Node, Express and MongoDB with generic controllers

Overview

This is an easy, basic and raw example of HOW to implement an API with Node, Express and MongoDB (Atlas) with generic controllers

This project is based on the template node-express-mongo-db. Check out that repo's README for setup and development.

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CRUD Generic Controllers

Using the Generic Controllers

We are going to use our generic controllers to perform common CRUD operations, giving a model:

• Create a document in a collection (POST)
• Retrieve all the documents in a collection or one document by its ID (GET)
• Update a document in a collection by its ID (PUT)
• Delete a document in a collection by its ID (DELETE)

If you need to create a custom controller for a particular resource, add it to /src/resources/collection/controllers.js and update the router with the route and the exported method (controller) /src/resources/collection/router.js

Controllers and Side Effects

For operations involving side effects, or, everything outside the scope of retrieving (GET) you should definitely need authentication and authorization before executing the operation. You don't want random people creating, updating, deleting your resources. This should be obvious, however, if you are using this a template be extremely careful since we are not protecting endpoints (it is not the goal of this material).

Once you have the proper logic in place to allow certain entities to perform CRUD operations, and, if you are going to use generic controllers, just chain the method and pass the imported controller in your /src/resources/collection/router.js

So, as an example, if you want to support the creation of a new application in the applications collection your /src/resources/applications/router.js would look like:

router.route('/').get(controllers.getSomeOrAll)
  .post(controllers.createOne)

If you want to allow, updating and deleting an application in the applications collection:

router.route('/:id').get(controllers.getOne)
  .put(controllers.updateOne)
  .delete(controllers.deleteOne)

Create new MongoDB collection

We are going to connect to our cluster with the mongo shell

MongoDB Community Shell

Mac Installation

brew install mongodb/brew/mongodb-community-shell

Set the proper path

Add <your mongo shell's download directory>/bin to your $PATH variable

export PATH=/usr/local/Cellar/mongodb-community-shell/4.2.0/bin:$PATH

Execute the connection string

mongo "mongodb+srv://your-mongodb-endpoint.1ckup.mongodb.net/your-database" --username your-user

... then, enter your password.

Create new collection

db.createCollection('applications')

List connections

show collections

Sample output:

applications
objectlabs-system
objectlabs-system.admin.collections
users

Import the sample data into the collection

You can get the list of hosts through Web UI https://cloud.mongodb.com/ (Go to the Cluster and check its Overview data) or using the mongo cli

mongo "mongodb+srv://your-mongodb-endpoint.1ckup.mongodb.net/your-database" --username your-user
rs.status()
# Check under members key

Then, import the data...

mongoimport --host your-mongodb-endpoint-shard-00-02.1ckup.mongodb.net:27017,your-mongodb-endpoint-shard-00-00.1ckup.mongodb.net:27017,your-mongodb-endpoint-shard-00-01.1ckup.mongodb.net:27017 \
  --ssl -u your-username -p 'your-password' \
  --authenticationDatabase admin  --db your-database\
  --collection applications --drop --file ./app-mock-data.json

Sample output:

2021-06-21T14:05:44.817-0700	[########################] your-database.applications	77.0KB/77.0KB (100.0%)
2021-06-21T14:05:45.146-0700	[########################] your-database.applications	77.0KB/77.0KB (100.0%)
2021-06-21T14:05:45.146-0700	1000 document(s) imported successfully. 0 document(s) failed to import.

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Kudos

• Extended version of Scott Moss > FEM API Design in Node.js
• Mock data provided by: https://www.mockaroo.com/