Python Flask Simple Web Application

General info

A simple web service responds HTTP GET requests and returns a JSON containing:

• Timestamp

• hostname

  Example response

  {
    "Timestamp": "Sat, 10 Sep 2022 14:22:49 GMT",
    "hostname": "29ef7d9092cb"
  }

Technology

• Alpine 3.16
• Python 3.10.7
• Flask 2.2.2
• Docker 20.10.17
• Minikube v1.26.1
• Kubernetes v1.24.3
• Prometheus v2.31.1

Bootstrap

Unix-like (macOS/Linux)

1. Run the script using the example below:
   ./.CICD/local/NIX/bootstrap.sh
2. Run the command below to connect LoadBalancer services minikube --log_file tunnel.log tunnel
   1. This script might ask you for sudo password if enabled in the system, please enter your user password and continue
   2. This command will display an output like the example below:

      Status:
           machine: minikube
           pid: 46831
           route: 10.96.0.0/12 -> 192.168.39.81
           minikube: Running
           services: []
        errors: 
                    minikube: no errors
                    router: no errors
                    loadbalancer emulator: no errors
      

3. Application responds to requests using the simple.info domain.
   Use the IP address in step 2.2, 192.168.39.81 in the example, to punch a name record in /etc/hosts file

   192.168.39.81 simple.info
   

Development

Docker is used to develop and test the application

1. Simply build the docker image
   docker build --tag simple-python-web-app:development -f .CICD/docker/development.Dockerfile .
2. Run the built image
   docker run --name simple-web-app -p 5000:5000 simple-python-web-app:development
3. Application will start to serve on port 5000 and can be accessed using this URL: http://127.0.0.1:5000

Deployment

minikube

1. Build the docker image docker build --tag simple-python-web-app:production -f .CICD/docker/production.Dockerfile .

2. Tag the production image for docker registry docker tag simple-python-web-app:production localhost:5000/simple-python-web-app

3. Push the image docker push localhost:5000/simple-python-web-app

   Note

   You can use the deployment script ./.CICD/deploy.k8s.sh

4. Visit http://simple.info address in your favourite browser