Deploying Express.js Application

Last updated: 2021-01-15 15:56:22


    Tencent Cloud Express component uses Tencent Serverless Framework. Based on serverless services (gateways, functions, etc.) in the cloud, it can implement "zero" configuration, convenient development, and rapid deployment of your Express application. The Express component supports a rich set of configuration extensions and provides the easiest-to-use, low-cost, and elastically scalable cloud-based Express project development and hosting capabilities.

    Express.js features:

    • Pay-as-you-go billing: fees are charged based on the request usage, and you don't need to pay anything if there is no request.
    • "Zero" configuration: you only need to write project code and then deploy it, and the Serverless Framework will take care of all the configuration work.
    • Fast deployment: you can deploy your entire Express application in just a few seconds.
    • Real-time log: you can view the business status through the output of the real-time log, which makes it easy for you to develop applications directly in the cloud.
    • Cloud debugging: it supports quick cloud debugging for the Node.js framework, which shields differences in the local environment.
    • Convenient collaboration: the status information and deployment logs in the cloud make multi-person collaborative development easier.
    • Custom domain name: it supports configuration of custom domain names and HTTPS access.

    Through the Serverless Framework Express component, you can quickly migrate traditional local Express applications to the serverless function platform.

    Migration Prerequisites


    If your account is a Tencent Cloud sub-account, please get the authorization from the root account first as instructed in Account and Permission Configuration.


    The Express component will use the following Serverless services in your Tencent Cloud account:

    • API Gateway: it will receive external requests and forward them to the SCF function.
    • SCF: it will carry the Express application.
    • CAM: this component will create a default CAM role for authorizing access to associated resources.
    • COS: to ensure the upload speed and quality, when the function is compressed and the code is uploaded, the code package will be stored in a specifically named COS bucket by default.



    The following steps are mainly for deployment on the command line. For deployment in the console, please see Console Deployment Guide.

    1. Initialize the Express template project (optional)

    If you don't have a local Express project, you can quickly create an Express project template with the following command (if you already have one, you can ignore this step):

    serverless init express-starter --name example
    cd example

    2. Modify the project code

    Open the entry file sls.js (or app.js) of the Express project, comment out the local listening port, and export the default Express application:

    // sls.js
    const express = require('express');
    const app = express();
    // *****
    // Comment out the local listening port
    // app.listen(3000);
    // Export the Express application
    module.exports = app;

    3. Generate a .yml file and deploy

    After modifying the code, you can run the sls deploy command, and Serverless Framework will automatically generate a basic serverless.yml file and complete the deployment to quickly migrate the Express framework application.

    The generated default configuration file is as follows:

    component: express
    name: expressDemo
    app: appDemo
      entryFile: sls.js # Use the actual entry file name
      src: ./
      region: ap-guangzhou
      runtime: Nodejs10.15
          - http
          - https
        environment: release

    After the deployment is completed, access the application by accessing the output API Gateway link.

    4. Modify the .yml configuration file

    You can add more configuration items in serverless.yml based on your actual deployment needs and run sls deploy for redeployment.

    For more information on the configuration of the .yml file, please see Express Component Configuration.

    5. Monitor the OPS

    After the deployment is completed, you can log in to the Serverless Framework console to view the basic information of the application and monitor logs.

    Account Configuration

    Currently, you can scan a QR code to log in to the CLI by default. If you want to configure persistent environment variables/key information, you can also create a local .env file:

    $ touch .env # Tencent Cloud configuration information

    Configure Tencent Cloud's SecretId and SecretKey information in the .env file and save it:

    # .env


    • If you don't have a Tencent Cloud account yet, please sign up first.
    • If you already have a Tencent Cloud account, you can get SecretId and SecretKey in API Key Management.