Automating High Availability and Scalability with Terraform Load Balancing in the Cloud"
Published: 2023-07-20 19:09:18

**Step 1: Set up the Terraform Project**

1. - Install Terraform: Download and install Terraform on your local machine from the official website: https://www.terraform.io/downloads.html
2. - Create a directory for your Terraform project.
3. - Initialize Terraform: Inside the project directory, create a new file named main.tf and add the following code to define the provider:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/rsogw1s2htko1rslwfvf.jpg)
**Step 2: Create the VPC**

1. -  create the VPC and subnets in the same main.tf file

**Setting up Internet Gateway and Route Table:**

1. - Create a new file named internet_gateway.tf and add the following code to set up the internet gateway and route table:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ji6gwvwo6w5ld5t2wlk2.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/p8md73r5tdasj1tmaq5d.png)
**Configuring Security Groups**:

1. - Create a new file named security_groups.tf and add the following code to configure security groups for the load balancer and instances:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/gp82fr95qbn2r6wsuugd.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/kf83qp4iqkqmep115dce.png)
We define a security group alb_sg for the Application Load Balancer (ALB), allowing incoming traffic on port 80 from any source (0.0.0.0/0).

1. - We create a security group instance_sg for the EC2 instances, allowing incoming traffic on port 80 only from the security group of the ALB. This ensures that the instances can receive traffic from the load balancer while maintaining security.

**Generating and Configuring SSH Keys:**
Open a terminal on your local machine.

To generate an SSH key pair, run the following command:
1. - ssh-keygen 

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/b2kmybo2ee50ghq7l8hf.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/r2fwki7rfgfyl7bu9r0x.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/6at08hkd8rc9wfegwftp.png)
Launching EC2 Instancess:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/9klk2jx4mqz86kgsf95f.png)

**Configuring the Load Balancer,TargetGroup and Listerner:**

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/47fs1y4pgcu9lwyqk5pq.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/y8c2tcr4sih7mz1ffh7v.png)
**Result:**
After successfully applying the Terraform configuration, you will have a fully functional and highly available web application infrastructure on AWS. Let's take a look at what you've achieved:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/s0iazegs5zcpzavivnju.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/0ssdcvsbq3zu9ekc81oa.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/rfgqge7snjuoy5rj5sps.png)

**Upon refreshing the web application, the ALB distributes incoming requests to registered EC2 instances, ensuring high availability and scalability. Auto Scaling launches additional instances if needed, maintaining smooth traffic distribution.**


![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/bq01u5xwruj9tsg19use.png)
![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/drecrstlf1cobnweihn5.png)