Your first dead simple RESTful API with node.js and serverless
When it comes to trying to pick your first node.js project, there is no shortage of great ideas, in fact, there are entire GitHub repos dedicated to what your first project could be. Build a chatbot, No a weather API, what about a Pokedex?? It can be an overload to look at all of the possibilities right away.
In this tutorial, we’ll build a REST API that tells us about our users location!
The first thing we need to do is initialize our project, serverless comes with a large number of built-in templates, which makes it really easy to jump in and get started on our project, we’ll be using the
aws-nodejs template which applies the default syntax for setting up Lambda cloud functions on Amazon Web Services, Super cool!
serverless create --template aws-nodejs --path location-finder
Great! So now we have some boilerplate code, let’s open it and get familiar with what that looks like.
You should see a file tree that looks like this
One of the reasons that I think serverless makes such a good entry point for those creating their first API is just how simple everything is. For those who have ever interacted with an API this should seem pretty familiar, a good API should return at least a few things a
statusCode, and a JSON
Let’s talk about this file, this is where people who are new to serverless typically go glassy-eyed, especially if you’ve never seen a
.yml file before, but rest assured it's nothing scary. In fact the whole point of YAML files is that they're intended to be human readable! Check out this link to learn more.
The first thing that we need to do to make our lives easier during local development is to install a serverless plugin called serverless-offline which we can do by adding this snippet.
You should add this to the file in a place that it makes sense and won’t get in the way later. I placed mine just under the service name.
Now that we have told the framework that we intend to use this plugin, we need to install it using npm. The first step to installing anything with npm is to set up our npm dependency
npm init -y
to skip all of the setup options. Then
npm install --save-dev serverless-offline
Ok, the last thing we need to do to get our function talking to the outside world is to tell it how it should listen! Any good API has routes, and ours will too. In our
serverless.yml file let's turn our attention to the
functions section, this is where we'll define not only how the hello function that was created for us should be accessed, but also where we'll define all future functions, handlers, and events so it's important that you understand this especially.
Inside of the functions block, we can describe what functions our server(less) should care about,
hello is already described here, it's important to note that every function has a handler and every handler needs events if we expect to be able to interact with it from the outside world. In our example the only events we will be using are
http but there are a large number of events available!
Heres our route so far
handler.js [hello function]
We will be using this format as a template for future routes, see not too bad!
Start serverless in offline mode by typing
then, we can make our first request to
I use postman for testing, it’s easy to select the type of request you would like to make, and then see the result come back, but for
GET requests you can also just use your web browser.
Getting The Users Location
Getting the location at this point is pretty trivial as long as we have the IP address of our user, let's look through the request from earlier and see if we can find it.
Sure enough, if we look at the event from our
say/hello route, we see the users IP nested as
After researching a few npm packages, I found iplocation, it’s accurate and the size is minimal compared to others making it a good choice for our application!
Install this package with npm like before
npm install --save iplocation
I created a new handler file called
location.js, my file tree looks like this.
Now, let’s stub out our handler function. It should look something like this.
Adding the code to make it work is also very minimal, we need to
require("iplocation").default and pass the ip that we identified earlier.
iplocation is async
final serverless.yml functions
Here is a quick reference to what my serverless.yml file looked like after creating this handler.
Great, at this point you’ve created an extremely simple API that says hello, and also gets a users location based on their IP, let’s deploy this thing so you can see it really work! If you’ve gone through the steps to link your AWS account great, all you need to do is run
if you haven’t linked your AWS account, or don’t have one let’s fix that! This example is designed for AWS Lambda, so you’re already halfway there!