Cargil-demo

A basic three-tier architecture built and provisioned by terraform on AWS

This repo provides a template for running a simple three-tier architecture on Amazon Web services. The premise is that you have stateless app servers running behind an ELB serving traffic.

Outputs

After you run terraform apply on this configuration, it will automatically output:

1. An nginx reverse proxy server, that proxies the request to the app server in a private subnet. You can reach this server using the load balancer's address from the terraform output.
2. An app server configured to run a python flask app. The app handles requests via an api that processess only one get and post requests each. The gunicorn service is managed by supervisor.
3. A Multi-AZ MySQL server in a private subnet that stores the data.

Example:

app_server_address          = http://54.169.122.73:5000
db_instance_address         = mydb-rds.cddaja5olpcr.ap-southeast-1.rds.amazonaws.com
nginx_reverse_proxy_server  = http://web-elb-360621382.ap-southeast-1.elb.amazonaws.com

How to

• First, log into your AWS console and make a note of your key-pair name. Eg: lijoKeySingapore
• Then make a note of the path of your private key (eg: ~/.ssh/lijoKeySingapore.pem) in your local computer or vm from where you are running terraform apply.
• Make sure your local computer or vm has awscli installed. Run aws configure and enter your secret_key, access_key and default region. Note: This template was tested in the Singapore region. To be able to run on other regions, append the corresponding ami in the variables.tf file.
• That's it. Run it, like so:

  git clone https://github.com/lijoyoung/cargildemo.git
  cd cargildemo
  terraform init
  terraform plan
  terraform apply

• From the outputs, browse to the app_server_address. Eg: http://54.169.122.73:5000
• Click on the 'Add More' link and add a 'name of an animal' in the text box and hit Submit.
• Click on 'Show updated list' link and you will be back to the page which displays all the records in the database.