Luna  Hermann

Luna Hermann

1594377780

Calling an AWS Lambda function from another Lambda function

In this article, I am going to explain how to create an AWS Lambda function and then call this function from another Lambda function within the same region. This is a useful scenario in which we may need to execute a second lambda function based on the outcome of some previous logic. Another scenario may be to execute a second lambda function several times by using different parameters.

For the sake of this article, we will consider a typical retailer application, in which we can purchase different products from a retailer site using a lambda function.

Architecture Diagram

Figure 1 – Architecture Diagram

If you consider the above architecture diagram, you can see that we have an AWS lambda function – the ParentFunction, which assumes a specific role from the IAM (Invoke Other Lambda Function) and then calls another lambda function – the ChildFunction with a payload. Once the execution of the ChildFunction is completed, it returns a response, which is then passed on to the ParentFunction. The ParentFunction receives the response and handles the job accordingly.

As in this example, let us assume that the ParentFunction is going to call the ChildFunction with a payload of ProductName, Quantity, and the UnitPrice of that product. The ChildFunction, in turn, will process this payload, calculate the total sales amount, generate a transaction reference ID, and return this information to the ParentFunction.

Creating the first AWS Lambda Function – ChildFunction

Let us first go ahead and create the ChildFunction, which will process the input payload and return the results to the ParentFunction.

#aws rds #functions #aws #lambda function

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Calling an AWS Lambda function from another Lambda function
Luna  Hermann

Luna Hermann

1594377780

Calling an AWS Lambda function from another Lambda function

In this article, I am going to explain how to create an AWS Lambda function and then call this function from another Lambda function within the same region. This is a useful scenario in which we may need to execute a second lambda function based on the outcome of some previous logic. Another scenario may be to execute a second lambda function several times by using different parameters.

For the sake of this article, we will consider a typical retailer application, in which we can purchase different products from a retailer site using a lambda function.

Architecture Diagram

Figure 1 – Architecture Diagram

If you consider the above architecture diagram, you can see that we have an AWS lambda function – the ParentFunction, which assumes a specific role from the IAM (Invoke Other Lambda Function) and then calls another lambda function – the ChildFunction with a payload. Once the execution of the ChildFunction is completed, it returns a response, which is then passed on to the ParentFunction. The ParentFunction receives the response and handles the job accordingly.

As in this example, let us assume that the ParentFunction is going to call the ChildFunction with a payload of ProductName, Quantity, and the UnitPrice of that product. The ChildFunction, in turn, will process this payload, calculate the total sales amount, generate a transaction reference ID, and return this information to the ParentFunction.

Creating the first AWS Lambda Function – ChildFunction

Let us first go ahead and create the ChildFunction, which will process the input payload and return the results to the ParentFunction.

#aws rds #functions #aws #lambda function

Ray  Patel

Ray Patel

1619510796

Lambda, Map, Filter functions in python

Welcome to my Blog, In this article, we will learn python lambda function, Map function, and filter function.

Lambda function in python: Lambda is a one line anonymous function and lambda takes any number of arguments but can only have one expression and python lambda syntax is

Syntax: x = lambda arguments : expression

Now i will show you some python lambda function examples:

#python #anonymous function python #filter function in python #lambda #lambda python 3 #map python #python filter #python filter lambda #python lambda #python lambda examples #python map

Valerio Tana

Valerio Tana

1594821831

Invoke AWS Lambda with Another Lambda Function with Nodejs

In this article, I will show you how to invoke a lambda function from another lambda function.

This invocation is most helpful in scenarios where you have layers or have common inputs to two functions, but they can’t be integrated, in such cases, we use the invoke method. Well, this is just one of the reasons, there are infinitely many reasons to use this based on your requirement.

For this, I have created two functions, **triggerLambdaFunction **and testFunction. While creating a Lambda function make sure you assign the IAM Role for Lambda, which has Policies of “AWSLambdaFullAccess” attached to it as shown below.

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IAM Role to be used in lambda functions

The “testFunction” is the one we are going to trigger using another lambda function called “triggerLambdaFunction”. Both are created in the same way and here I’m using Node.js to write the functions.

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Creating a new Lambda Function

In this triggerLambdaFunction, we have a FunctionCode window where we write our code to invoke another function using AWSLambda-invoke method which is defined in AWS.Lambda-class. So to use this method we should first import our AWS-SDK in the function. This is done to provide JavaScript objects for our AWS service.

#nodejs #lambda #aws #aws-lambda

Cross-account access to invoke AWS lambda using AWS CDK

If you are here, you may have a pretty good knowledge of how to use AWS CDK for defining cloud infrastructure in code and provisioning it through AWS. So let’s get started on how to grant permission to your lambda function to access the resources in another AWS account.

Let’s say you have two accounts called Account A and Account B, and you need to give permission to lambda function in Account A (ex: 11111111)to access the resources in Account B(22222222). You can easily do this by assuming an IAM Role in Account B and then uses the returned credentials to invoke AWS resources in Account B.

#acces #account #aws #lambda #aws lambda #aws cdk

Cache secrets using AWS Lambda extensions

What is the AWS Lambda extension?

A month back AWS announced a preview of Lambda Extensions, a new way to easily integrate Lambda with your favorite monitoring, observability, security, and governance tools. Extensions can be published as Lambda layers, there are two types are extension:

  • Internal extensions → Run as part of the runtime process, in-process with your code. Internal extensions enable use cases such as automatically instrumenting code.
  • External extensions → Allow you to run separate processes from the runtime but still within the same execution environment as the Lambda function. External extensions can start before the runtime process and can continue after the runtime shuts down. These extensions run as companion processes to Lambda functions.

#aws #aws-secrets-manager #lambda #aws lambda