Photo by Phil Hearing on Unsplash

Overview

Postman is a popular tool to test APIs. Many people use Postman to test various endpoints quickly, but we can also create fully automated test suites. The application we will test in this blog series is a Client Manager built with Next.js. We will use a containerized version scottiecrump/client-address-next to get the application up and running quickly on our machine. Next, we will set up the application and review the API to test in the following sections.

Running the API Application with Docker

We will use Docker, a popular tool that bundles your application with all the libraries and services it depends on into a container package. The container is like a shipping container because you can run it on any machine long as it uses Docker. Docker handles problems such as, "It works on my machine, why not yours?" or "I want to run your application, but not have to install all the dependencies on my machine."

Use the "get started" instructions to install Docker on your machine. In addition, if you are using VSCode, consider installing the Docker extension. Once Docker is installed, create a new npm project and add a docker-compose.yml file in the root of the project with the following code:

version: '3.8'

services:
  api:
    image: scottiecrump/client-address-next
    environment:
      - MONGO_URI="mongodb://mongo:27017/addressbook"
    depends_on:
      - mongo
    ports:
      - 3000:3000
    restart: always
  mongo:
    image: mongo
    ports:
      - 27017:27017
    volumes:
      - mongo-data:/data/db
      - mongo-config:/data/configdb
    restart: always
volumes:
  mongo-data:
    driver: local
  mongo-config:
    driver: local

In the previous code, first, we specified the version of Docker Compose version: '3.8' to use. Next, we use services to identify the names of the containers we want to be built (i.e., api and mongo) and instructions.

For the api service:

api:
  image: scottiecrump/client-address-next
  environment:
    - MONGO_URI="mongodb://mongo:27017/addressbook"
  depends_on:
    - mongo
  ports:
    - 3000:3000
  restart: always

we use the scottiecrump/client-address-next image, the API application itself. Next, we set the value for MONGO_URI to connect to the Mongo database for environment. Note the use of mongo in the URL. Using "mongo" connects api to the MongoDB service by its name. Next, we specify ports to 3000:3000. The port specifies the port you want to expose in colon-separated values where the first port is your local machine and the second is the port specified inside the container. Then, we set restart to always to always restart the container if it crashes for some reason.

For the mongo service:

mongo:
  image: mongo
  ports:
    - 27017:27017
  volumes:
    - mongo-data:/data/db
    - mongo-config:/data/configdb
  restart: always

first, we set image to mongo to use the MongoDB Docker image. Next, we make the service available to the api service by setting ports to 27107:27107. Next, we use volumes to persist data saved to the database. For example, if we don't use volumes, any data stored in the database will be lost if we stop and restart the container. However, when we use volumes, we can stop and restart the container, and that data persists. The volume paths are prepended with the labels mongo-data and mongo-config, allowing them to be easily identified among other volumes that may be running on our machine. Next, we set restart to always to handle crashes. Finally, we specify all the named volumes sharable with other services using the default local driver.

Start the containers using the following command:

docker-compose up -d

Stop the containers using the following command:

docker-compose down

API Endpoint Overview

The API has five endpoints:

• POST /api/add-client used to create new clients
• GET /api/clients to retrieve all current clients
• GET /api/get-client?id to retrieve a single client
• POST /api/update-client to update a single client
• DELETE /api/delete-client to delete a single client

Detailed API documentation can be found here, including example requests with responses.

Part 1 Review

In review, we learned how to start the API to test using Docker and looked at the documentation for the API. In the next section, we will start testing the API using Postman.

The final source code can be found here

Part 2