Overview

This system demonstrates a simple web application based on a Flask/Redis backend and a simple javascript process that runs on the client.

The server allows the user to load a webpage where they can vote "Yes" or "No." After each vote, the system displays the total number of votes for each option.

Launch Locally (Development)

To launch the system locally:

• Create a virtual environment and install the libraries

  python3 -m venv .venv
  source .venv/bin/activate
  pip install -r requirements.txt
  

• Verify that all tests pass

  pytest
  

• Create an .env file

  REDIS_HOST=localhost
  REDIS_PORT=6379
  

• Run the Redis server

  docker run -d -p 6379:6379 redis
  

• Run the Flask server (sudo needed because we launch on port 80)

  sudo .venv/bin/python app.py
  

  Alternate, launch with gunicorn (the way we will do in production)

  sudo .venv/bin/gunicorn --bind 0.0.0.0:80 "app:launch_app()"
  

• Open http://localhost in a web browser

Launch in Cloud9

• Start a t3.medium instance for Cloud9
• Follow the steps from Launch Local
• Edit the Security Group on the underlying EC2 instance
  • Add port 80 on 0.0.0.0/0
• Open http://<EC2 IP> in a web browser

Launch on EC2 (Console Deployment)

The steps to deploy on an EC2 instance are contained in userdata.sh. Study this file, and be sure you understand each line.

• Create an EC2 instance

  • Name: voting_monolith_console
  • Key Pair: vockey
  • Network Settings: Allow HTTP traffic from the internet
  • Advance Details / User Data - paste in userdata.sh

• Connect to the instance

  ssh -i ~/.ssh/labsuser.pem ec2-user@<instance IP>
  

• On the instance, watch the deploy via the log

  tail -f /var/log/cloud-init-output.log
  

• Once the message Cloud-init v. 22.2.2 finished is displayed, press ctrl-c to exit tail.

• Open http://<EC2 IP> in a web browser

Launch on EC2 (AWS CLI Deployment)

To launch with the AWS CLI, we specify all settings as command line options. Before we launch the first time, we must create and configure the security group.

• Create a security group

  aws ec2 create-security-group --group-name httpssh --description "Security group for HTTP/SSH (80/20) access"
  

• Allow HTTP (80)

  aws ec2 authorize-security-group-ingress --group-name httpssh --protocol tcp --port 80 --cidr 0.0.0.0/0
  

• Allow SSH (22)

  aws ec2 authorize-security-group-ingress --group-name httpssh --protocol tcp --port 22 --cidr 0.0.0.0/0
  

• Launch the instance

  aws ec2 run-instances --image-id ami-06b21ccaeff8cd686 --instance-type t2.micro --key-name vockey --security-groups httpssh --user-data file://userdata.sh --tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=voting_monolith_cli}]'
  

• Wait for cloud-init to complete the userdata steps.

• Open http://<EC2 IP> in a web browser