Minimal REST API Microservice

This repository contains a simple minimal REST microservice boilerplate written in python using Flask. It is meant to be a boilerplate/template to clone and quickly start a scalable microservice application.

The service implements an API that maps RESTful calls to a mongoDB database. It implements read, create, delete, update of accounts records in mongoDB, but you can pass in input any JSON file you want to insert into the database (only the field id is mandatory). The REST API is created using Flask, Flask-Injector and Connexion. Connexion is a python library to use OpenAPI, formerly Swagger, to describe and document RESTful APIs using a design-first approach.

Project Organization

|
├── /account-microservice
│   ├── /api       
|   |   ├── __init__.py                         <- Python init file
|   |   └── accounts.py                         <- Python file where methods are injected in the API
│   ├── /providers       
|   |   └── MongoProvider.py                    <- Python file where methods are implemented
│   ├── /swagger       
|   |   └── accounts-service-docs.yaml          <- API Swagger file
│   ├── app.py                                  <- Main python file to run the app
│   ├── Dockerfile                              <- Dockerfile used to build the image of the microservice
│   └── requirements.txt                        <- Requirements file with the list of the libraries needed
│
├── /img                                        <- Folder containing the images for this README file
├── LICENSE                                     <- License file
├── README.md                                   <- This Readme file
└── docker-compose.yml                          <- Docker compose file, used to run the microservice

Quickstart

Run the microservice

Run the following command in the root folder of the project (need docker and docker-composed installed).

docker-compose up

Consult the API documentation

To consult the API documentation just type the following address in a browser.

http://localhost:2020/v1.0/ui/

Endpoints available at http://localhost:2020/v1.0/{URI}:

Method	URI	Description
GET	/accounts/{user_id}	Retrieve data from the DB given an id
POST	/accounts/createUser	Insert data into the DB (Any JSON file, id mandatory)
PUT	/accounts/updateUser	Update data in the DB
DELETE	/accounts/{user_id}	Delete data from the DB

Customize the microservice

To customize the microservice for your own purpose, you have just to modify:

MongoProvider.py This file contains the implementation of the API methods. In this case it contains the methods to create, delete, update and read a record from mongoDB. Customize it with your desired implementation.
accounts.py: This file describes the API methods and what implementation should they run.
accounts-service-docs.yaml: This file contains the OpenAPI specification that describe the RESTful API. Modify this file according to your needs changing paths of the API methods and keeping in mind to modify parameters and operationId depending on what you edited in the accounts.py file. Consult the official documentation to learn more about OpenAPI.

Run your modified microservice with the command:

docker-compose build && docker-compose up

Create new microservices from the boilerplate

To create a new microservice:

Duplicate the account-microservice folder and rename the it XXXX-microservice with the name of your new microservice. Customize your new microservice following the instruction in the previous section.
Modify the docker-compose.yml file duplicating the account-microservice specifications and renaming them XXXX-microservice. Keep in mind to modify also the parameters - PORT=YYYY and ports with your desired exposed port.

Once again, run the microservices with the command:

docker-compose build && docker-compose up