An introduction to Hashicorp's Terraform.

1. Terraform
Sonia Hamilton
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2. Provisioning
instances
storage
dns
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3. In Relation To...
Puppet, Salt
Boto, Fog
CloudFormation
Vagrant?
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4. Features
execution plans
dependencies
state
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5. Example Providers
AWS
Heroku
Google Cloud
DNSimple
no VCloud, yet...
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6. Terraform and Go
Terraform is written in Go (golang)
dev version
http://blog.snowfrog.net/2014/12/04/building-the-development-
version-of-terraform/
http://bit.ly/1vNjuIU
docs -- grep
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7. Using a Provider
provider "aws" {
access_key = "ACCESS_KEY_HERE"
secret_key = "SECRET_KEY_HERE"
region = "us-east-1"
}
resource "aws_instance" "example" {
ami = "ami-408c7f28"
instance_type = "t1.micro"
}
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8. Terraform Plan
$ terraform plan
...
+ aws_instance.example
ami: "" => "ami-408c7f28"
availability_zone: "" => "<computed>"
instance_type: "" => "t1.micro"
key_name: "" => "<computed>"
private_dns: "" => "<computed>"
private_ip: "" => "<computed>"
public_dns: "" => "<computed>"
public_ip: "" => "<computed>"
security_groups: "" => "<computed>"
subnet_id: "" => "<computed>"
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9. Terraform Apply
$ terraform apply
aws_instance.example: Creating...
ami: "" => "ami-408c7f28"
instance_type: "" => "t1.micro"
Apply complete! Resources: 1 added, 0 changed, 0 destroyed.
...
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10. terraform.tfstate
JSON file
TerraformShow
$ terraform show
aws_instance.example:
id = i-e60900cd
ami = ami-408c7f28
availability_zone = us-east-1c
instance_type = t1.micro
key_name =
private_dns = domU-12-31-39-12-38-AB.compute-1.internal
private_ip = 10.200.59.89
public_dns = ec2-54-81-21-192.compute-1.amazonaws.com
public_ip = 54.81.21.192
security_groups.# = 1
security_groups.0 = default
subnet_id =
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11. Plan/Apply - Video
provider "aws" {
access_key = "AKIA................"
secret_key = "puOt...................................."
region = "ap-southeast-2"
}
resource "aws_instance" "example" {
key_name = "sonia" # AWS keypair name
ami = "ami-9b0b62a1" # Ubuntu 14.04
instance_type = "t1.micro"
}
demo01
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12. Changing Infrastructure
Edit
resource "aws_instance" "example" {
ami = "ami-aa7ab6c2" # NEW AMI
instance_type = "t1.micro"
}
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13. Changing Infrastructure
Plan
$ terraform plan
...
-/+ aws_instance.example
ami: "ami-408c7f28" => "ami-aa7ab6c2" (forces new resource)
availability_zone: "us-east-1c" => "<computed>"
...
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14. Changing Infrastructure
Apply
$ terraform apply
aws_instance.example: Destroying...
aws_instance.example: Modifying...
ami: "ami-408c7f28" => "ami-aa7ab6c2"
Apply complete! Resources: 0 added, 1 changed, 1 destroyed.
...
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15. Destroy Infrastructure
Plan
$ terraform plan -destroy
...
- aws_instance.example
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16. Destroy
$ terraform destroy
aws_instance.example: Destroying...
Apply complete! Resources: 0 added, 0 changed, 1 destroyed.
...
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17. Changing Infrastructure - Video
provider "aws" {
access_key = "AKIA................"
secret_key = "puOt...................................."
region = "ap-southeast-2"
}
resource "aws_instance" "example" {
key_name = "sonia" # AWS keypair name
ami = "ami-950b62af" # Ubuntu 14.04
instance_type = "t2.small" # CHANGED
}
demo02
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18. Resource Dependencies
multiple providers
multiple resource types
do x before y, and y needs x's ip address
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19. Resource Dependencies
resource "aws_eip" "ip" {
instance = "${aws_instance.example.id}" # IMPLICIT
}
Plan
$ terraform plan
...
+ aws_eip.ip
instance: "" => "${aws_instance.example.id}"
private_ip: "" => "<computed>"
public_ip: "" => "<computed>"
+ aws_instance.example
ami: "" => "ami-aa7ab6c2"
...
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20. Resource Dependencies
Apply
aws_instance.example: Creating...
ami: "" => "ami-aa7ab6c2"
instance_type: "" => "t1.micro"
aws_eip.ip: Creating...
instance: "" => "i-0e737b25"
Apply complete! Resources: 2 added, 0 changed, 0 destroyed.
Run order is different from output order.
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21. Explicit Dependencies
resource "aws_eip" "ip" {
instance = "${aws_instance.example.id}"
depends_on = ["aws_instance.example"]
}
terraformgraph
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22. Dependencies - Video
provider "aws" {
access_key = "AKIA................"
secret_key = "puOt...................................."
region = "ap-southeast-2"
}
resource "aws_instance" "example" {
key_name = "sonia" # AWS keypair name
ami = "ami-9b0b62a1" # Ubuntu 14.04
instance_type = "t1.micro"
}
resource "aws_eip" "example_eip" {
instance = "${aws_instance.example.id}"
}
demo03
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23. Provisioners
connection
file
local-exec
remote-exec
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24. Connection/File Provisioner - Video
provider "aws" {
access_key = "AKIA................"
secret_key = "puOt...................................."
region = "ap-southeast-2"
}
resource "aws_instance" "example" {
key_name = "sonia" # AWS keypair name
ami = "ami-9b0b62a1" # Ubuntu 14.04
instance_type = "t1.micro"
connection {
user = "ubuntu"
host = "${aws_instance.example.public_ip}"
key_file = "../include/sonia.pem"
}
provisioner "file" {
source = "bootstrap"
destination = "/var/tmp"
}
}
demo04
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25. Exec Provisioners - Video
provider "aws" {
access_key = "AKIA................"
secret_key = "puOt...................................."
region = "ap-southeast-2"
}
resource "aws_instance" "example" {
key_name = "sonia" # AWS keypair name
ami = "ami-9b0b62a1" # Ubuntu 14.04
instance_type = "t1.micro"
connection {
user = "ubuntu"
host = "${aws_instance.example.public_ip}"
key_file = "../include/sonia.pem"
}
provisioner "local-exec" {
command = "echo ${aws_instance.example.public_ip} > ip.txt"
}
provisioner "remote-exec" {
inline = [ "sudo locale-gen en_AU.UTF-8" ]
}
provisioner "remote-exec" {
script = "script1.sh"
}
}
demo05
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26. 'Advanced'
input, output variables
modules
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27. Input Variables
Commonly named variables.tf, uses all *.tf files.
variable "access_key" {}
variable "secret_key" {}
variable "region" {
default = "us-east-1"
}
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28. Using Variables
provider "aws" {
access_key = "${var.access_key}"
secret_key = "${var.secret_key}"
region = "${var.region}"
}
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29. Assigning Variables
CommandLine
$ terraform apply
-var 'access_key=foo'
-var 'secret_key=bar'
File
terraform.tfvars or use -var-file
access_key = "foo"
secret_key = "bar"
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30. Outputs Variables
Defining
output "ip" {
value = "${aws_eip.ip.public_ip}"
}
Viewing
$ terraform apply
...
Apply complete! Resources: 0 added, 0 changed, 0 destroyed.
Outputs:
ip = 50.17.232.209
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31. Modules
Create
$ mkdir child
$ touch child/main.tf
Use
module "child" {
source = "./child"
}
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32. Module Parameters - Input
Caller
module "child" {
source = "./child"
memory = "1G"
}
Child
variable "memory" {}
resource "aws_db_instance" "default" {
...
allocated_storage = "${var.memory}"
...
}
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33. Module Parameters - Output
Child
output "result" {
value = "${foo.region}-${bar.city}"
}
Caller
module "child" { ... }
resource "aws_instance" "web" {
...
tags { Location = "${module.child.result}" }
...
}
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34. Questions
Sonia Hamilton
sonia@snowfrog.net
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