Overview

This simple Lambda function invokes OpenWeatherMap.org API to retrieve the current weather for a city.

This is a TypeScript version of "PyWeather" - hence the name "JsWeather"

Perhaps more importantly, this version uses CDKv2 to create the Lambda function, and a CodeCommit/CodeBuild/CodePipeline for CI/CD.

This lets us have a direct comparison of SAM versus CDKv2.

Architecture

The following will be created:

A CI/CD Pipeline is created as well

Installation

First, you must request an API Key from OpenWeatherMap.org, for the "Current Weather Data" API.

This program can, of course, use the API Key you've already registered for PyWeather.

Register on OpenWeather Map.org

https://openweathermap.org/api

Request an API key.

Create a Secret in Secrets Manager

We'll store the OpenWeatherMap API key in Secrets manager.

First, you'll need to create the Secret (replace YOUR_API_KEY_HERE with yours!)

aws secretsmanager create-secret --name "openweather-api-key" --secret-string '{"apikey":"YOUR_API_KEY_HERE"}'
SECRETARN=$(aws secretsmanager describe-secret --secret-id openweather-api-key | jq -r '.ARN')
echo $SECRETARN

Build and Run

Run npm install first to install dependencies

npm install

Then run npm build

npm run build

CDK "synthesizes" into good old CloudFormation. To see it run:

cdk synthesize --app "npx ts-node bin/lambda.ts $SECRETARN"

This only shows the CFN for the Lambda function itself.

Then, you can deploy the Lambda function (bypassing the CI/CD Pipeline) by running this command:

cdk deploy --app "npx ts-node bin/lambda.ts $SECRETARN"

NOTE: You can just run this shell script:

./install.sh

Create a CodeCommit repo

The CI/CD Pipeline assumes you are using CodeCommit.

Follow these steps to create a repo

aws codecommit create-repository --repository-name "JsWeather-Demo"

Then, simply add that as a new remote , and push to it:

git remote add cc URI
git push cc

Install CI/CD Pipeline

This will create a CI/CD Pipeline that you can use for DevOps demos.

This CI/CD Pipelinewill peacefully co-exist with manually deploying as described above.

cdk deploy --force

NOTE: The pipeline assumes you are using AWS CodeCommit - NOT GITHUB!

Uninstall

Simply delete both Cloudformation stacks:

cdk destroy --app "npx ts-node bin/lambda.ts $SECRETARN" --force
cdk destroy --app "npx ts-node bin/ci.ts $SECRETARN" --force

Then, manually delete the SecretsManager secret (if desired).

Also remember to delete the CodeCommit repository, if you don't want to keep it.

Requirements

You need CDKv2 (2.158.0 or newer)

You need NodeJS 20

You need jq installed

Notes on Lambda version upgrades

To update the version of NodeJS, you must update the lambda-api-stack.ts, the test case (it asserts the NodeJS version), and possibly the dependencies in Package.json for the newer version.