3 Tier Architecture AWS best practices: WordPress application

Wordpress on AWS - Terraform for multiple teams Project

GitHub: https://github.com/serglit72/terraform-aws-wordpress

In this project, we aimed to build a three-tier WordPress application using Terraform in a real-world environment where the DevOps team is distributed worldwide and independent contributors or groups provide each block. To make it possible we use a "remote" backend for Terraform on an S3 bucket (versioning enabled) and DynamoDB to keep the state locked for only one transaction at a time.

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Resources will be created:

Backend-S3-DynamoDB

• 1 x S3 bucket (prod env)

• 1 x DynamoDB table

Infrastructure

• 1 x VPC

• 2 x Private Subnets

• 2 x Public Subnets

• 1 x Public Route table

• 1 x Private Route table

• 1 x Internet Gateway

• 2 x NAT Gateway

Frontend layer

• 1 x Application Load Balancer

• 1 x Auto Scaling Group (2 minimum 99 maximum instances-horizontally scalable)

• 1 x security group for Web layer

• 2 x EC2 instances (minimum) (WordPress)

Database layer

• 1 x RDS Aurora cluster with 1 writer, 1 reader instances (horizontally scalable)

• 1 x security group for Database layer

Steps:

1. Git clone the repo

2. Go to repo directory:

cd united-wordpress-aws

1. Check if aws s3 is available:

aws s3 ls

1. Copy content from the "template.txt" file or edit and save it as "envs/prod/prod.tfvars" file:

vim envs/prod/prod.tfvars

public_key = "~/.ssh/id_rsa.pub"
region     = "your-region"              # change if needed
key_name   = "your_key_name"            # change
domain     = "yourdomainname.com"       # change
zone_id = "copy-from-route53-region-ID" # change
rds_username = "admin"                  # change the username 
rds_password = "admin123"               # change the password 
tags = {
  Name = "Wordpress-VPC"
  Team = "AWS"
}

1. Run script to install Terraform environment and version:

bash scripts/installation.sh

Backend Setup (DynamoDB +S3)

Run Makefile:

$ make backend

Script also will create the "backend.tf" file into VPC,ASG,RDS folders

1. Optionally, if your VM does not have administrator priviliages, run below commands to add your AWS credentials as environment variables.

$ export AWS_ACCESS_KEY_ID={Your AWS_ACCESS_KEY_ID} 
$ export AWS_SECRET_ACCESS_KEY={Your AWS_SECRET_ACCESS_KEY} 

1. Finaly, run

$ make build

And wait for about 20 mins

For Deleting Resources and delete the Application:

$ make destroy

TROUBLESHOOTING:

In case of error when deleteing S3 bucket use AWS console and manually empty and delete the bucket

│ Error: deleting Amazon S3 (Simple Storage) Bucket (terraform-tfstate-prod-1999999999999): BucketNotEmpty: The bucket you tried to delete is not empty. You must delete all versions in the bucket.
│       status code: 409, request id: HAMSEY42N6MG45QR, host id: h8kkpMo03yqa5U+esfQJZwgeaenEg63dqUexPPYV4b4j63JNfQjiJO8WlwyifBF5qK5OeE7ZXlU=
│ 

Test Database accessibility:

From EC2 instance of Web in your VPC!!! DB endpoints should be available from the final outputs

[ec2-user@ip-10-0-1-157 ~]$ mysql -h aurora-cluster-demo.cluster-ctxxweudrhd8.us-west-1.rds.amazonaws.com -u admin -p mydb
>
Enter password: ******

You should see:

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 219
Server version: 8.0.23 Source distribution

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