codevally / terraform-bluegreen

Terraform module to setup blue / green deployments

terraform-bluegreen

Terraform module to setup blue / green deployments

##blue-green

Variables

See the blue-green/variables.tf file.

Outputs

• blue_asg_id: (Number) blue autoscaling group id
• green_asg_id: (Number) green autoscaling group id

Example

module "bluegreen" {
  source = "github.com/skyscrapers/terraform-bluegreen//blue-green"
  project = "example"
  name = "app"
  environment = "production"
  blue_ami = "ami-blabla"
  green_ami = "ami-blabla"
  instance_type = "t2.micro"
  loadbalancers = []
  blue_max_size = "5"
  blue_min_size = "2"
  blue_desired_capacity = "2"
  green_max_size = "0"
  green_min_size = "0"
  green_desired_capacity = "0"
  security_groups = []
}

cpu-scaling

Terraform module to setup alarms and autoscaling triggers for autoscaling

Variables

See the cpu-scaling/variables.tf file.

Outputs

/

Example

module "cpu-scaling" {
  source = "github.com/skyscrapers/terraform-bluegreen//cpu-scaling"
  project = "example"
  name = "app"
  environment = "production"
  autoscaling_group_name = ["my_asg_name1","my_asg_name2"]
}

Blue-green deployments

The bluegreen.py script performs a bluegreen deployment of the selected terraform stack. It only works with Python 2.7. The blue-green deployment script expects certain inputs and outputs in the Terraform project you want to deploy in a blue-green fashion.

Required outputs:

output "blue_asg_id" {
  value = "${module.<blue-green-module-name>.blue_asg_id}"
}

output "green_asg_id" {
  value = "${module.<blue-green-module-name>.green_asg_id}"
}

Required variables:

variable "blue_max_size" {
  description = "max instances blue"
}

variable "blue_min_size" {
  description = "min instances blue"
}

variable "blue_desired_capacity" {
  description = "desired instances blue"
}

variable "green_max_size" {
  description = "max instances green"
}

variable "green_min_size" {
  description = "min instances green"
}

variable "green_desired_capacity" {
  description = "desired instances green"
}

variable "blue_ami" {
  description = "blue ami"
}

variable "green_ami" {
  description = "green ami"
}

These input variables need to be assigned to your module. Make sure you do a terraform refresh to be sure that the terraform outputs are saved in the Terraform state file.

Usage

First you need to install the requirements:

pip install -r requirements.txt

Run ./bluegreen.py --help to see the available options.

Example:

./bluegreen.py -f stacks/test/application -a ami-xxxx -c apply -t 500