serverless-lambda-functions

Learn how to use AWS Lambda functions.

This repository is based on the exercises of the book Serverless Applications with Node.js by Slobodan Stojanović and Aleksandar Simović

Install

npm install

Setup Claudia to work with your AWS

Besides signing up to AWS, you also need to setup keys for Claudia to access your AWS resources.

mkdir ~/.aws
touch ~/.aws/credentials
vi ~/.aws/credentials

In credentials file, write your AWS access key and your AWS secret access key. Note these should never be shared publicly or commited to a repository. The AWS key is generated in the IAM management console, when you login to AWS. If you don't know what your secret access key is, it's best to create a new one, since Amazon will only communicate that key once, when it's created, and won't give it again.

content of the file credentials:

[default]
aws_access_key_id=YOUR_ACCESS_KEY
aws_secret_access_key=YOUR_ACCESS_SECRET

Deploy to AWS the first time

The file claudia.json needs to be deleted because it is specific to a given AWS production environment.

rm claudia.json
npm run create

Note this will deploy to the EU Ireland datacentre. Edit package.json script if you wish to deploy to a different datacentre. A claudia.json file will be generated locally.

The successsful response should mention a "url" for your "api". Append /pizzas to it in a browser to get your JSON response.

Further deployments

npm run update

Chapter 3 - setup dynamo db table

~/projects/serverless-lambda-functions $ cat setup_pizza-order_dynamoDB.sh
aws dynamodb create-table --table-name pizza-orders \
   --attribute-definitions AttributeName=orderId,AttributeType=S \
   --key-schema AttributeName=orderId,KeyType=HASH \
   --provisioned-throughput ReadCapacityUnits=1,WriteCapacityUnits=1 \
   --region eu-west-1 \
   --query TableDescription.TableArn --output text

aws dynamodb describe-table --table-name pizza-orders  --region eu-west-1

and running this, the output will be similar to

~/projects/serverless-lambda-functions $ bash setup_pizza-order_dynamoDB.sh
arn:aws:dynamodb:eu-west-1:981192392543:table/pizza-orders
{
    "Table": {
        "AttributeDefinitions": [
            {
                "AttributeName": "orderId",
                "AttributeType": "S"
            }
        ],
        "TableName": "pizza-orders",
        "KeySchema": [
            {
                "AttributeName": "orderId",
                "KeyType": "HASH"
            }
        ],
        "TableStatus": "CREATING",
        "CreationDateTime": 1558430353.101,
        "ProvisionedThroughput": {
            "NumberOfDecreasesToday": 0,
            "ReadCapacityUnits": 1,
            "WriteCapacityUnits": 1
        },
        "TableSizeBytes": 0,
        "ItemCount": 0,
        "TableArn": "arn:aws:dynamodb:eu-west-1:981192392543:table/pizza-orders",
        "TableId": "a5c72b11-d6be-4988-b0b6-a04afc1e0cbc"
    }
}

todo

• Setup GraphQL in front of each end point to let the client decide how to query the data.
• Abstract CRUD code and inherit for each controller, so that pizzas and orders can run the same functionality.
• Switch to Typescript.
• Add linting.
• Add unit tests with Jest and test coverage report (istanbul).
• JSDoc documentation.
• Setup working locally.
• In each API response, link to other useful endpoints.
• Introduce Continuous Integration and Continuous Delivery (canary deployment, AB testing are all possible with serverless, see presentation notes about Amazon on Serverless in Amsterdam, 29th May 2019).