clojure-meetup-vilnius-2019-05-30

Demo project convert text to date.

Slides of the presentation can be found here: https://www.slideshare.net/Dainius/clojure-workflow-tokenmill-by-dainius-jocas

text2date-lambda

Custom AWS Lambda runtime with the Clojure tools-deps application compiled with GraalVM native-image.

TL;DR

Set these environment variables:

• MY_AWS_DEFAULT_REGION
• MY_AWS_ACCESS_KEY_ID
• MY_AWS_SECRET_ACCESS_KEY
• MY_S3_BUCKET
• MY_S3_FOLDER

Run:

make deploy-lambda-via-container

Lambda is ready to be used. Go to your AWS Console to work with the new stack named lambda-custom-runtime-text2dateLambda.

What is in the package

Most common operations are scripted in the Makefile:

• make build-native-image: inside the docker with the GraalVM builds native binary for the lambda and copies it to the project folder two files: server and libsunec.so
• make build-lambda-zip: inside the docker creates a custom AWS lambda runtime zip archive and copies it to the project folder as a function.zip file (for manual deployments).
• make deploy-custom-runtime-lambda: (use it if you have awscli installed and configured) builds a deployable lambda zip and deploys it to AWS.
• make deploy-lambda-via-container: builds lambda zip and deploys to AWS with your provided credentials (set the environment variables (e.g. (export MY_AWS_DEFAULT_REGION=eu-west-1 && <set other enviroment variables> && make deploy-lambda-via-container) or use something like dotenv, or some other way).

Prerequisites

This demo assumes that docker is available in the system.

Usage

• Modify request->response function to do the work you need.
• When needed add libraries to the deps.edn (with a little more work Git deps from private git repositories can be achieved).
• Build native image with GraalVM inside a docker
• Configure CI (for environment variables)
• Deploy to AWS Lambda

(defn request->response [request]
  (let [decoded-request (json/read-value request read-mapper)]
    (json/write-value-as-string decoded-request)))

CI/CD

.gitlab-ci.yml file includes a demo on how the lambda can be deployed from the Gitlab CI pipeline. Create environment variables in the CI/CD setup of your project.