tencent cloud

Tencentcloud-Serverless-Nodejs SDK Overview

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

Features

Tencentcloud-Serverless-Nodejs SDK has the following features:

• Invokes 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).
• Supports access with private network domain names.
• Supports session keep-alive.
• Supports cross-region function chaining.

Note：

Calling SDK across functions is only applicable to event-triggered functions. HTTP-triggered functions can be invoked by requesting the corresponding path of the function in the function code.

Getting Started

Development Preparations

• Development environment
  Node.js 8.9 or a higher version has been installed.
• Running environment
  Windows, Linux, or macOS with tencentcloud-serverless-nodejs SDK have been installed.
• We recommend you use the Serverless Cloud Framework to quickly deploy local functions.

Installing the tencentcloud-serverless-nodejs SDK

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 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 Recursion

Sample

Note：

• To implement mutual recursion of functions in different regions, you need to specify the region. For the naming rules, please see Region List.
• If no region is specified, functions will invoke one another within the same region.
• 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 package upload.
  Compress all files in the testNodejsSDK directory to ZIP format and upload them to the cloud.

4. In the SCF console, click the function just created, go to Function management > Edit codes. Click Test to run the function. The result should be as follows:

   "Already invoked a function!"
   

Invoking a function locally

Sample

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 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: Secret ID and secret key of TencentCloud API. You can obtain them or create new ones by logging into the CAM Console and selecting Access Key > API Key Management.

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 using the initialization command.
• After the initialization is completed, the initialization configuration can be reused for future API calls.

Parameter information:

Parameter Name	Required	Type	Description
region	No	String	Region
secretId	No	String	process.env.TENCENTCLOUD_SECRETID is used by default
secretKey	No	String	process.env.TENCENTCLOUD_SECRETKEY is used by default
token	No	String	process.env.TENCENTCLOUD_SESSIONTOKEN is used by default

Invoke

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

Parameter information:

Parameter Name	Required	Type	Description
functionName	Yes	String	Function name
qualifier	No	String	Function version. Default value: $LATEST
data	No	String	Input parameter for function execution
namespace	No	String	Namespace, which is default by default.
region	No	String	Region
secretId	No	String	process.env.TENCENTCLOUD_SECRETID is used by default
secretKey	No	String	process.env.TENCENTCLOUD_SECRETKEY is used by default
token	No	String	process.env.TENCENTCLOUD_SESSIONTOKEN is used by default