AWS Lambda Layers

What are Layers?

Layers allow you to manage code and dependencies separately from the function code. You can include libraries, custom runtimes, or configuration files in layers and then reference them in multiple functions. This helps in reducing redundancy.

• Usage: Layers are useful when you have common libraries, code, or runtime components that you want to share across multiple Lambda functions.
• Creating and Adding Layers:
  • Layers can be created manually or packaged as a ZIP file containing libraries or other code.
  • You can publish layers via the console, CLI, or SDK.
  • You can add up to 5 layers per Lambda function.
• Example: If multiple Lambda functions need the same version of a data-processing library, you can package the library in a layer, so all functions can reference it without duplicating the library in each function.

AWS Lambda Runtimes

• Built-in Runtimes: AWS Lambda supports several pre-configured built-in runtimes that simplify function deployment:
  • Common languages include Node.js, Python, Java, Go, .NET Core, and Ruby.
  • These runtimes come pre-packaged with the necessary execution environment for each language.
  • You can configure your Lambda function to use one of these built-in runtimes when creating it.
• Custom Runtimes:
  • Why Use Custom Runtimes?: If you need to run code in a language not supported by the built-in runtimes, you can create a custom runtime. This gives you full control over the execution environment.
  • How to Create: Custom runtimes require an API that Lambda can use to invoke functions. You’ll need to build the runtime and deploy it alongside your Lambda function.
  • Example: You might use a custom runtime for a specific language or framework, like Rust or a specialized version of Python, that is not officially supported.

Summary:

• Layers: Separate reusable components that can be shared across multiple Lambda functions to reduce redundancy.
• Runtimes: Use built-in environments for common languages or create custom runtimes for unsupported ones, providing flexibility in execution environments.