The lambda-chaos-extension allows you to inject faults into Lambda functions without modifying the function code. Unlike previous chaos implementations that required tight coupling with the Lambda runtime, this extension is runtime-agnostic. It can operate with any runtime that utilizes Amazon Linux 2. Currently, the supported runtimes include:

• Node.js 18
• Node.js 16
• Node.js 14
• Python 3.10
• Python 3.9
• Python 3.8
• Java 17
• Java 11
• Java 8
• .NET 6
• Ruby 3.2
• Ruby 2.7
• provided.al2

The extension can inject two types of faults based on the configuration:

1. Induce latency.
2. Modify function response.

• 🔄 Seamless Integration: Requires no code changes. Simply plug and play!
• 🌐 Universal Compatibility: Completely agnostic to the Lambda runtime. Flexibility at its finest!
• 🚀 Blazing Fast: Written in Rust for peak performance. Zero impact on your Lambda's behavior when turned off, ensuring smooth operations.

Control the extension via environment variables:

• CHAOS_EXTENSION__LAMBDA__ENABLE_LATENCY - Enables latency fault injection. Accepts true or false. Default is false.
• CHAOS_EXTENSION__LAMBDA__LATENCY_VALUE - Specifies the latency duration (in seconds) to introduce. Default is 900 seconds.
• CHAOS_EXTENSION__LAMBDA__LATENCY_PROBABILITY - A probability value between 0 and 1 that determines the likelihood of fault injection. Default is 0.9.

• CHAOS_EXTENSION__RESPONSE__ENABLE_CHANGE_RESPONSE_BODY - Enables response fault injection. Accepts true or false. Default is false.
• CHAOS_EXTENSION__RESPONSE__DEFAULT_RESPONSE - Specifies the response to return in stringified JSON format. Default is:

{
    "statusCode": 500,
    "body": "hello, Chaos!!!"
}

• CHAOS_EXTENSION__RESPONSE__CHANGE_RESPONSE_PROBABILITY - A probability value between 0 and 1 that determines the likelihood of fault injection. Default is 0.9.

The chaos extension is publicly available as a layer. For the latest versions of the layer, refer to LAYERS.md. Incorporate the layer using the AWS Console, or your preferred IAC solution. Additionally, when incorporating the layer, remember to set an environment variable in your Lambda. This variable should be named AWS_LAMBDA_EXEC_WRAPPER and have /opt/bootstrap as its value.

See the AWS SAM usage example in the examples directory.

• Utilize cargo for build and test management.
• We employ just as a command runner.
• Execute just gate to run all checks locally.

• Use just deploy-debug-extension to deploy a debug version of the extension to us-east-1 using x86_64-unknown-linux-gnu as target.
• Use just deploy-release-extension to deploy a release version of the extension to us-east-1 using x86_64-unknown-linux-gnu as target.

These just tasks also accept arguments to change the region and the target. Use just --list to get more details about the various deploy options.

• Use RUST_LOG environment variable to change the extension log level. Default is error.

For contribution guidelines, see our CONTRIBUTION page.