example.json

{
  "variables": {
    "aws_access_key": "",
    "aws_secret_key": ""
  },
  "builders": [
    {
      "type": "amazon-ebs",
      "access_key": "{{user `aws_access_key`}}",
      "secret_key": "{{user `aws_secret_key`}}",
      "region": "us-east-1",
      "source_ami_filter": {
        "filters": {
          "virtualization-type": "hvm",
          "name": "ubuntu/images/*ubuntu-xenial-16.04-amd64-server-*",
          "root-device-type": "ebs"
        },
        "owners": ["099720109477"],
        "most_recent": true
      },
      "instance_type": "t2.micro",
      "ssh_username": "ubuntu",
      "ami_name": "packer-example {{timestamp}}"
    }
  ],
  "provisioners": [
    {
      "type": "shell",
      "inline": [
        "sleep 80"
      ]
    },
    {
      "type": "ansible",
      "user": "root",
      "playbook_file": "files/playbook_master.json",
      "extra_arguments": [ "-vvvv", "--extra-vars", "--become-method=su"],
      "ansible_env_vars": ["ANSIBLE_FORCE_COLOR=true", "USE_PERSISTENT_CONNECTIONS=false"]
    }, {
      "type": "shell",
      "inline": [
        "echo Thanks to https://alex.dzyoba.com/blog/packer-for-docker/ and make sure to use jsonnet to properly share the configuration."
      ]
    }
  ]
}

playbook_template.jsonnet

{
    become: true,
    become_method: 'su',
    hosts: 'all',
    vars: {
      kubernetes_allow_pods_on_master: true,
      kubernetes_role: type,
    },
    {
      name: "slow",
      command: "/bin/sleep 90",
      register: "some_job"
    }
    ,
    {
      name: "check_who",
      command: "whoami", # issue exists also when I use `shell: "whoami",`
      become_user: "root",
      # become_method: "su",
      become: true,
      # ansible_become: true,
    }
  ]
}