By the end of this course, you will have deployed a set of microservices, powered by Flask and React, to Amazon Elastic Container Service (ECS).
More specifically, we'll:
- Configure CodeBuild to run when code is checked in to GitHub
- Run unit and integrations tests and check code for quality and formatting issues on CodeBuild
- Package the microservices as Docker images
- Push the images to Amazon Elastic Container Registry (ECR)
- Set up the appropriate ECS pieces to manage and provision EC2 boxes for deployment
- Configure RDS for data persistence
- Dump logs to CloudWatch
- Use the Application Load Balancer for load balancing
The two apps that you'll deploy are built using Flask and React, respectively.
Flask RESTful API
Built with Flask-RESTPlus, the server-side powers an API that follows RESTful design principles, using the basic HTTP verbs: GET, POST, PUT, and DELETE:
|Endpoint||HTTP Method||CRUD Method||Result|
|/auth/register||POST||CREATE||register a new user|
|/auth/login||POST||CREATE||log a user in|
|/auth/refresh||POST||CREATE||Obtain a new access token|
|/auth/status||GET||READ||check user status|
|/users||GET||READ||get all users|
|/users/:id||GET||READ||get a single user|
|/users||POST||CREATE||add a user|
|/users/:id||PUT||UPDATE||update a user|
|/users/:id||DELETE||DELETE||delete a user|
Along with Python and Flask, SQLAlchemy is used to interact with a Postgres database and Pytest is used instead of unittest for unit and integration testing. Finally, the app supports token-based authentication via the Flask-Bcrypt and PyJWT packages.
Curious about how these app were developed? Check out the Test-Driven Development with Python, Flask, and Docker and Authentication with Flask, React, and Docker courses.
Before diving in, let's take a minute to go over why some of the above tools are being used.
Flask and Django are the two most popular Python web frameworks. Django is older and more mature than Flask, but it's also more opinionated. On the other hand, Flask is lighter weight so it doesn't make many decisions for you. You get to decide how you want to implement things. At its core, Flask is simple yet extensible, which is perfect for developing RESTful APIs and microservices.
For more, review Django vs. Flask in 2019: Which Framework to Choose.
Flask-RESTPlus helps make building, maintaining, and documenting RESTful APIS with Flask easy.
Docker is a container platform used to streamline application development and deployment workflows across various environments. It's used to create the infrastructure required -- like installing Linux, configuring system-level dependencies, and running Python -- for the web app within a lightweight container than can be moved from your development machine to the production server quickly and easily.
Pytest is a test framework for Python that makes it easy (and fun!) to write, organize, and run tests. When compared to unittest, from the Python standard library, Pytest:
- Requires less boilerplate code so your test suites will be more readable.
- Supports the plain
assertstatement, which is far more readable and easier to remember compared to the
assertSomethingmethods -- like
assertContains-- in unittest.
- Is updated more frequently since it's not part of the Python standard library.
- Simplifies setting up and tearing down test state with its fixture system.
- Uses a functional approach.
React is technically not a framework; it's a view library. That said, when coupled with Create React App and React Router it can be considered more of a framework.
React Testing Library
As mentioned, React Testing Library (RTL) is a testing library designed specifically for React. It helps reduce the amount of boilerplate needed and provides a nice utility library, making it easier to write tests. When it comes to utility libraries, Enzyme is really your only other option. While Enzyme focuses on testing state and props, RTL focuses more on testing end user behavior. RTL has a much lower barrier to entry since it's less flexible and provides much fewer testing methods and options.
AWS is a cloud service platform that provides Infrastructure as Service (IaaS) and Platform as a Service (PaaS) solutions. They offer compute (EC2, Elastic Beanstalk, Lambda, ECS, and Fargate), storage (S3), database (RDS, DynamoDB, and Redshift), analytics (Athena and Kinesis), application (SQS and MQ), and DevOps (CodePipeline, CodeBuild, and CodeDeploy) services.
✓ Mark as Completed