build {
  name    = "learn-packer"
  sources = [
    "source.docker.ubuntu",
    "source.docker.ubuntu-focal",
  ]
  
  provisioner "shell" {
    environment_vars = [
      "FOO=hello world",
    ]
    inline           = [
      "echo Adding file to Docker Container",
      "echo \"FOO is $FOO\" > example.txt",
    ]
  }
  

  provisioner "shell" {
    inline = [
      "echo Running ${var.docker_image} Docker image.",
    ]
  }
}