fast notes on how to build and test rust lambdas in local dev on a mac

config

# this goes into your ~/.cargo/config file
[target.x86_64-unknown-linux-musl]
linker = "x86_64-linux-musl-gcc"

oxidize-the-lambda.sh

#!/bin/bash

# install the musl-cross build environment
brew install filosottile/musl-cross/musl-cross

# symlink
ln -s /usr/local/bin/x86_64-linux-musl-gcc /usr/local/bin/musl-gcc

# install the target toolchain
rustup target add x86_64-unknown-linux-musl

# build the lambda
cargo build --target x86_64-unknown-linux-musl

# start a docker container replicating the "provided" lambda runtime
# put your lambda into `bootstrap`
mkdir -p /tmp/lambda && \
cp target/x86_64-unknown-linux-musl/debug/your-lambda /tmp/lambda/bootstrap && \
docker run -i -e DOCKER_LAMBDA_USE_STDIN=1 \
    --rm \
    -v /tmp/lambda:/var/task \
    lambci/lambda:provided

# send your json blob input to STDIN somehow (paste or script output)