The Rust code is an experimental package to extract procrate file on AWS lambda. It is subject to change and intended only for evaluation purposes.
The preferred way to install Cargo Lambda is by using a package manager.
Use Homebrew on MacOS:
brew tap cargo-lambda/cargo-lambda
brew install cargo-lambda
See other installation options in the Cargo Lambda documentation.
If you already have Cargo Lambda installed in your machine, run the next command to build your function:
cargo lambda build --release
There are other ways of building your function: manually with the AWS CLI, with AWS SAM, and with the Serverless framework.
By default, Cargo Lambda builds your functions to run on x86_64 architectures. If you'd like to use a different architecture, use the options described below.
Amazon Linux 2
We recommend you to use Amazon Linux 2 runtimes (such as provided.al2
) as much as possible for building Lambda functions in Rust. To build your Lambda functions for Amazon Linux 2 runtimes, run:
cargo lambda build --release --arm64
Amazon Linux 1
Amazon Linux 1 uses glibc version 2.17, while Rust binaries need glibc version 2.18 or later by default. However, with Cargo Lambda, you can specify a different version of glibc.
If you are building for Amazon Linux 1, or you want to support both Amazon Linux 2 and 1, run:
cargo lambda build --release --target aarch64-unknown-linux-gnu.2.17
Note Replace "aarch64" with "x86_64" if you are building for x86_64
For a custom runtime, AWS Lambda looks for an executable called bootstrap
in the deployment package zip. Rename the generated executable to bootstrap
and add it to a zip archive.
You can find the bootstrap
binary for your function under the target/lambda
directory.
Once you've built your code with one of the options described earlier, use the deploy
subcommand to upload your function to AWS:
cargo lambda deploy \
--iam-role arn:aws:iam::XXXXXXXXXXXXX:role/your_lambda_execution_role
Warning Make sure to replace the execution role with an existing role in your account!
This command will create a Lambda function with the same name of your rust package. You can change the name of the function by adding the argument at the end of the command:
cargo lambda deploy \
--iam-role arn:aws:iam::XXXXXXXXXXXXX:role/your_lambda_execution_role \
my-first-lambda-function
Note See other deployment options in the Cargo Lambda documentation.
You can test the function with the invoke subcommand:
cargo lambda invoke --remote \
--data-ascii '{"command": "hi"}' \
--output-format json \
my-first-lambda-function
Note CLI commands in the examples use Linux/MacOS syntax. For different shells like Windows CMD or PowerShell, modify syntax when using nested quotation marks like
'{"command": "hi"}'
. Escaping with a backslash may be necessary. See AWS CLI Reference for more information.
You can also use the AWS CLI to deploy your Rust functions. First, you will need to create a ZIP archive of your function. Cargo Lambda can do that for you automatically when it builds your binary if you add the output-format
flag:
cargo lambda build --release --arm64 --output-format zip
You can find the resulting zip file in target/lambda/YOUR_PACKAGE/bootstrap.zip
. Use that file path to deploy your function with the AWS CLI:
$ aws lambda create-function --function-name rustTest \
--handler bootstrap \
--zip-file fileb://./target/lambda/basic/bootstrap.zip \
--runtime provided.al2023 \ # Change this to provided.al2 if you would like to use Amazon Linux 2 (or to provided.al for Amazon Linux 1).
--role arn:aws:iam::XXXXXXXXXXXXX:role/your_lambda_execution_role \
--environment Variables={RUST_BACKTRACE=1} \
--tracing-config Mode=Active
Warning Make sure to replace the execution role with an existing role in your account!
You can now test the function using the AWS CLI or the AWS Lambda console
$ aws lambda invoke
--cli-binary-format raw-in-base64-out \
--function-name rustTest \
--payload '{"command": "Say Hi!"}' \
output.json
$ cat output.json # Prints: {"msg": "Command Say Hi! executed."}
Note
--cli-binary-format raw-in-base64-out
is a required argument when using the AWS CLI version 2. More Information
You can use Lambda functions built in Rust with the AWS Serverless Application Model (SAM). To do so, you will need to install the AWS SAM CLI, which will help you package and deploy your Lambda functions in your AWS account.
You will need to create a template.yaml
file containing your desired infrastructure in YAML. Here is an example with a single Lambda function:
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
HelloWorldFunction:
Type: AWS::Serverless::Function
Properties:
MemorySize: 128
Architectures: ["arm64"]
Handler: bootstrap
Runtime: provided.al2023
Timeout: 5
CodeUri: target/lambda/basic/
Outputs:
FunctionName:
Value: !Ref HelloWorldFunction
Description: Name of the Lambda function
You can then deploy your Lambda function using the AWS SAM CLI:
sam deploy --guided
At the end, sam
will output the actual Lambda function name. You can use this name to invoke your function:
$ aws lambda invoke
--cli-binary-format raw-in-base64-out \
--function-name HelloWorldFunction-XXXXXXXX \ # Replace with the actual function name
--payload '{"command": "Say Hi!"}' \
output.json
$ cat output.json # Prints: {"msg": "Command Say Hi! executed."}
Alternatively, you can build a Rust-based Lambda function declaratively using the Serverless framework Rust plugin.
A number of getting started Serverless application templates exist to get you up and running quickly:
- a minimal echo function to demonstrate what the smallest Rust function setup looks like
- a minimal http function to demonstrate how to interface with API Gateway using Rust's native http crate (note this will be a git dependency until 0.2 is published)
- a combination multi function service to demonstrate how to set up a services with multiple independent functions
Assuming your host machine has a relatively recent version of node, you won't need to install any host-wide serverless dependencies. To get started, run the following commands to create a new lambda Rust application and install project level dependencies.
$ npx serverless install \
--url https://github.com/softprops/serverless-aws-rust \
--name my-new-app \
&& cd my-new-app \
&& npm install --silent
Deploy it using the standard serverless workflow:
# build, package, and deploy service to aws lambda
$ npx serverless deploy
Invoke it using serverless framework or a configured AWS integrated trigger source:
npx serverless invoke -f hello -d '{"foo":"bar"}'
Alternatively, you can build a Rust-based Lambda function in a docker mirror of the AWS Lambda provided runtime with the Rust toolchain preinstalled.
Running the following command will start an ephemeral docker container, which will build your Rust application and produce a zip file containing its binary auto-renamed to bootstrap
to meet the AWS Lambda's expectations for binaries under target/lambda_runtime/release/{your-binary-name}.zip
. Typically, this is just the name of your crate if you are using the cargo default binary (i.e. main.rs
):
# build and package deploy-ready artifact
$ docker run --rm \
-v ${PWD}:/code \
-v ${HOME}/.cargo/registry:/root/.cargo/registry \
-v ${HOME}/.cargo/git:/root/.cargo/git \
rustserverless/lambda-rust
With your application built and packaged, it's ready to ship to production. You can also invoke it locally to verify is behavior using the lambci :provided docker container, which is also a mirror of the AWS Lambda provided runtime with build dependencies omitted:
# start a docker container replicating the "provided" lambda runtime
# awaiting an event to be provided via stdin
$ unzip -o \
target/lambda/release/{your-binary-name}.zip \
-d /tmp/lambda && \
docker run \
-i -e DOCKER_LAMBDA_USE_STDIN=1 \
--rm \
-v /tmp/lambda:/var/task \
lambci/lambda:provided
# provide an event payload via stdin (typically a json blob)
# Ctrl-D to yield control back to your function
AWS Lambda events are plain structures deserialized from JSON objects.
If your function handler uses the standard runtime, you can use serde
to deserialize
your text fixtures into the structures, and call your handler directly:
#[test]
fn test_my_lambda_handler() {
let input = serde_json::from_str("{\"command\": \"Say Hi!\"}").expect("failed to parse event");
let context = lambda_runtime::Context::default();
let event = lambda_runtime::LambdaEvent::new(input, context);
my_lambda_handler(event).await.expect("failed to handle event");
}
If you're using lambda_http
to receive HTTP events, you can also create http_lambda::Request
structures from plain text fixtures:
#[test]
fn test_my_lambda_handler() {
let input = include_str!("apigw_proxy_request.json");
let request = lambda_http::request::from_str(input)
.expect("failed to create request");
let response = my_lambda_handler(request).await.expect("failed to handle request");
}
Cargo Lambda provides a local server that emulates the AWS Lambda control plane. This server works on Windows, Linux, and MacOS. In the root of your Lambda project. You can run the following subcommand to compile your function(s) and start the server.
cargo lambda watch -a 127.0.0.1 -p 9001
Now you can use the cargo lambda invoke
to send requests to your function. For example:
cargo lambda invoke <lambda-function-name> --data-ascii '{ "command": "hi" }'
Running the command on a HTTP function (Function URL, API Gateway, etc) will require you to use the appropriate scheme. You can find examples of these schemes here. Otherwise, you will be presented with the following error.
Error: serde_json::error::Error
× data did not match any variant of untagged enum LambdaRequest
An simpler alternative is to cURL the following endpoint based on the address and port you defined. For example:
curl -v -X POST \
'http://127.0.0.1:9001/lambda-url/<lambda-function-name>/' \
-H 'content-type: application/json' \
-d '{ "command": "hi" }'
Warning Do not remove the
content-type
header. It is necessary to instruct the function how to deserialize the request body.
You can read more about how cargo lambda watch and cargo lambda invoke work on the project's documentation page.
Lambdas can be run and debugged locally using a special 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.
The Rust Runtime for Lambda integrates with the Tracing libraries to provide tracing and logging.
By default, the runtime emits tracing
events that you can collect via tracing-subscriber
. It also enabled a feature called tracing
that exposes a default subscriber with sensible options to send logging information to AWS CloudWatch. Follow the next example that shows how to enable the default subscriber:
use lambda_runtime::{run, service_fn, tracing, Error};
#[tokio::main]
async fn main() -> Result<(), Error> {
tracing::init_default_subscriber();
run(service_fn(|event| tracing::info!(?event))).await
}
The subscriber uses RUST_LOG
as the environment variable to determine the log level for your function. It also uses Lambda's advance logging controls if they're configured for your function. By default, the log level to emit events is INFO
.
This project includes Lambda event struct definitions, aws_lambda_events
. This crate can be leveraged to provide strongly-typed Lambda event structs. You can create your own custom event objects and their corresponding structs as well.
The AWS Lambda Rust Runtime requires a minimum of Rust 1.66, and is not guaranteed to build on compiler versions earlier than that.
See CONTRIBUTING for more information.
This project is licensed under the Apache-2.0 License.