Create Auto Scaling resources by using Terraform

Resources used

Create Auto Scaling resources

In this example, you will create Auto Scaling resources, including a scaling group, a scaling configuration, and a scaling rule.

1. Create a working directory, create a configuration file named main.tf, and then copy the following code into main.tf.

   variable "region" {
     default = "cn-heyuan"
   }
   variable "instance_type" {
     default = "ecs.hfc7.xlarge"
   }
   variable "image_id" {
     default = "aliyun_2_1903_x64_20G_alibase_20210120.vhd"
   }
   variable "zone_id" {
     default = "cn-heyuan-b"
   }
   provider "alicloud" {
     region = var.region
   }
   # Create a VPC.
   resource "alicloud_vpc" "vpc" {
     vpc_name   = "tf-test-vpc-wjt"
     cidr_block = "172.16.0.0/12" # Specify the private CIDR block for the VPC.
   }
   # Create a vSwitch.
   resource "alicloud_vswitch" "vsw" {
     vpc_id       = alicloud_vpc.vpc.id
     cidr_block   = "172.16.0.0/21" # Specify the private CIDR block for the vSwitch.
     zone_id      = var.zone_id     # Select the zone for the vSwitch.
     vswitch_name = "tf-test-vswitch-wjt"
   }
   # Create a security group.
   resource "alicloud_security_group" "security" {
     name        = "tf_test_security"
     description = "New security group"
     vpc_id      = alicloud_vpc.vpc.id
   }
   # Add a security group rule that allows traffic from all IP addresses.
   resource "alicloud_security_group_rule" "allow_all_tcp" {
     type              = "ingress"
     ip_protocol       = "tcp"
     nic_type          = "intranet"
     policy            = "accept"
     port_range        = "1/65535"
     priority          = 1
     security_group_id = alicloud_security_group.security.id
     cidr_ip           = "0.0.0.0/0"
   }
   # This example creates a scaling group with a maximum of 100 instances.
   resource "alicloud_ess_scaling_group" "group" {
     scaling_group_name = "tf_test_scalinggroup"
     min_size           = 0
     max_size           = 100
     vswitch_ids        = [alicloud_vswitch.vsw.id]
   }
   # This example creates a scaling configuration for ECS instances.
   resource "alicloud_ess_scaling_configuration" "configuration" {
     scaling_group_id           = alicloud_ess_scaling_group.group.id
     instance_type              = var.instance_type
     image_id                   = var.image_id
     security_group_id          = alicloud_security_group.security.id
     scaling_configuration_name = "tf_test_scalingconfiguration"
     system_disk_category       = "cloud_essd"
     spot_strategy              = "SpotWithPriceLimit"
     active                     = true
     force_delete               = true
   }
   # Create a scaling rule.
   resource "alicloud_ess_scaling_rule" "rule" {
     scaling_group_id = alicloud_ess_scaling_group.group.id
     adjustment_type  = "QuantityChangeInCapacity"
     adjustment_value = 1
   }

2. Run the following command to initialize the Terraform runtime environment.

   terraform init

   The following output indicates that the initialization is successful.

   Initializing the backend...
   Initializing provider plugins...
   - Checking for available provider plugins...
   - Downloading plugin for provider "alicloud" (hashicorp/alicloud) 1.90.1...
   ...
   You may now begin working with Terraform. Try running "terraform plan" to see
   any changes that are required for your infrastructure. All Terraform commands
   should now work.
   If you ever set or change modules or backend configuration for Terraform,
   rerun this command to reinitialize your working directory. If you forget, other
   commands will detect it and remind you to do so if necessary.

3. Create an execution plan and preview the changes.

   terraform plan

4. Run the following command to create the resources.

   terraform apply

   When prompted, type yes and press Enter. Wait for the command to finish. The following output indicates that the Auto Scaling resources are created.

   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
   ...
   alicloud_security_group_rule.allow_all_tcp: Creation complete after 0s [id=sg-f8z1mes******:ingress:tcp:1/65535:intranet:0.0.0.0/0:accept:1]
   alicloud_vswitch.vsw: Creation complete after 3s [id=vsw-f8ztgc4******]
   alicloud_ess_scaling_group.group: Creating...
   alicloud_ess_scaling_group.group: Creation complete after 2s [id=asg-f8z9mo******]
   ...
   Apply complete! Resources: 7 added, 0 changed, 0 destroyed.

5. Verify the results

   Terraform show

   Run the following command to view the details of the resources created by Terraform:

   terraform show

   D:\tf>terraform show
   # alicloud_ess_scaling_configuration.configuration:
   resource "alicloud_ess_scaling_configuration" "configuration" {
       active                         = true
       credit_specification           = null
       force_delete                   = true
       host_name                      = null
       id                             = "xxx"
       image_id                       = "aliyun_2_1903_x64_20G_alibase_20210120.vhd"
       image_name                     = null
       instance_name                  = "ESS-Instance"
       instance_type                  = "ecs.hfc7.xlarge"
       internet_charge_type           = "PayByBandwidth"
       internet_max_bandwidth_in      = 0
       internet_max_bandwidth_out     = 0
       key_name                       = null
       override                       = false
       password_inherit                = false
       resource_group_id              = null
       role_name                      = null
       scaling_configuration_name     = "tf_test_scalingconfiguration"
       scaling_group_id               = "xxx"
       security_group_id              = "xxx"
       spot_strategy                  = "SpotWithPriceLimit"
       ...
       system_disk_auto_snapshot_policy_id = null
       system_disk_category           = "cloud_essd"
       system_disk_description        = null
       system_disk_encrypted          = false
       system_disk_name               = null
       system_disk_performance_level  = null
       system_disk_size               = 0
   }
   # alicloud_ess_scaling_group.group:
   resource "alicloud_ess_scaling_group" "group" {
       allocation_strategy                    = null
       az_balance                             = false
       default_cooldown                       = 300
       desired_capacity                       = 0
       group_deletion_protection              = false
       group_type                             = "ECS"
       health_check_type                      = "ECS"
       id                                     = "asg-xxx"
       launch_template_id                     = null
       launch_template_version                = null
       max_size                               = 100
       min_size                               = 0
       multi_az_policy                        = "PRIORITY"
       on_demand_base_capacity                = 0
       on_demand_percentage_above_base_capacity = 0
       removal_policies                       = [
           "OldestScalingConfiguration",
           "OldestInstance",
       ]
       resource_group_id                      = "xxx"
       scaling_group_name                     = "tf_test_scalinggroup"
       scaling_policy                         = "release"
       spot_allocation_strategy               = null
       spot_instance_remedy                   = false
       vswitch_ids                            = [
           "vsw-f8ztgc4ad3e7ft9evy38z",
       ]
   }

   Auto Scaling console

   Log on to the Auto Scaling console to view the scaling group that you created.

   In the top navigation bar, select China (Heyuan) from the region selector. On the Scaling Groups page, find the scaling group named tf_test_scalinggroup and confirm that its status is Disabled, its type is ECS, and its maximum number of instances is 100.

Clean up resources

When you no longer need the resources created and managed by Terraform, run the following command to destroy them. For more information about terraform destroy, see Common commands.

terraform destroy

variable "region" {
  default = "cn-heyuan"
}
variable "instance_type" {
  default = "ecs.hfc7.xlarge"
}
variable "image_id" {
  default = "aliyun_2_1903_x64_20G_alibase_20210120.vhd"
}
variable "zone_id" {
  default = "cn-heyuan-b"
}
provider "alicloud" {
  region = var.region
}
# Create a VPC.
resource "alicloud_vpc" "vpc" {
  vpc_name   = "tf-test-vpc-wjt"
  cidr_block = "172.16.0.0/12" # Specify the private CIDR block for the VPC.
}
# Create a vSwitch.
resource "alicloud_vswitch" "vsw" {
  vpc_id       = alicloud_vpc.vpc.id
  cidr_block   = "172.16.0.0/21" # Specify the private CIDR block for the vSwitch.
  zone_id      = var.zone_id     # Select the zone for the vSwitch.
  vswitch_name = "tf-test-vswitch-wjt"
}
# Create a security group.
resource "alicloud_security_group" "security" {
  name        = "tf_test_security"
  description = "New security group"
  vpc_id      = alicloud_vpc.vpc.id
}
# Add a security group rule that allows traffic from all IP addresses.
resource "alicloud_security_group_rule" "allow_all_tcp" {
  type              = "ingress"
  ip_protocol       = "tcp"
  nic_type          = "intranet"
  policy            = "accept"
  port_range        = "1/65535"
  priority          = 1
  security_group_id = alicloud_security_group.security.id
  cidr_ip           = "0.0.0.0/0"
}
# This example creates a scaling group with a maximum of 100 instances.
resource "alicloud_ess_scaling_group" "group" {
  scaling_group_name = "tf_test_scalinggroup"
  min_size           = 0
  max_size           = 100
  vswitch_ids        = [alicloud_vswitch.vsw.id]
}
# This example creates a scaling configuration for ECS instances.
resource "alicloud_ess_scaling_configuration" "configuration" {
  scaling_group_id           = alicloud_ess_scaling_group.group.id
  instance_type              = var.instance_type
  image_id                   = var.image_id
  security_group_id          = alicloud_security_group.security.id
  scaling_configuration_name = "tf_test_scalingconfiguration"
  system_disk_category       = "cloud_essd"
  spot_strategy              = "SpotWithPriceLimit"
  active                     = true
  force_delete               = true
}
# Create a scaling rule.
resource "alicloud_ess_scaling_rule" "rule" {
  scaling_group_id = alicloud_ess_scaling_group.group.id
  adjustment_type  = "QuantityChangeInCapacity"
  adjustment_value = 1
}