terraform.md

Terraform

init

Download zip & unzip into PATH somewhere.

terraform init      # in work directory

mkdir  ~/terraform-plugins      # specify an alternate plugin path
                                # manually copy plugins to here

terraform init -plugin-dir ~/terraform-plugins
    # updates .terraform/plugin_path to point to persistent, shared dir for plugins

plan

-/+ means destroy/create
~ means in place update

apply

plan -destroy

destroy

graph

terraform graph | dot -Tpng  | open -a Preview.app -f

Misc

${aws_instance.example.id}   # get id from aws_instance.example resource

depends_on = ["aws_instance.example"]  # explicit dependency

Provisioners

provisioner "local-exec" {
    command = "echo ${aws_instance.example.public_ip} > ip_address.txt"
}
# runs on machine but ONLY when resource is created

Recommend using normal shutdown scripts where possible for destroy.

Variables

Terraform loads all files ending in .tf in a directory. Create a file named terraform.tfvars with the following contents:

access_key = "foo"
secret_key = "bar"

Accessing variables:

variable "access_key" {}
variable "secret_key" {}
variable "region" {
    default = "us-east-1"
}

provider "aws" {
    access_key = "${var.access_key}"
    secret_key = "${var.secret_key}"
    region     = "${var.region}"
}

Other ways to pass variables:

$ terraform plan \
    -var 'access_key=foo' \
    -var 'secret_key=bar'

$ terraform plan \
    -var-file="secret.tfvars" \
    -var-file="production.tfvars"

Output

output "ip" {
    value = "${aws_eip.ip.public_ip}"
}

$ terraform output ip

Console

terraform console
> azurerm_resource_group.jb-test.location
> basename(path.cwd)

Import

terraform import {terraform-provider}.{terraform-name} {real-name}

E.g.:

terraform import aws_s3_bucket.{terraform-name} {aws-name}
terraform import azurerm_resource_group.jb-test /subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/jb-test

Debugging

export TF_LOG=TRACE

Manipulating State

terraform state list
terraform state mv aws_route53_record.old_name aws_route53_record.new_name