Tencentcloud-Serverless-Nodejs SDK Overview

Tencentcloud-Serverless-Nodejs is a Tencent Cloud SCF SDK that integrates SCF business flow APIs to simplify the function invocation method. It can be used to invoke a function quickly from a local system, CVM instance, container, or function, eliminating the need for you to encapsulate public TencentCloud APIs.

Features

Tencentcloud-Serverless-Nodejs SDK has the following features:

• It can invoke functions in a high-performance, low-latency manner.
• It enables quick invocation across functions after the required parameters are entered (by default, it will obtain parameters in environment variables such as region and secretId).
• It supports access with private network domain names.
• It supports session keep-alive.
• It supports cross-region function invocation.

Quick Start

Preparations for development

• Development environment
  Node.js 8.9 and higher.
• Operating environment
  Windows, Linux, or macOS with Tencentcloud-Serverless-Nodejs SDK installed.
• We recommend you use the Serverless Framework CLI to quickly deploy local functions.

Tencentcloud-Serverless-Nodejs SDK installation

Installing via npm (recommended)

1. Select the directory path according to your actual needs and create a directory under it.
   For example, you can create a project directory named testNodejsSDK in the /Users/xxx/Desktop/testNodejsSDK path.
2. Enter the testNodejsSDK directory and run the following commands in sequence to install the Tencentcloud-Serverless-Nodejs SDK.

   npm init -y
   npm install tencentcloud-serverless-nodejs

   After installation, you will be able to see node_modules, package.json, and package-lock.json in the testNodejsSDK directory.

Installing via the source package

Go to the GitHub code hosting page to download the latest source package and install it after decompression.

Using SCF to install dependencies online

To install dependencies online with SCF, run the following command in package.json:

{
    "dependencies": {
    "tencentcloud-serverless-nodejs":"*"
  }
}

Mutual function invocation

Sample

Note：

• To make functions in different regions invoke each other, the regions must be specified. For naming conventions, please see the Region List in Common Parameters.
• If no region is specified, intra-region mutual function invocation will be used by default.
• If no namespace is specified, default will be used by default.
• The invoker function should have the public network access enabled.
• If parameters such as secretId and secretKey are not manually passed in, the function needs to be bound to a role with SCF Invoke permissions (or containing SCF Invoke, such as SCF FullAccess). For more information, please see Roles and Policies.

1. Create a to-be-invoked Node.js function named "FuncInvoked" in the region of Beijing. The content of the function is as follows:

   'use strict';
   exports.main_handler = async (event, context, callback) => {
      console.log("\n Hello World from the function being invoked\n")
      console.log(event)
      console.log(event["non-exist"])
      return event
   };

2. Create an index.js file in the testNodejsSDK directory and enter the following sample code to create an invoking Node.js function.

   const { SDK, LogType }  = require('tencentcloud-serverless-nodejs')
   exports.main_handler = async (event, context) => {
   context.callbackWaitsForEmptyEventLoop = false
   const sdk = new SDK({
    region:'ap-beijing'
   }) // If you bind and run in SCF an execution role with SCF invocation permissions, the authentication information in the environment variable will be used by default
   const res = await sdk.invoke({
    functionName: 'FuncInvoked',
    logType: LogType.Tail,
    data: {
      name: 'test',
      role: 'test_role'
    }
   })
   console.log(res)
   // return res
   }

   The main parameters can be obtained as described below:
   • region: the region of the invoked function. The Beijing region selected in step 1 is used as an example in this document.
   • functionName: the name of the invoked function. The FuncInvoked function created in step 1 is used as an example in this document.
   • qualifier: the version of the invoked function. If no version is specified, $LATEST will be used by default. For more information, please see Viewing a Version.
   • namespace: the namespace of the invoked function. If no namespace is specified, default will be used by default.
   • data: the data passed to the invoked function, which can be read from the event input parameter.
3. Create an invoking Node.js function named "NodejsInvokeTest" in the Chengdu region. The main settings of the function are as follows:
   • Execution method: select index.main_handler.
   • Code submission method: select Local ZIP file.
     Compress all files in the testNodejsSDK directory in ZIP format and upload it to the cloud.
4. On the function details page in the SCF console, you can test run a function by going to the function code tab and clicking Execute. Below is the output result:

   "Already invoked a function!"

Invoking a function locally

Sample

1. Create a to-be-invoked Node.js function named FuncInvoked in the Beijing region. The content of the function is as follows:

   'use strict';
   exports.main_handler = async (event, context, callback) => {
      console.log("\n Hello World from the function being invoked\n")
      console.log(event)
      console.log(event["non-exist"])
      return event
   };

2. Create an index.js file in the testNodejsSDK directory as an invoking Node.js function and enter the following sample code:

   const { SDK, LogType }  = require('tencentcloud-serverless-nodejs')
   exports.main_handler = async (event, context) => {
   context.callbackWaitsForEmptyEventLoop = false
   const sdk = new SDK({
    region:'ap-beijing',
    secretId: 'AKxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxj',
    secretKey: 'WtxxxxxxxxxxxxxxxxxxxxxxxxxxxxqL'
   }) // If you bind and run in SCF an execution role with SCF invocation permissions, the authentication information in the environment variable will be used by default
   const res = await sdk.invoke({
    functionName: 'FuncInvoked',
    logType: LogType.Tail,
    data: {
      name: 'test',
      role: 'test_role'
    }
   })
   console.log(res)
   // return res
   }

   Note：

   secretId and secretKey: the secret ID and secret key of the TencentCloud API. You can go to the CAM console and select Access Key > API Keys to get them or create new ones.

3. Go to the directory where the index.js file is located and run the following command to view the result.

   • On Linux or macOS, run the following command:

     export NODE_ENV=development && node index.js

   • On Windows, run the following command:

     set NODE_ENV=development && node index.js

   The output is as follows:

   prepare to invoke a function!
   {"key":"value"}
   Already invoked a function!

API List

API Reference

• Init
• Invoke

Init

We recommend you run the npm init command to initialize the SDK before using it.

Note：

• The region, secretId, and secretKey parameters can be passed in by using the initialization command.
• After the initialization is completed, the initialization configuration can be reused for future API calls.

Parameter information:

Invoke

This API is used to invoke a function. Currently, sync invocation is supported.

Parameter information: