Book Image

AWS Certified Developer - Associate Guide

By : Vipul Tankariya, Bhavin Parmar
Book Image

AWS Certified Developer - Associate Guide

By: Vipul Tankariya, Bhavin Parmar

Overview of this book

AWS Certified Developer - Associate Guide starts with a quick introduction to AWS and the prerequisites to get you started. Then, this book gives you a fair understanding of core AWS services and basic architecture. Next, this book will describe about getting familiar with Identity and Access Management (IAM) along with Virtual private cloud (VPC). Moving ahead you will learn about Elastic Compute cloud (EC2) and handling application traffic with Elastic Load Balancing (ELB). Going ahead you we will talk about Monitoring with CloudWatch, Simple storage service (S3) and Glacier and CloudFront along with other AWS storage options. Next we will take you through AWS DynamoDB – A NoSQL Database Service, Amazon Simple Queue Service (SQS) and CloudFormation Overview. Finally, this book covers understanding Elastic Beanstalk and overview of AWS lambda. At the end of this book, we will cover enough topics, tips and tricks along with mock tests for you to be able to pass the AWS Certified Developer - Associate exam and develop as well as manage your applications on the AWS platform.
Table of Contents (29 chapters)
Title Page
Credits
About the Author
Acknowledgments
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Dedication
Preface
Index

Environment variables


Reusable and efficient code often requires passing dynamic values at runtime. These runtime values may be environment types, file paths, path to store logs, table names, and so on. With the help of environment variables, Lambda functions allow us to pass dynamic values at runtime. As a result, the code becomes reusable without making any changes to it. Environment variables are key-value pairs and these key-values pairs are encrypted/decrypted using the AWS KMS. Key-value pairs can be defined at the time of creating a Lambda function. Externally configured environment variables are also accessible within the Lambda function, using standard APIs supported by the different programming languages. For example, Node.js functions can access environment variables using process.envprocess.env refers to an object in Node.js. In Node.js, process is the global object and env is the sub-object of process, which provides all environment variables.

The rules for naming environment...