Add demo-app autoscaling group

modules/app/main.tf

@@ -0,0 +1,89 @@
+resource "aws_security_group" "this" {
+  name = "demo-app-autoscaling-group-sg"
+
+  vpc_id = var.VPC_ID
+
+  ingress {
+    description = "Self all"
+    from_port   = 0
+    to_port     = 65535
+    protocol    = "tcp"
+    self        = true
+  }
+
+  ingress {
+    description = "SSH"
+    from_port   = 22
+    to_port     = 22
+    protocol    = "tcp"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+
+  ingress {
+    description = "HTTP"
+    from_port   = 80
+    to_port     = 80
+    protocol    = "tcp"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+
+  ingress {
+    description = "HTTPS"
+    from_port   = 443
+    to_port     = 443
+    protocol    = "tcp"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+
+  egress {
+    from_port   = 0
+    to_port     = 0
+    protocol    = "-1"
+    cidr_blocks = ["0.0.0.0/0"]
+  }
+}
+
+data "template_file" "bootstrap" {
+  template = file("${path.module}/resources/bootstrap.sh")
+}
+
+resource "aws_launch_configuration" "this" {
+  name = "demo-app-launch-configuration"
+
+  image_id      = var.EC2_IMAGE_ID
+  instance_type = var.EC2_TYPE
+
+  key_name = var.EC2_KEY_NAME
+  security_groups = [aws_security_group.this.id]
+  user_data = data.template_file.bootstrap.rendered
+
+  lifecycle {
+    create_before_destroy = true
+  }
+}
+
+resource "aws_autoscaling_group" "this" {
+  name = "demo-app-autoscaling-group"
+
+  min_size         = var.ASG_MIN_SIZE
+  max_size         = var.ASG_MAX_SIZE
+
+  launch_configuration      = aws_launch_configuration.this.name
+  vpc_zone_identifier       = var.VPC_SUBNETS_IDS
+  health_check_type         = "ELB"
+  health_check_grace_period = "90"
+
+  tag {
+    key                 = "Name"
+    value               = "demo-app-instance"
+    propagate_at_launch = true
+  }
+}
+
+resource "aws_autoscaling_policy" "this" {
+  name                   = "demo-app-autoscaling-policy"
+  scaling_adjustment     = 1
+  adjustment_type        = "ChangeInCapacity"
+  cooldown               = 300
+  autoscaling_group_name = aws_autoscaling_group.this.name
+}

modules/app/resources/bootstrap.sh

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+#!/bin/bash
+
+yum update -y
+amazon-linux-extras install docker
+service docker start
+usermod -a -G docker ec2-user
+chkconfig docker on
+
+docker run \
+  -p 80:80 \
+  --restart unless-stopped \
+  nginxdemos/hello

modules/app/variables.tf

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+# VPC
+variable "VPC_ID" {
+  type = string
+}
+
+variable "VPC_SUBNETS_IDS" {
+  type = list(string)
+}
+
+# EC2
+variable "EC2_IMAGE_ID" {
+  type = string
+}
+
+variable "EC2_TYPE" {
+  type = string
+}
+
+variable "EC2_KEY_NAME" {
+  type = string
+}
+
+# ASG
+variable "ASG_MIN_SIZE" {
+  type = number
+}
+
+variable "ASG_MAX_SIZE" {
+  type = number
+}