calvin-puram / devopsng-terraform Goto Github PK

• Using terraform to create infrastrucutre on AWS
• I Deploy a single instance on AWS using the items below:

1. VPC

2. Subnet inside VPC

3. Internet gateway associated with VPC

4. Route Table inside VPC with a route that directs internet-bound traffic to the internet gateway

5. Route table association with our subnet to make it a public subnet

6. Security group inside VPC

7. Key pair used for SSH access

8. EC2 instance inside our public subnet with an associated security group and generated a key pair

Using terraform I setup an immutable infrastructure which can be destroyed and created using single command.

terraform init : Initialize a Terraform working directory

terraform plan : Generate and show an execution plan

terraform apply : Builds or changes infrastructure

terraform destroy : Destroy Terraform-managed infrastructure.

Variables are read from variables.tf file. If not specified in that file, parameters are read from following places :

1. Command line flags

2. File named terraform.tfvars, if name is something else can be provided using command line flag

3. Environment variables

4. UI input (only supports String variables)

Screenshot of terraform plan

Screenshot of terraform apply

Screenshot of running instance

To create multiple ec2 instance in AWS account using terraform code you can edit the variables file.

  variable "instance_count" {
  description = "Number of instances to be created"
  default     = "1"
  type = string
}

Screenshot of terraform plan

Screenshot of terraform apply

Screenshot of running instance

This folder ("webservers-clusters") is an example of using ELB Elastic Load Balancing with ASG Auto Scaling Group to provide highly available and efficient web servers

I use ASG to launch a cluster of EC2 Instances, replacing failed Instances, and adjusting the size of the cluster in response to load.

• ASG distributes the EC2 instances across multiple availability zones
  • each AWS account has access to different set of Availability zones, in this repo, i've choosed all availability zones available in my account

After deploying the ASG you'll have serveral different servers, each with its own ip address, but you need to give your end users only a single IP to hit, and for this I deploy a load balancer to distribute traffic accross the servers and to give your end users a single dns name which is the the load balancer dns name.

Screenshot of terraform plan

Screenshot of terraform apply

Screenshot of running instance