Overview: Understanding the Boilerplate

Introduction

Making a brief overview of the Boilerplate, there are two directories (/node and /graphql) and the manifest.json file, which is an important file to your VTEX IO app because it will be the first communication point with the VTEX IO.

Manifest Overview

In the manifest.json file, you will find the app's name, vendor, version, and other information to pay attention to: builders, policies and dependencies. In this initial state, we have the following configurations:

builders: what builders your app will need. In this case, we have, so far, only the docs builder and the node builder, with their respective versions;
policies: if the app being built needs to access some external services or get some specific data from other places, it needs to declare so, even for external APIs. At this point, we have no specific policies yet;
dependencies: other VTEX IO apps your app depends on. As addressed below, for this course, we need to also link the events-example app, as it is listed as a dependency for this course app.

`/node` Directory Overview

All directories used over the course are already in this initial project. Most of the directories are empty and will be filled throughout the course.

/node/clients: both files are almost blank and are now just placeholders for the next steps.
/node/handlers: contains a handler that will be used in the next steps.
/node/utils: you will find a file containing global constants declarations (/node/constants.ts).
/node/index.ts: contains the initial declarations for the app functionality like the cache declaration and the service declarations, which will be incremented during the course. Here is also possible to export resolver functions implementations.

/node/service.json: It describes your REST API and some characteristics that will directly impact your app's infrastructure attributes. Your service.json file will be found inside your app's /node folder, and will look similar to this:

{
"memory": 256,
"timeout": 2,
"minReplicas": 2,
"maxReplicas": 4,
"routes": {
"status": {
  "path": "/_v/status/:code",
  "public": true
}
}

Field	Type	Description
memory	MegaBytes.	How much memory your app will have allocated. This value will be overwritten if IO detects that your app is abusing memory usage
timeout	Seconds	VTEX.IO infra will abort the connection if the request time is longer than timeout
minReplicas	Integer	When your app is running, how many minimum replicas will be available
maxReplicas	Integer	The largest amount of replicas that will be available
routes	-	Describes your app's REST routes, inside you will descibe the name, (ex: ssr), the path, and if its public or private

`/graphql` Directory Overview

On this directory, you will find only the empty directories and the /graphql/schema.graphql blank file. This will all be filled throughout the course, as well.

Dependencies

For this course, this app has a dependency on the events-example app. The events-example app, when linked to your account and workspace, is responsable for providing events examples. Over the course, as we approach the events topic, there will be a more complete overview of the events-example app.

Activity

For now, clone (git clone) the events-example app from this repository and run vtex link in it's directory.

Without the events-example app, this course app will not be successfully linked, as the events-example app is listed as a dependency.

After running vtex link on the events-example app, the terminal should show a healthcheck route that will be used later. It looks like this:

lucis / service-course