Add local testing feature with RIE

Author: AntoniaSzecsi

.dockerignore

@@ -0,0 +1,9 @@
+target/debug
+target/*/debug
+.git
+.github
+examples
+lambda-integration-tests
+*.md
+.gitignore
+.rustfmt.toml

Cargo.toml

@@ -9,7 +9,7 @@ members = [
     "lambda-events",
 ]
 
-exclude = ["examples"]
+exclude = ["examples", "test-handler"]
 
 [workspace.dependencies]
 base64 = "0.22"

Dockerfile.rie

@@ -0,0 +1,16 @@
+FROM public.ecr.aws/lambda/provided:al2023
+
+RUN dnf install -y gcc
+RUN curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh -s -- -y
+ENV PATH="/root/.cargo/bin:${PATH}"
+
+ADD https://github.com/aws/aws-lambda-runtime-interface-emulator/releases/latest/download/aws-lambda-rie /usr/local/bin/aws-lambda-rie
+RUN chmod +x /usr/local/bin/aws-lambda-rie
+
+COPY . /build
+WORKDIR /build/test-handler
+RUN cargo build --release
+RUN cp target/release/test-handler ${LAMBDA_RUNTIME_DIR}/bootstrap
+
+ENTRYPOINT []
+CMD [ "/usr/local/bin/aws-lambda-rie", "/var/runtime/bootstrap" ]

Makefile

@@ -108,4 +108,7 @@ check-event-features:
 	cargo test --package aws_lambda_events --no-default-features --features streams
 
 fmt:
-	cargo +nightly fmt --all
+	cargo +nightly fmt --all
+
+test-rie:
+	./scripts/test-rie.sh

README.md

@@ -392,6 +392,30 @@ curl -v -X POST \
 
 You can read more about how [cargo lambda watch](https://www.cargo-lambda.info/commands/watch.html) and [cargo lambda invoke](https://www.cargo-lambda.info/commands/invoke.html) work on the project's [documentation page](https://www.cargo-lambda.info).
 
+### Local testing with Runtime Interface Emulator (RIE)
+
+For testing with the official AWS Lambda Runtime Interface Emulator, use the provided RIE testing infrastructure:
+
+```bash
+make test-rie
+```
+
+This command will:
+1. Build a Docker image with Rust toolchain and RIE
+2. Compile the test handler inside the Linux container
+3. Start the RIE container on port 9000
+4. Display the curl command to test your function
+
+Once running, test the function from another terminal:
+
+```bash
+curl -XPOST 'http://localhost:9000/2015-03-31/functions/function/invocations' \
+  -d '{"command": "test from RIE"}' \
+  -H 'Content-Type: application/json'
+```
+
+This provides automated testing with Docker and RIE, ensuring your Lambda functions work in a Linux environment identical to AWS Lambda.
+
 ### Lambda Debug Proxy
 
 Lambdas can be run and debugged locally using a special [Lambda debug proxy](https://github.com/rimutaka/lambda-debug-proxy) (a non-AWS repo maintained by @rimutaka), which is a Lambda function that forwards incoming requests to one AWS SQS queue and reads responses from another queue. A local proxy running on your development computer reads the queue, calls your Lambda locally and sends back the response. This approach allows debugging of Lambda functions locally while being part of your AWS workflow. The Lambda handler code does not need to be modified between the local and AWS versions.

scripts/test-rie.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+set -euo pipefail
+
+echo "Building Docker image with RIE..."
+docker build -f Dockerfile.rie -t rust-lambda-rie-test .
+
+echo "Starting RIE container on port 9000..."
+docker run -p 9000:8080 rust-lambda-rie-test
+
+echo "Container started. Test with:"
+echo "curl -XPOST 'http://localhost:9000/2015-03-31/functions/function/invocations' -d '{\"command\": \"test from RIE\"}' -H 'Content-Type: application/json'"
+echo ""
+echo "Press Ctrl+C to stop the container."

test-handler/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "test-handler"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+lambda_runtime = { path = "../lambda-runtime" }
+serde = "1.0"
+tokio = { version = "1", features = ["macros"] }

test-handler/src/main.rs

@@ -0,0 +1,30 @@
+use lambda_runtime::{service_fn, tracing, Error, LambdaEvent};
+use serde::{Deserialize, Serialize};
+
+#[derive(Deserialize)]
+struct Request {
+    command: String,
+}
+
+#[derive(Serialize)]
+struct Response {
+    message: String,
+    status: String,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Error> {
+    tracing::init_default_subscriber();
+    let func = service_fn(handler);
+    lambda_runtime::run(func).await?;
+    Ok(())
+}
+
+async fn handler(event: LambdaEvent<Request>) -> Result<Response, Error> {
+    let command = event.payload.command;
+    
+    Ok(Response {
+        message: format!("Echo: {}", command),
+        status: "success".to_string(),
+    })
+}