kubek2k/simple-binary-lambda-tutorial.md

## simple-binary-lambda-tutorial.md

      
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              simple-binary-lambda-tutorial.md
            
          
    Preamble

The introduction of Custom Runtimes has opened up new possibilities when it comes to the spectrum of languages that can
be used in Amazon Lambda. This short document will show how to run virtually any statically linked binary on it. The
example will cover a stack built Haskell project.
Preparations


Create an Amazon Linux instance
compatible with Lambda, you can use
AMI link provided on the page (this is the one current for the time when this document was written,
but make sure you have a look at the page if something goes not the way you expected).

In theory it should be also possible to install Amazon Linux locally


SSH to the instance as you would usually do


Upgrade pip and aws-cli on the instance


sudo pip install --upgrade pip


sudo /usr/local/bin/pip install --upgrade awscli


Create an IAM user for lambda operations with AWSLambdaFullAccess policy attached

Enable programmatic access and export appropriate env vars:

export AWS_ACCESS_KEY_ID=..
export AWS_SECRET_ACCESS_KEY=..
export AWS_DEFAULT_REGION=..


Create IAM role called basic-execution-role with AWSLambdaBasicExecutionRole policy attached to it

note down role arn


Install bootstrap file as a new lambda layer


Save this file to file named bootstrap

#!/bin/sh

set -euo pipefail

while true
do
 HEADERS="$(mktemp)"

 # Pass the event straight to binary
 RESPONSE=$(curl -sS -LD "$HEADERS" -X GET "http://${AWS_LAMBDA_RUNTIME_API}/2018-06-01/runtime/invocation/next" | ./${_HANDLER})
 REQUEST_ID=$(grep -Fi Lambda-Runtime-Aws-Request-Id "$HEADERS" | tr -d '[:space:]' | cut -d: -f2)

 # Send the response
 curl -X POST "http://${AWS_LAMBDA_RUNTIME_API}/2018-06-01/runtime/invocation/$REQUEST_ID/response"  -d "$RESPONSE"
done


zip bootstrap.zip boostrap
aws lambda public-layer-version --layer-name binary-layer --zip-file fileb://bootstrap.zip
note down the LayerVersionArn

Create lambda binary


Create Haskell binary to run on the instance

Install stack

curl -sSL https://get.haskellstack.org/ | sh
Install required software

sudo yum install perl make automake gcc gmp-devel libffi zlib xz tar git gnupg


Create a simple project

stack new lambda
cd lambda
stack build
stack exec lambda-exe (to make sure it build and works properly)


Package the binary

cd .stack-work/install/x86_64-linux/lts-12.20/8.4.4/bin/ && zip ~/lambda.zip lambda-exe && cd - (beware of lts directory which may vary)


Upload lambda code


cd ~ && aws lambda create-function --function-name my-lambda --layers <layer_version_arn_from_above> --handler lambda --runtime provided --role <execution_role_arn> --zip-file fileb://lambda.zip

Test the lambda


aws lambda invoke --function-name my-lambda response.txt
if everything goes well you should see success - make sure by looking into output file response.txt