Reuse versioned modules

How to do it

A module is a folder of resources with named inputs and outputs. Check inputs with validation blocks. Publish shared modules with version tags, and refer to them as ?ref=v1.4.0 or with a registry version. Upgrade one environment at a time.

Example

module "web" {
  source        = "git::https://git.example.com/infra/modules.git//web?ref=v1.4.0"
  environment   = "production"
  instance_size = "m7g.large"
}

variable "environment" {
  type = string
  validation {
    condition     = contains(["staging", "production"], var.environment)
    error_message = "environment must be staging or production."
  }
}

# Fails when a remote module is used without a version tag
! grep -rnE 'source *= *"git::' infra --include=*.tf | grep -v '?ref=v[0-9]'

How to check

Every git source line holds ?ref= with a version tag, as the grep below confirms. Every registry module block has a version argument.