Amazon Web Services Updated DVA-C02 Exam Questions and Answers by lula

Comprehensive Detailed Step by Step Explanation with All AWS Developer References:

When you need to provide an AWS Lambda function access to private resources in a VPC, the most common and straightforward approach is to attach the Lambda function to a VPC via private subnets. Once the Lambda function is associated with the VPC, you need to configure appropriate security groups to control the access to the private resources.

Lambda with VPC Access: Lambda functions can be attached to private subnets in a VPC, allowing them to access resources like RDS, EC2, or internal services within that VPC.

Security Groups: A security group acts as a virtual firewall for the Lambda function, ensuring that it can access only the necessary resources and ports in the VPC.

Alternatives:

Option B involves routing traffic through a VPN, which adds unnecessary complexity and operational overhead compared to simply attaching the Lambda to the VPC.

Option C requires configuring a VPC endpoint and a NAT gateway, which can be complex and costly.

Option D refers to AWS PrivateLink, which is used to access services over private connections, but it's unnecessary in this scenario unless you need a cross-VPC connection.

Lambda functions in a VPC

This solution will meet the requirements by using AWS Serverless Application Model (AWS SAM) templates and gradual deployments to automatically test the Lambda functions. AWS SAM templates are configuration files that define serverless applications and resources such as Lambda functions. Gradual deployments are a feature of AWS SAM that enable deploying new versions of Lambda functions incrementally, shifting traffic gradually, and performing validation tests during deployment. The developer can enable gradual deployments through AWS SAM templates by adding a DeploymentPreference property to each Lambda function resource in the template. The developer can set the deployment preference type to Canary10Percent30Minutes, which means that 10 percent of traffic will be shifted to the new version of the Lambda function for 30 minutes before shifting 100 percent of traffic. The developer can also use hooks to test the deployment, which are custom Lambda functions that run before or after traffic shifting and perform validation tests or rollback actions.