Define S3 Bucket Configuration as an Object Variable

S3 Bucket Configuration Object

Instead of scattering S3 settings across multiple variables, group them into a single object variable. This makes the module interface cleaner and keeps related settings together.

Variable Definition

variable "s3_config" {
  type = object({
    bucket_name       = string
    versioning        = bool
    encryption        = bool
    lifecycle_days    = number
    access_logging    = bool
    force_destroy     = bool
  })
  description = "S3 bucket configuration settings"
  default = {
    bucket_name       = "my-app-data"
    versioning        = true
    encryption        = true
    lifecycle_days    = 90
    access_logging    = false
    force_destroy     = false
  }
}

Using in Resources

resource "aws_s3_bucket" "main" {
  bucket        = "${var.project_name}-${var.environment}-${var.s3_config.bucket_name}"
  force_destroy = var.s3_config.force_destroy
}

resource "aws_s3_bucket_versioning" "main" {
  bucket = aws_s3_bucket.main.id
  versioning_configuration {
    status = var.s3_config.versioning ? "Enabled" : "Disabled"
  }
}

resource "aws_s3_bucket_server_side_encryption_configuration" "main" {
  count  = var.s3_config.encryption ? 1 : 0
  bucket = aws_s3_bucket.main.id

  rule {
    apply_server_side_encryption_by_default {
      sse_algorithm = "AES256"
    }
  }
}

Environment-Specific Overrides

# dev.tfvars
s3_config = {
  bucket_name    = "dev-data"
  versioning     = false
  encryption     = true
  lifecycle_days = 30
  access_logging = false
  force_destroy  = true
}

# prod.tfvars
s3_config = {
  bucket_name    = "prod-data"
  versioning     = true
  encryption     = true
  lifecycle_days = 365
  access_logging = true
  force_destroy  = false
}

Object vs. Separate Variables

Approach	Pros	Cons
Single object	Grouped, clean interface	All-or-nothing defaults
Separate vars	Fine-grained defaults	More variables to manage

The object approach works best when settings are logically cohesive and typically configured together.