launching aws elb instace using terraform - amazon-ec2

Question

I am new to terraform and aws, all I want to do is launch an aws ec2 instance with elastic load balancer with terraform. I get some of the configuration examples from various sites but don't know what is right way to implement those configurations, what should be the folder structure and everything. I had done it using GUI of aws but not getting much help with terraform.
Here the server should be apache2.
Any help is appreciated.
Thanks in advance

Answer 1

As per your requirement of creating Elastic Loadbalancer, using terraform. You will need to create the following resources.
If you already have the EC2 instance created and just want to attach them to ELB.
Create Target Group
Create ELB
Assign the Target Group to your ELB
Register your existing instance to your Target Group
If you don't have any instance created,
Create Target Group
Create ELB
Assign the Target Group to your ELB
Create Launch Template/Configuration
Create ASG, assign the ELB to ASG
The new instance created through ASG will auto-register to the ELB target group.
Terraform Resource example,
Launch Configuration
resource "aws_launch_configuration" "Your_Launch_Configuration" {
name = "launch_conf_name"
instance_type = "Instance_Type"
image_id = "AMI_image_id"
key_name = "Key_Name"
security_groups = "security_groups_id"
user_data = "User Data"
iam_instance_profile = "Instance IAM Role"
}
Auto Scaling Group
resource "aws_autoscaling_group" "Your_ASG" {
name = "ASG Name"
launch_configuration = aws_launch_configuration.Your_Launch_Configuration.id
max_size = "Max size"
min_size = "Min Size"
desired_capacity = "Desired Capacity"
vpc_zone_identifier = "Your Subnet List"
tags = [{
"key" = "Name"
"value" = "ASG Name"
"propagate_at_launch" = true
}]
health_check_grace_period = "300"
target_group_arns = "set of your ELB target Group"
}
Load Balancer Target Group
resource "aws_load_balancer_target_group" "Your_target_group" {
name = "Target_group_name"
port = "80"
protocol = "HTTP"
vpc_id = "Your_vpcid"
tags = {
name = "Target_group_name"
}
health_check {
enabled = true
interval = 300 # health check interval
protocol = "HTTP"
timeout = 300 # timeout seconds
path = "/" # your health check path
}
}
Load Balancer
resource "aws_load_balancer" "your_load_balancer" {
name = load_balancer_name
load_balancer_type = "application"
internal = true # if not internet facing
subnets = ["List of your subnet id"]
security_groups = ["List of your security group id"]
tags = {
"name" = load_balancer_Target_group_name
}
}
Load Balancer Listner
resource "aws_load_balancer_listener" "your_load_balancer_Listner" {
load_balancer_arn = listner_load_balancer_arn #arn of your load balancer
port = "80"
protocol = "http"
default_action {
target_group_arn = listner_Target_group_arn # arn of your target group
type = "forward"
}
}