Following our project scenario ‘Hodan School’ we are going to implement highly available 3 tier architecture on AWS. We are going to evolve web application WordPress, compute options, load balancing and database services until it's a scalable and resilient architecture.
In their 3 tier architecture applications are organized into three logical tiers: the presentation layer, the business logic layer and the data storage layer. Our web application will be used in a client-server application that has frontend, the backend and the database. The prime drivers for three-tier architecture are:
- Decoupling
- Independent scalability
- Separately developed, managed and maintained by different teams
Amazon Web Service (AWS) is a cloud platform that provides different cloud computing services. We shall be using AWS services to design and build a three-tier cloud infrastructure such as EC2, Auto Scalling Group (ASG), VPC and Elastic Load Balancer (ELB) aming to be highly available and fault tolerant.
Web-App template
This project consists of different stages, each implementing additional components of the architecture.
Login to an AWS account using a user with admin privileges and ensure your region is set to us-east-1 N. Virginia
Use One-Click Deployment to auto configure the VPC which WordPress will run from
Wait for the STACK to move into the CREATE_COMPLETE state before continuing.
Or get this yaml file and upload on your CloudFormation Stack.
I will be using bootstrap to provision MariaDB, WordPress, install EFS, mount EFS file system to WordPress and populate values from AWS Parameter Store.
Create SSM Parameter Store values for WordPress In this stage we will start storing configuration information within the SSM parameter store which scales much better than attempting to script them. Select AWS System Manager from services then Click on Parameter Store under Application Management on the menu on the left
Create Parameter - DBUser (the login for the specific wordpress DB)
Click Create Parameter Set Name to /HDN/Wordpress/DBUser Set Description to Wordpress Database User
Set Tier to Standard
Set Type to String
Set Data type to text
Set Value to hdnwordpressuser
Click Create parameter
Create Parameter - DBName (the name of the wordpress database)
Click Create Parameter Set Name to /HDN/Wordpress/DBName Set Description to Wordpress Database Name
follow same way
Set Value to hdnwordpressdb
Create Parameter - DBEndpoint (the endpoint for the wordpress DB .. )
follow same way
Set Value to localhost
Create Parameter - DBPassword (the password for the DBUser)
Click Create Parameter Set Name to /HDN/Wordpress/DBPassword Set Description to Wordpress DB Password
Set Tier to Standard
Set Type to SecureString
Set KMS Key Source to My Current Account
Leave KMS Key ID as default Set Value to h0d4nF1L35 Click Create parameter
Create Parameter - DBRootPassword (the password for the database root user, used for self-managed admin)
Click Create Parameter Set Name to /HDN/Wordpress/DBRootPassword Set Description to Wordpress DBRoot Password
Set Tier to Standard
Set Type to SecureString
Set KMS Key Source to My Current Account
Leave KMS Key ID as default Set Value to h0d4nF1L35 Click Create parameter
In this stage, you are going to provision an RDS instance using the subnet group to control placement within the VPC. Normally you would use multi-az for production, to keep costs low, for now you should use a single AZ as per the instructions below.
Click Databases
Click Create Database Click Standard CreateClickMySqlunderEngine optionsUnderVersionselectMySQL 5.7.31` (best aurora compatibility for snapshot migrations)
Scroll down and select Free Tier under templates this ensures there will be no costs for the database but it will be single AZ only
under Db instance identifier enter hdnWordPress under Master Username enter enter the value from here https://console.aws.amazon.com/systems-manager/parameters/HDN/Wordpress/DBUser/description?region=us-east-1&tab=Table
under Master Password and Confirm Password enter the value from here and confirm https://console.aws.amazon.com/systems-manager/parameters/HDN/Wordpress/DBPassword/description?region=us-east-1&tab=Table
Under DB instance class, then Burstable classes (includes t classes) make sure db.t2.micro is selected
Scroll down, under Connectivity, Virtual private cloud (VPC) select HDNVPC
Subnet group wordpressrdssubnetgroup automatically populated
Make sure Publicly accessible is set to No
Under Existing VPC security groups add HDNVPC-SGDatabase and remove Default
Under Availability Zone set us-east-1a
Under Database authentication select Password authentication
Scroll down and expand Additional configuration
in the Initial database name box enter the value from here https://console.aws.amazon.com/systems-manager/parameters/HDN/Wordpress/DBName/description?region=us-`east-1&tab=Table
Scroll to the bottom and click create Database
** this will take anywhere up to 30 minutes to create ... it will need to be fully ready before you move to the next step - tea time !!!! **
EFS file system designed to store the wordpress locally stored media. This area stores any media for posts uploaded when creating the post as well as theme data. By storing this on a shared file system it means that the data can be used across all instances in a consistent way, and it lives on past the lifetime of the instance.
Move to the EFS Console https://console.aws.amazon.com/efs/home?region=us-east-1#/get-started
Click on Create file System
We're going to step through the full configuration options, so click on Customize
For Name type HDN-WORDPRESS-CONTENT
This is critical data so .. ensure Enable Automatic Backups is enabled.
for LifeCycle management leave as the default of 30 days since last access
You have two performance modes to pick, choose General Purpose as MAX I/O is for very specific high performance scenarios.
for Throughput mode pick bursting which links performance to how much space you consume. The more consumed, the higher performance. The other option Provisioned allows for performance to be specified independent of consumption.
Untick Enable encryption of data at rest .. in production you would leave this on, but for now we focus on architecture it simplifies the implementation.
Click Next
Network Settings
In this part you will be configuring the EFS Mount Targets which are the network interfaces in the VPC which your instances will connect with.
In the Virtual Private Cloud (VPC) dropdown select HDNVPC
You should see 3 rows.
Make sure us-east-1a, us-east-1b & us-east-1c are selected in each row.
In us-east-1a row, select sn-App-A in the subnet ID drop-down, and in the security groups drop-down select HDNVPC-SGEFS & remove the default security group
In us-east-1b row, select sn-App-B in the subnet ID dropdown, and in the security groups dropdown select HDNVPC-SGEFS & remove the default security group
In us-east-1c row, select sn-App-C in the subnet ID dropdown, and in the security groups dropdown select HDNVPC-SGEFS & remove the default security group
Click next
Leave all these options as default and click next
We wont be setting a file system policy so click Create
The file system will start in the Creating State and then move to Available once it does..
Click on the file system to enter it and click Network tab
Scroll down and all the mount points will show as creating keep hitting refresh and wait for all 3 to show as available before moving on.
Note down the fs-XXXXXXXX file system ID once visible at the top of this screen, you will need it in the next step.
Add an fsid to parameter store
Now that the file system has been created, you need to add another parameter store value for the file system ID so that the automatically built instance(s) can load this safely.
Move to the Systems Manager console https://console.aws.amazon.com/systems-manager/home?region=us-east-1#
Click on Parameter Store on the left menu
Click Create Parameter
Under Name enter /HDN/Wordpress/EFSFSID Under Description enter File System ID for Wordpress Content (wp-content)
for Tier set Standard
For Type set String
for Data Type set text
for Value set the file system ID fs-XXXXXXX which you just noted down (use your own file system ID)
Click Create Parameter
Open the EC2 console https://console.aws.amazon.com/ec2/v2/home?region=us-east-1#Instances:sort=desc:tag:Name
Click Launch Templates under Instances on the left menu
Click Create Launch Template
Under Launch Template Name enter Wordpress
Under Template version description enter Server DB and App
Check the Provide guidance to help me set up a template that I can use with EC2 Auto Scaling box
Under Amazon machine image (AMI) - required click and locate Amazon Linux 2 AMI (HVM), SSD Volume TYpe, Architecture: 64-bit (x86)From Quick Start
Under Instance Type select t2.micro (or whichever is listed as free tier eligible)
Under Key pair (login) select Don't include in launch template
Under networking Settings Skip Subnet make sure Under Security Groups select HDNVPC-SGWordpress-..
Scroll to the bottom, Expand Advanced Details Under IAM instance profile select HDNVPC-WordpressInstanceProfile
Under Credit specification select Unlimited
Add User-Data
#!/bin/bash -xe
DBPassword=$(aws ssm get-parameters --region us-east-1 --names /HDN/Wordpress/DBPassword --with-decryption --query Parameters[0].Value)
DBPassword=`echo $DBPassword | sed -e 's/^"//' -e 's/"$//'`
DBRootPassword=$(aws ssm get-parameters --region us-east-1 --names /HDN/Wordpress/DBRootPassword --with-decryption --query Parameters[0].Value)
DBRootPassword=`echo $DBRootPassword | sed -e 's/^"//' -e 's/"$//'`
DBUser=$(aws ssm get-parameters --region us-east-1 --names /HDN/Wordpress/DBUser --query Parameters[0].Value)
DBUser=`echo $DBUser | sed -e 's/^"//' -e 's/"$//'`
DBName=$(aws ssm get-parameters --region us-east-1 --names /HDN/Wordpress/DBName --query Parameters[0].Value)
DBName=`echo $DBName | sed -e 's/^"//' -e 's/"$//'`
DBEndpoint=$(aws ssm get-parameters --region us-east-1 --names /HDN/Wordpress/DBEndpoint --query Parameters[0].Value)
DBEndpoint=`echo $DBEndpoint | sed -e 's/^"//' -e 's/"$//'`
yum -y update
yum -y upgrade
yum install -y mariadb-server httpd wget
amazon-linux-extras install -y lamp-mariadb10.2-php7.2 php7.2
amazon-linux-extras install epel -y
yum install stress -y
systemctl enable httpd
systemctl start httpd
wget http://wordpress.org/latest.tar.gz -P /var/www/html
cd /var/www/html
tar -zxvf latest.tar.gz
cp -rvf wordpress/* .
rm -R wordpress
rm latest.tar.gz
sudo cp ./wp-config-sample.php ./wp-config.php
sed -i "s/'database_name_here'/'$DBName'/g" wp-config.php
sed -i "s/'username_here'/'$DBUser'/g" wp-config.php
sed -i "s/'password_here'/'$DBPassword'/g" wp-config.php
sed -i "s/'localhost'/'$DBEndpoint'/g" wp-config.php
usermod -a -G apache ec2-user
chown -R ec2-user:apache /var/www
chmod 2775 /var/www
find /var/www -type d -exec chmod 2775 {} \;
find /var/www -type f -exec chmod 0664 {} \;
On this stage create Load Balancer
Move to the EC2 console https://console.aws.amazon.com/ec2/v2/home?region=us-east-1#Home:
Click Load Balancers under Load Balancing
Click Create Load Balancer
Click Create under Application Load Balancer
Under name enter HDNWORDPRESSALB
Ensure internet-facing is selected
ensure ipv4 selected for IP Address type
On Network mapping, under Mappings for VPC ensure HDNVPC is selected
Check boxes next to us-east-1a, us-east-1b and us-east-1c
Select sn-pub-A, sn-pub-B and sn-pub-C for each.
Under Security Groups
Check Select an existing security group and select HDNVPC-SGLoadBalancer it will have some random at the end and thats ok.
Unselect 'default VPC'
Under Listeners HTTP and 80 should be selected for Load Balancer Protocol and Load Balancer Port
Click Next: Configure Routing
for Target Group choose New Target Group
for Name choose HDNWORDPRESSALBTG
for Target Type choose Instance
For Protocol choose HTTP
For Port choose 80
Under Health checks for Protocol choose HTTP and for Path choose /
Click Next: Register Targets
We won't register any right now, click Next: Review
Click Create
Click on the HDNWORDPRESSALB link
Scroll down and copy the DNS Name into your clipboard
Now Create another parameter store
Set Name as /HDN/Wordpress/ALBDNSNAME Under Description enter DNS Name of the Application Load Balancer for wordpress
set Standardset Stringsettext
for Value set the DNS name of the load balance you copied into your clipboard Click Create Parameter