%YAML 1.2
---
version: 1.1

build:
  hcl_type: block

  name: learn-packer
  
  sources:
    - source.docker.ubuntu
    - source.docker.ubuntu-focal

  provisioner:
    hcl_type: block

    shell_1:
      hcl_type: label
      hcl_name: shell

      environment_vars:
        - FOO=hello world

      inline:
        - echo Adding file to Docker Container
        - "echo \"FOO is $FOO\" > example.txt"

    shell_2:
      hcl_type: label
      hcl_name: shell

      inline:
        - echo Running ${var.docker_image} Docker image.
...