Flask Replace App
I created this repo in order to practice basic flask development and explore the possible ways to deploy the app on AWS.
Tools used in this project
- Python and Flask - Building the project
- Insomnia - Api testing
- Zappa - Deploying to AWS Lambda
- Docker - Containerization
The app
The application is very simple, we have two routes:
/
The homepage of the app that was first created as a base for my flask journey
/repalce
The POST path for the project. requests sent to this route must contain a string of plaintext, the app then returns the string adding copyright © to certain words. Replaceable words:
- Oracle
- Amazon
- Deloitte
- Microsoft
Deployment methods
The project is simple but that only means it has less restrictions when deploying, the possibilities are varied and depend on the desired scale.
Lambda - or any serverless function service
Lambda was my choice for this project since it is the simplest, since the application does not require a database or any sort of side services (Redis, RabbitMQ, etc.. ) I chose to deploy to lambda since it is also the cheapest option. Using the Zappa Serverless python library the deployment was very simple and created all that was needed for the application to be deployed on AWS, including an API Gateway endpoint that can be found here. Unfortunately Zappa still does not have support for lambda@edge which would have been the best choice for this deployment, but after trying and researching I realized that for lambda@edge to work, another build would be needed.
Kubernetes
To deploy to kubernetes (My personal favorite although it requires much more overhead) You will need to create a kubernetes cluster and set up an ingress controller on it then you can use my helm chart found here
The docker image has already been created and is available on DockerHub under fasoolya/flask-replace-app The image has already been set in the values files so all you need is to cd into the directory and `helm upgrade --install release . --values values.yaml
I have also created IaC files using terraform for AWS EKS you can find them here
The IaC creates a vpc with 6 subnets, 3 public and 3 private and then creates an EKS cluster within the VPC.
ECS
Since ECS makes it simple to deploy a containerized app it is also a very good option for deployment
EC2 - Any VM
The application can also be deployed to any VM, the requirements.txt file includes any needed libraries (its just flask) and a simple system.d file can be added and then enabled allowing the application to run on a bare metal deployment. A load balancer can later be added, in addition to an autoscaling group that uses a custom made image to allow for scalability.