10 Lambda VPC Best Practices
If you're using Lambda, you should be aware of these 10 best practices to get the most out of it.
AWS Lambda is a serverless computing platform that allows developers to run code without having to manage servers. Lambda functions can be deployed in a Virtual Private Cloud (VPC) to provide additional security and control.
However, deploying Lambda functions in a VPC can be tricky and requires careful planning. In this article, we will discuss 10 best practices for deploying Lambda functions in a VPC. We will cover topics such as security, performance, and cost optimization. By following these best practices, you can ensure that your Lambda functions are secure, performant, and cost-effective.
1. Use VPC Endpoints
VPC endpoints allow you to securely access AWS services without having to traverse the public internet. This is especially important for Lambda functions that need to access other AWS services, such as S3 or DynamoDB.
Using VPC endpoints also helps improve performance and reduce latency by eliminating the need to route traffic through a NAT gateway or VPN connection. Additionally, it can help reduce costs since there are no data transfer fees associated with using VPC endpoints. Finally, VPC endpoints provide an additional layer of security since they use private IP addresses instead of public ones.
2. Use the Right Subnets
When you create a lambda function, it needs to be associated with a VPC. This means that the function will need access to resources within the VPC such as databases and other services.
To ensure that your lambda functions have access to the right resources, you should use private subnets for your lambdas. Private subnets are isolated from the public internet, so they provide an extra layer of security. Additionally, using private subnets ensures that your lambdas can only access resources within the VPC, which helps prevent unauthorized access.
3. Configure Security Groups
Security groups are a way to control inbound and outbound traffic from your Lambda functions. By configuring security groups, you can ensure that only the necessary ports and protocols are open for communication with other resources within your VPC. This helps protect against malicious attacks and unauthorized access.
Additionally, it’s important to configure network ACLs (NACLs) as well. NACLs provide an additional layer of security by allowing you to specify which IP addresses or ranges are allowed to communicate with your Lambda functions. Configuring both security groups and NACLs will help keep your Lambda functions secure and running smoothly.
4. Enable X-Ray Tracing
X-Ray tracing allows you to trace requests and responses from your Lambda functions, giving you visibility into the performance of your application. This is especially important when running in a VPC because it can be difficult to troubleshoot issues without this type of visibility.
Enabling X-Ray tracing requires setting up an IAM role with permission to write logs to CloudWatch Logs. Once that’s done, you’ll need to configure your Lambda function to use the role. Finally, you’ll need to enable X-Ray tracing for your Lambda function by adding the necessary environment variables. With these steps complete, you’ll have full visibility into the performance of your Lambda functions running in a VPC.
5. Monitor Lambda Metrics
When Lambda functions are running in a VPC, they can be subject to network latency and other issues that can affect performance. By monitoring metrics such as invocation count, duration, errors, and throttles, you can quickly identify any potential problems with your Lambda functions and take corrective action before they become serious.
You should also monitor the health of your VPCs by keeping an eye on CPU utilization, memory usage, and disk space. This will help ensure that your Lambda functions have enough resources to run efficiently and reliably.
6. Keep Functions Stateless
When you run a Lambda function in a VPC, it needs to be able to access resources within the VPC. This means that each time your function is invoked, it will need to establish a connection with the VPC and then tear down the connection when it’s done. If your functions are stateful, meaning they store data between invocations, this can cause performance issues as the connections must be re-established every time.
By keeping your functions stateless, you ensure that the same amount of time is spent establishing the connection regardless of how many times the function has been invoked. This helps keep your Lambda functions running smoothly and efficiently.
7. Leverage AWS Services for Logging and Monitoring
AWS provides a range of services that can be used to monitor and log your lambda functions. These include CloudWatch Logs, CloudTrail, AWS Config, Amazon Inspector, and more. By leveraging these services, you can ensure that your Lambda functions are running as expected and that any issues are quickly identified and addressed. Additionally, logging and monitoring will help you identify potential security risks or performance bottlenecks in your VPC environment.
8. Use Environment Variables to Store Secrets
When you store secrets in environment variables, they are encrypted and stored securely. This means that even if someone were to gain access to your Lambda function, they would not be able to view the secrets. Additionally, using environment variables makes it easier to manage secrets across multiple functions since you can use the same variable name for each one.
Finally, when you use environment variables, you don’t have to worry about hard-coding secrets into your code. This helps keep your code clean and secure, as well as making it easier to maintain.
9. Avoid Using Lambda Layers for Libraries
Lambda layers are static and can’t be updated without redeploying the entire layer. This means that if a library is updated, you’ll need to update your Lambda layer as well, which can be time consuming and difficult to manage.
Instead of using Lambda layers for libraries, it’s best practice to package them with your code when deploying to Lambda VPCs. This way, you can easily update your libraries whenever necessary without having to worry about updating the Lambda layer. Additionally, this will help keep your Lambda functions more secure since they won’t have access to outdated libraries.
10. Use CloudWatch Alarms for Notifications
CloudWatch Alarms allow you to set up notifications for when certain conditions are met, such as when a Lambda function is running too long or if it’s using too much memory. This allows you to quickly identify and address any issues that may arise with your Lambda functions in the VPC. Additionally, CloudWatch Alarms can be used to monitor other aspects of your AWS environment, such as EC2 instances, S3 buckets, and more.
