String interpolation

"${expression}"

"${var.registry}/${var.image}:${var.tag}"

variable "version" {
  type = string
}

variable "app" {
  type    = string
  default = "api"
}

task "build" {
  commands = [
    "go build -ldflags \"-X main.version=${var.version}\" -o bin/${var.app} ./cmd/${var.app}",
  ]
}

computed "image" {
  expression = "${env("CI_REGISTRY", "registry.example.com")}/${var.app}:${var.version}"
}

variable "branch" {
  type = string
}

task "build" {
  commands = ["docker build -t myapp:${replace(lower(var.branch), "/", "-")} ."]
}

commands = ["echo $${HOME}"]

variable "debug" {
  type    = bool
  default = false
}

task "run" {
  commands = ["./bin/app ${var.debug ? "--debug" : ""}"]
}