Getting started with the Node.js SDK

acklo lets you make updates to your app's configuration without needing to redeploy it.

You can use it to flip a feature switch, change your logging level so you can better respond to a bug, or anything else you can think of!

This guide covers how to integrate acklo with a Node.js app in minutes. It's based off an example in the Node.js SDK's GitHub repo.

Set up an example app

The example app we'll be integrating with acklo is a Node.js express server. If you already have an app you want to integrate, feel free to skip this step.

First, let's set up a new directory for the example app:

mkdir acklo_example
cd acklo_example
npm init -y
npm install express

Then, create an index.js file that starts a basic HTTP server:

const express = require("express");

async function main() {
  const port = 3001;
  const messageOfTheDay = "Hello world!";

  const app = express();

  app.get("/", (_, res) => {
    res.json({ motd: messageOfTheDay });
  });

  app.listen(port);
  console.log(`Listening on port ${port}`);
}

main().catch((err) => console.error(`Error initializing server: ${err}.`));

You can now run the server and make requests against it:

node index.js
>> Listening on port 3001

# In another terminal
curl localhost:3001
>> {"motd":"Hello world!"}

Create a config template

A config template file defines the properties that you want to remotely configured with acklo.

To keep this guide light, we'll get started by using a pre-built config template file. If you want to deep-dive into details about the file and its syntax, please check out the config template docs.

Create a file called acklo.config.yml with these contents:

version: v1
configuration:
  - id: config
    name: General configuration
    properties:
      - id: port
        name: HTTP port
        type: number
        default: 3001
      - id: motd
        name: Message of the day
        type: string
        default: Be good to each other

To get the values of these configuration properties using the SDK, we'll use the FQIDs of the properties. These FQIDs are derived by joining the config property group ID with the config property ID, separated by a full-stop. So for our example we have:

config.port
config.motd

Create your app on acklo

Next up we'll get your new application added to acklo. If you haven't signed up for acklo already, now's a good time to by visiting the sign up page!

Log in to your acklo account.
Navigate to your Applications page.
Click on the "Add application" button, or if you don't have any applications created you'll automatically be taken to the right page.
Enter your application's name and proceed to the next step, where you'll get your application's key (keep this page open because we'll be using it on the next step).

Set up the Node.js SDK

We're almost there! The last thing left to do is to integrate the acklo Node.js SDK with your app.

Install the Node.js SDK:
```
npm install @acklo/node-sdk
```

Update your index.js to integrate with acklo:

const express = require("express");
const AckloClient = require("@acklo/node-sdk").AckloClient;

// Instantiate the SDK
const acklo = new AckloClient({
  applicationKey: "[YOUR APPLICATION KEY]",
  environmentName: "local",
});

async function main() {
  // Connect to acklo to retrieve the latest config and stay in sync with
  // any config updates.
  await acklo.connect();

  // Get some config values from acklo.
  const port = acklo.get("config.port");
  const messageOfTheDay = acklo.get("config.motd");

  const app = express();

  app.get("/", (_, res) => {
    res.json({ motd: messageOfTheDay });
  });

  let server = app.listen(port);
  console.log(`Listening on port ${port}`);

  acklo.onConfigUpdate((updates) => {
    if (updates["config.port"]) {
      const newPort = updates["config.port"].newValue;
      server.close();
      server = app.listen(newPort);
      console.log(`Changed port to ${newPort}`);
    }
  });
}

main().catch((err) => console.error(`Error initializing server: ${err}.`));

Run your server again:

node index.js
>> Listening on port 3001
>> [acklo:info] Connected to acklo!
>> [acklo:info]   Instance name: ins-bitter-lake-w6tk
>> [acklo:info]   Instance URL: https://acklo.app/dashboard/applications/acklo_example/local/instances/55ab98d2-7aee-4598-aae5-eed1bf4bd6dc
>> [acklo:info]   Configuration: {
>> [acklo:info]     'config.log_level': 'trace',
>> [acklo:info]     'switches.motd': 'Be good to each other.'
>> [acklo:info]   }

# In another terminal
curl localhost:3001
>> {"motd":"Be good to each other."}

You can see that the config.motd property returned is now the default property we configured as part of the config template.

Hooray - Your application is now connected to acklo! You'll be able to find it on the acklo dashboard's list of applications.

Navigate to your application and change some of its configuration values. As soon as you change them in acklo they'll take effect on your server - give it a go!

What's next?

You can now perform live updates to your application using acklo! Keep exploring the documentation to learn more.

On this page