initial commit

.gitlab-ci.yml

+image: alpine:latest
+
+variables:
+  TERRAFORM_URL: "https://releases.hashicorp.com/terraform/0.7.1/terraform_0.7.1_linux_amd64.zip"
+
+before_script:
+  - apk update && apk add ca-certificates && update-ca-certificates && apk add openssl
+  - wget -O /tmp/terraform.zip $TERRAFORM_URL
+  - unzip /tmp/terraform.zip -d /usr/local/bin 
+
+test:
+  script: terraform validate

README.md

+tf_mod_aws_asg
+==============
+A Terraform module for creating an auto scaling group and it's dependencies. 
+The module generates the launch configuration, the auto scaling group and two autoscaling policies. 
+
+1.) Adding a module resource to your template, e.g. `main.tf`
+
+```
+module "asg" {
+  source = "../../../../steamhaus/tf_mod_aws_ec2"
+
+  lc_name = "${var.name}-app-lc-"
+  ami_id = "${data.aws_ami.app.id}"
+  iam_instance_profile = "${module.cloudwatch_logs.profile_id}"
+  key_name = "Bastion"
+  security_groups = ["${aws_security_group.app.id}"]
+  user_data = "${data.template_file.userdata_app.rendered}"
+
+  asg_name = "${var.name}-app"
+  load_balancers = ["${module.elb.elb_id}"]
+  vpc_zone_identifier = ["${module.vpc.private_subnets}"]
+}
+```
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main.tf

+#############################################################################################################
+# Variables
+#############################################################################################################
+# Launch Configuration Variables
+variable "lc_name" {}
+variable "ami_id" {
+  description = "The AMI to use with the launch configuration"
+}
+variable "instance_type" {
+  default = "m3.medium"
+}
+variable "iam_instance_profile" {
+  description = "The IAM role the launched instance will use"
+}
+variable "key_name" {
+  description = "The SSH public key name (in EC2 key-pairs) to be injected into instances"
+  default = "Bastion"
+}
+variable "security_groups" {
+  description = "ID of SG the launched instance will use"
+  type = "list"
+}
+variable "user_data" {
+  description = "The path to a file with user_data for the instances"
+}
+
+# Auto-Scaling Group
+variable "asg_name" {}
+variable "asg_minimum_number_of_instances" {
+  description = "The minimum number of instances we want in the ASG"
+  default = "2"
+}
+variable "asg_maximum_number_of_instances" {
+  description = "The maximum number of instances we want in the ASG"
+  default = "2"
+}
+variable "asg_desired_number_of_instances" {
+  description = "The desired number of instances we want in the ASG"
+  default = "2"
+}
+variable "health_check_grace_period" {
+  description = "Number of seconds for a health check to time out"
+  default = 300
+}
+variable "health_check_type" {
+  description = "The health check used by the ASG to determine health"
+  default = "ELB"
+}
+variable "load_balancers" {
+  description = "A list of ELB names the ASG should associate instances with"
+  type = "list"
+}
+variable "vpc_zone_identifier" {
+  type = "list"
+}
+
+# Auto-Scaling policies
+variable "scale_up_scaling_adjsutment" {
+  default = "100"
+}
+variable "scale_up_cooldown" {
+  default = "60"
+}
+variable "scale_down_scaling_adjsutment" {
+  default = "-50"
+}
+variable "scale_down_cooldown" {
+  default = "120"
+}
+
+
+resource "aws_launch_configuration" "default" {
+  lifecycle { create_before_destroy = true }
+  name_prefix          = "${var.lc_name}"
+  image_id             = "${var.ami_id}"
+  instance_type        = "${var.instance_type}"
+  key_name             = "${var.key_name}"
+  iam_instance_profile = "${var.iam_instance_profile}"
+  security_groups      = ["${var.security_groups}"]
+  user_data            = "${var.user_data}"
+}
+
+resource "aws_autoscaling_group" "default" {
+  lifecycle { create_before_destroy = true }
+  name                      = "${var.asg_name}"
+  launch_configuration      = "${aws_launch_configuration.default.name}"
+  load_balancers            = ["${var.load_balancers}"]
+  vpc_zone_identifier       = ["${var.vpc_zone_identifier}"]
+  min_elb_capacity          = "${var.asg_minimum_number_of_instances}"
+  min_size                  = "${var.asg_minimum_number_of_instances}"
+  max_size                  = "${var.asg_maximum_number_of_instances}"
+  desired_capacity          = "${var.asg_desired_number_of_instances}"
+  health_check_grace_period = "${var.health_check_grace_period}"
+  health_check_type         = "${var.health_check_type}"
+  tag {
+    key                 = "Name"
+    value               = "${var.asg_name}"
+    propagate_at_launch = true
+  }
+  tag {
+    key                 = "Launch config"
+    value               = "${aws_launch_configuration.default.name}"
+    propagate_at_launch = true
+  }
+}
+
+resource "aws_autoscaling_policy" "scale-up" {
+  name                   = "${var.asg_name}-scale-up"
+  adjustment_type        = "PercentChangeInCapacity"
+  scaling_adjustment     = "${var.scale_up_scaling_adjsutment}"
+  cooldown               = "${var.scale_up_cooldown}"
+  autoscaling_group_name = "${aws_autoscaling_group.default.name}"
+}
+
+resource "aws_autoscaling_policy" "scale-down" {
+  name                   = "${var.asg_name}-scale-down"
+  adjustment_type        = "PercentChangeInCapacity"
+  scaling_adjustment     = "${var.scale_down_scaling_adjsutment}"
+  cooldown               = "${var.scale_down_cooldown}"
+  autoscaling_group_name = "${aws_autoscaling_group.default.name}"
+}
+
+#############################################################################################################
+# Outputs
+#############################################################################################################
+output "launch_config_id" {
+    value = "${aws_launch_configuration.default.id}"
+}
+output "asg_id" {
+    value = "${aws_autoscaling_group.default.id}"
+}
+output "asg_name" {
+    value = "${aws_autoscaling_group.default.name}"
+}
+output "autoscaling_policy_scale_up_arn" {
+  value = "${aws_autoscaling_policy.scale-up.arn}"
+}
+output "autoscaling_policy_scale_down_arn" {
+  value = "${aws_autoscaling_policy.scale-down.arn}"
+}
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