Terraform Target

October 18, 2023

Targetting resources in terraform is selecting and applying changes to specific resources within your Terraform configuration. This feature is used to control which resources are created, modified, or destroyed

Prerequisites:

Install Terraform - here

Targeting Syntax

terraform <command> -target=<resource-type>.<resource-name>

Example of terrafom apply command targeting aws_instance.example resource

terraform apply -target=aws_instance.example

Example usage:

Example terraform code:

resource "aws_s3_bucket" "a" {
  bucket = "example-bucket-1a"
}

resource "aws_s3_bucket" "b" {
  bucket = "example-bucket-2b"
}

While running terraform apply we would create both buckets:

Terraform will perform the following actions:

  # aws_s3_bucket.a will be created
  + resource "aws_s3_bucket" "a" {
      + acceleration_status         = (known after apply)
      + acl                         = (known after apply)
      .....
Plan: 2 to add, 0 to change, 0 to destroy.

Do you want to perform these actions?

After apply finished, let's destroy "aws_s3_bucket" "b", while keeping "aws_s3_bucket" "a". Run:

terraform destroy --target aws_s3_bucket.b

After destroy finished we can see that bucket 1a is still running:

$aws s3 ls
2023-10-20 12:23:09 example-bucket-1a

Now lets add another bucket to the code:

resource "aws_s3_bucket" "a" {
  bucket = "example-bucket-1a"
}

resource "aws_s3_bucket" "b" {
  bucket = "example-bucket-2b"
}

resource "aws_s3_bucket" "c" {
  bucket = "example-bucket-3c"
}

We would target resource aws_s3_bucket.c:

terraform apply --target aws_s3_bucket.c

As expected, we can see now 2 buckets running:

aws s3 ls
2023-10-20 12:23:09 example-bucket-1a
2023-10-20 12:30:53 example-bucket-3c

There is a CLI Tool which makes it easier to target terraform resources. You can find more about it here