Table of Contents
#Introduction
In this tutorial, How to deploy cluster web servers use Terraform. Now, let’s go Terraform deploy cluster web servers in Auto Scaling Group
- AWS auto scaling Group: Min = 2, Max = 10 and desired_capacity =3
- User user_data and create a script to install Nginx webserver on amazon linux 2.
- Auto Scaling Group: Scaling Policy – Target Tracking policy
- Security group ingress rule to allow access web server from my laptop ?
Structure folder and files Terraform deploy cluster web servers in Auto Scaling Group
Created Cluster_WebServer_ASG folder contains files as below:
asg_config.tf
auto_scale_group.tf
auto_scale_policy.tf
output.tf
provider.tf
securitygroups.tf
variables.tfOn AWS
we created key pair terraform-demo as the picture below
Deploy cluster web servers in Auto Scaling Group
Create a new file asg_config.tf with the content as below
resource aws_launch_configuration "my_config" {
name = "webserver-launch"
image_id = var.ami
instance_type = var.instance_type
security_groups=["${aws_security_group.web_sg.id}"]
key_name = "terraform-demo"
user_data = <<EOF
#!/bin/bash -xe
exec > >(tee /var/log/user-data.log|logger -t user-data -s 2>/dev/console) 2>&1
sudo yum update -y
sudo amazon-linux-extras install nginx1 -y
sudo su -c "/bin/echo 'My Site: DevopsRoles.com' >/usr/share/nginx/html/index.html"
instance_ip=`curl http://169.254.169.254/latest/meta-data/local-ipv4`
sudo su -c "echo $instance_ip >>/usr/share/nginx/html/index.html"
sudo systemctl start nginx
sudo systemctl enable nginx
EOF
}Create a new file auto_scale_group.tf with the content as below
resource "aws_autoscaling_group" "first_asg" {
launch_configuration = aws_launch_configuration.my_config.id
availability_zones = "${var.azs}"
min_size = 2
max_size = 10
desired_capacity = 3
tag {
key = "Name"
value = "terraform-asg"
propagate_at_launch = true
}
}New file auto_scale_policy.tf with the content as below
resource "aws_autoscaling_policy" "my_asg_policy" {
name = "webservers_autoscale_policy"
policy_type = "TargetTrackingScaling"
autoscaling_group_name = aws_autoscaling_group.first_asg.name
target_tracking_configuration {
predefined_metric_specification {
predefined_metric_type = "ASGAverageCPUUtilization"
}
target_value = "75"
}
}Create new a provider.tf the content as below
provider "aws" {
region = var.region
}Create a new file output.tf with the content as below
output "asg_arn" {
value = [ "${aws_autoscaling_group.first_asg.arn}"]
}Create new file variables.tf with the content as below
variable "region" {
description = " Define the AWS region "
default = "us-west-2"
}
variable "server_port" {
description = "http service listen"
default = "80"
}
variable "ssh_port" {
description = "ssh to server"
default = "22"
}
variable "instance_type" {
description = "AWS ec2 instance type"
default="t2.micro"
}
variable "my_public_ip" {
description = "My laptop public IP ..."
default = "116.110.26.150/32"
}
variable "ami" {
description = "amazon machine image"
default = "ami-0c2d06d50ce30b442"
}
variable "azs" {
default = [ "us-west-2a", "us-west-2b", "us-west-2c" ]
}new file securitygroups.tf with the content as below
resource "aws_security_group" "web_sg" {
ingress {
from_port = var.server_port
to_port = var.server_port
protocol = "tcp"
cidr_blocks = [ var.my_public_ip ]
}
ingress {
from_port = var.ssh_port
to_port = var.ssh_port
protocol = "tcp"
cidr_blocks = [ var.my_public_ip ]
}
egress {
from_port = 0
to_port = 0
protocol = "-1"
cidr_blocks = ["0.0.0.0/0"]
}
}First, we run below to initialize, download the plugins and validate the terraform syntax…
terraform init
terraform validateThe output terminal is as follows
Applying a template
$ terraform applyThe output terminal is as below
C:\Users\HuuPV\Desktop\Terraform\Cluster_WebServer_ASG>terraform apply
Terraform used the selected providers to generate the following execution plan. Resource actions are indicated with
the following symbols:
+ create
Terraform will perform the following actions:
# aws_autoscaling_group.first_asg will be created
+ resource "aws_autoscaling_group" "first_asg" {
+ arn = (known after apply)
+ availability_zones = [
+ "us-west-2a",
+ "us-west-2b",
+ "us-west-2c",
]
+ default_cooldown = (known after apply)
+ desired_capacity = 3
+ force_delete = false
+ force_delete_warm_pool = false
+ health_check_grace_period = 300
+ health_check_type = (known after apply)
+ id = (known after apply)
+ launch_configuration = (known after apply)
+ max_size = 10
+ metrics_granularity = "1Minute"
+ min_size = 2
+ name = (known after apply)
+ name_prefix = (known after apply)
+ protect_from_scale_in = false
+ service_linked_role_arn = (known after apply)
+ vpc_zone_identifier = (known after apply)
+ wait_for_capacity_timeout = "10m"
+ tag {
+ key = "Name"
+ propagate_at_launch = true
+ value = "terraform-asg"
}
}
# aws_autoscaling_policy.my_asg_policy will be created
+ resource "aws_autoscaling_policy" "my_asg_policy" {
+ arn = (known after apply)
+ autoscaling_group_name = (known after apply)
+ id = (known after apply)
+ metric_aggregation_type = (known after apply)
+ name = "webservers_autoscale_policy"
+ policy_type = "TargetTrackingScaling"
+ target_tracking_configuration {
+ disable_scale_in = false
+ target_value = 60
+ predefined_metric_specification {
+ predefined_metric_type = "ASGAverageCPUUtilization"
}
}
}
# aws_launch_configuration.my_config will be created
+ resource "aws_launch_configuration" "my_config" {
+ arn = (known after apply)
+ associate_public_ip_address = false
+ ebs_optimized = (known after apply)
+ enable_monitoring = true
+ id = (known after apply)
+ image_id = "ami-0c2d06d50ce30b442"
+ instance_type = "t2.micro"
+ key_name = "terraform-demo"
+ name = "webserver-launch"
+ name_prefix = (known after apply)
+ security_groups = (known after apply)
+ user_data = "e210837ad2017cf0971bc0ed4af86edab9d8a10d"
+ ebs_block_device {
+ delete_on_termination = (known after apply)
+ device_name = (known after apply)
+ encrypted = (known after apply)
+ iops = (known after apply)
+ no_device = (known after apply)
+ snapshot_id = (known after apply)
+ throughput = (known after apply)
+ volume_size = (known after apply)
+ volume_type = (known after apply)
}
+ metadata_options {
+ http_endpoint = (known after apply)
+ http_put_response_hop_limit = (known after apply)
+ http_tokens = (known after apply)
}
+ root_block_device {
+ delete_on_termination = (known after apply)
+ encrypted = (known after apply)
+ iops = (known after apply)
+ throughput = (known after apply)
+ volume_size = (known after apply)
+ volume_type = (known after apply)
}
}
# aws_security_group.web_sg will be created
+ resource "aws_security_group" "web_sg" {
+ arn = (known after apply)
+ description = "Managed by Terraform"
+ egress = [
+ {
+ cidr_blocks = [
+ "0.0.0.0/0",
]
+ description = ""
+ from_port = 0
+ ipv6_cidr_blocks = []
+ prefix_list_ids = []
+ protocol = "-1"
+ security_groups = []
+ self = false
+ to_port = 0
},
]
+ id = (known after apply)
+ ingress = [
+ {
+ cidr_blocks = [
+ "116.110.26.150/32",
]
+ description = ""
+ from_port = 22
+ ipv6_cidr_blocks = []
+ prefix_list_ids = []
+ protocol = "tcp"
+ security_groups = []
+ self = false
+ to_port = 22
},
+ {
+ cidr_blocks = [
+ "116.110.26.150/32",
]
+ description = ""
+ from_port = 80
+ ipv6_cidr_blocks = []
+ prefix_list_ids = []
+ protocol = "tcp"
+ security_groups = []
+ self = false
+ to_port = 80
},
]
+ name = (known after apply)
+ name_prefix = (known after apply)
+ owner_id = (known after apply)
+ revoke_rules_on_delete = false
+ tags_all = (known after apply)
+ vpc_id = (known after apply)
}
Plan: 4 to add, 0 to change, 0 to destroy.
Changes to Outputs:
+ asg_arn = [
+ (known after apply),
]
Do you want to perform these actions?
Terraform will perform the actions described above.
Only 'yes' will be accepted to approve.
Enter a value: yes
aws_security_group.web_sg: Creating...
aws_security_group.web_sg: Creation complete after 8s [id=sg-083d582a5691c56d9]
aws_launch_configuration.my_config: Creating...
aws_launch_configuration.my_config: Creation complete after 2s [id=webserver-launch]
aws_autoscaling_group.first_asg: Creating...
aws_autoscaling_group.first_asg: Still creating... [10s elapsed]
aws_autoscaling_group.first_asg: Still creating... [21s elapsed]
aws_autoscaling_group.first_asg: Still creating... [31s elapsed]
aws_autoscaling_group.first_asg: Still creating... [41s elapsed]
aws_autoscaling_group.first_asg: Creation complete after 45s [id=terraform-20211010125900499300000002]
aws_autoscaling_policy.my_asg_policy: Creating...
aws_autoscaling_policy.my_asg_policy: Creation complete after 2s [id=webservers_autoscale_policy]
Apply complete! Resources: 4 added, 0 changed, 0 destroyed.
Outputs:
asg_arn = [
"arn:aws:autoscaling:us-west-2:633602660500:autoScalingGroup:2b023a9d-a66c-464e-9cb0-80d9eef00e33:autoScalingGroupName/terraform-20211010125900499300000002",
]Result on EC2 AWS
3 Instance EC2
Auto Scaling: Launch configurations
Auto Scaling groups
Conclusion
You have to deploy cluster web servers in the Auto Scaling Group. I hope will this your helpful. Thank you for reading the DevopsRoles page!
