Terraform: BucketAlreadyOwnedByYou error on S3 bucket creation

Running terraform apply on a new workspace:

Error: creating S3 Bucket (my-app-artifacts): BucketAlreadyOwnedByYou: 
Your previous request to create the named bucket succeeded and you already own it.

What happened: The S3 bucket already existed in AWS (created manually earlier) but wasn't in the Terraform state. Terraform tried to create it fresh and hit the conflict.

Option 1: Import the existing bucket into state

This is the right approach if you want Terraform to manage the existing bucket:

terraform import aws_s3_bucket.artifacts my-app-artifacts

After import, terraform plan should show no changes (or only differences between real config and your Terraform code).

Option 2: Delete the manual bucket and let Terraform create it

Only if the bucket is empty and you don't need its contents:

aws s3 rb s3://my-app-artifacts --force
terraform apply

Option 3: Use data source instead of resource

If you don't want Terraform managing the bucket (just referencing it):

# Instead of:
resource "aws_s3_bucket" "artifacts" {
  bucket = "my-app-artifacts"
}
 
# Use:
data "aws_s3_bucket" "artifacts" {
  bucket = "my-app-artifacts"
}

Data sources read existing resources without creating/managing them.

Lesson: Before creating resources with Terraform, check if they already exist in AWS. Use terraform import to bring existing AWS resources under Terraform management rather than recreating them.