Intro

Update: This tool is now deprecated, I would advise against using this but I’ll keep this post up just in case

Using this amazing tool I found called Apex we will get a basic Python, Node.js, Ruby, etc AWS Lambda API running in minutes! I’ll be using Python for this guide but it only takes 1 line of code to change the runtime you want :)

If you want to see a real world application of this kind of API see one of my projects here

Step One: Installing & Setting up AWS CLI + Apex

The easiest way to setup Apex is to use the AWS CLI, though this is completely up to you. Apex also allows configuration via Environment Variables, IAM roles and more.

So let’s install AWS CLI

MacOS (My OS at the time of writing) brew install awscli Debian Linux sudo apt-get install awscli

Run the command aws configure and fill out your credentials, if you don’t understand what it’s asking for go to the IAM Management Console on your AWS Dashboard and follow the steps for adding a user.

Onto the Apex installation, fortunately Apex gives us an easy one liner for this

curl https://raw.githubusercontent.com/apex/apex/master/install.sh | sh

Windows Binary

Step Two: Slapping together an API (the easy and right way)

Intro to Apex

We could do apex init for this step but I think going through it yourself is better plus I need another step in this guide.

There are two important pieces to your Apex setup one being a project.json file, the other being the structure of a functions directory. The project.json file sets project wide settings as well as setting default values for all functions. Create a functions.json file with the following values

project.json - Setting generic parameters for project / functions. available parameters

{
  "name": "My AWS API",
  "description": "Collection of lmabda functions to accomplish tasks of a sort",
  "memory": 128,
  "timeout": 5,
  "role": "arn:aws:iam::910144801136:role/AWSAPITools_lambda_function" // Note this is just my role, yours that you create will be different
}

Now onto the actual functions directory which will (obviously) hold our functions’ code. The directory will be made up of folders with the name of whatever function you want it to hold. Each folder will contain be an index file, necessary dependencies, and an optional function.json file.

Project Structure

 | 
 | - project.json
 | - functions/
 |   |
 |   | - ExampleFunctionWithOverrides
 |   |   |
 |   |   | - function.json (json object with updated parameters)
 |   |   | - main.py (index.js for Node.js, view Apex's documentation for other runtimes) 
 |   | - ExampleFunctionNoOverrides
 |   |   |
 |   |   | - main.py 

main.py

import json

def handle(event, context):

    body = "Yoo, what's good Lambda?"
    statusCode = 200

    return {
        'statusCode': statusCode,
        'body': json.dumps(body)
    }

Running

And boom! We now have a working lambda function and to see it in action running on AWS we only need 2 commands.

apex deploy
apex invoke ExampleFunction 

Now you should see in your console:

{"statusCode": 200, "body": "\"Yoo, what's good Lambda?\""}

Parameters for Project / Function

Step Three: Setting up your API Gateway on AWS

API Creation

Last step until we have a functioning API! Log into your AWS account and go to the API Gateway service (Make sure you’re in the same region as Apex is configured with). Hit get started and you will be greeted with an easy new API creation form fill it out with your information like so

Adding methods and endpoints to our APIS

This next part is pretty straight forward if you know REST APIs. We’ve been dumped onto another API configuration form. This form allows us to add and remove end points and methods to connect to them as well as deploying this API to production or any other stage you choose.

First thing’s first let’s add an end point. In the actions drop down select create resource and fill in the resource’s name with something like “hello”, “apiexample”, etc.

Now select your newly created resource and in the actions drop down select create method and choose how you want to connect to it. I’m doing GET because well it makes sense and it’s easy. This is the part where we choose what happens when we hit the endpoint. Right now we are going to select Lambda Function, our lambda region and the lambda function we want, like so.

Deploying our API & Testing

Now we have everything we need to deploy and test. In the actions dropdown select ‘Deploy API’ and create a new deployment stage (I used prod) and a description if you’d like and smash that mother ‘fuckin deploy button.

After deployment, AWS redirects you to the stages section. Explore through the newly created API and click on the method you created. AWS hands you a nice little invoke URL. Now if you used GET as your method you can just click on it and see the fruits of your label. If you didn’t use GET you can just use Postman or Fiddler to request it.

Postman Example

Outro

It’s been a ride, friends, we have a working and maintainable bare bones API project with Apex using any language(s) that you choose. See y’all in the next post or maybe on my github @leobeosab, twitter @ride_faster or on the street @Grand Rapids, Mi