRouter);
  router.use('/crons', cronsRouter);
  router.use('/users', userRouter);

  router.get('/healthy', (req, res, next) => {
    res.json({ status: 200 });
    next();
  });

  app.use('/api/v1', router);
  app.use('/api/plugins', pluginsRouter);

  // Return client build files
  app.use(express.static('build'));

  const data = surveSwaggerSpecification();
  app.use('/api/v1/swagger', swaggerUi.serve, swaggerUi.setup(data));

  // handle every other route with index.html, which will contain
  // a script tag to your application's JavaScript file(s).
  app.get('*', (request, response) => {
    response.sendFile(path.join(__dirname, '../build/index.html'));
  });

  // ErrorInterceptor
  app.use(ErrorMiddleware);
  // start server
  server.listen(PORT, () => {
    console.log(chalk.green.bold(`Attu Server started on port ${PORT} :)`));
  });
});