sample Packer file with variable file for oracle-oci builder

custom-image.json

{
  "variables": {
  "tenancy_ocid": "null",
	"compartment_ocid": "null",
  "user_ocid": "null",
 	"fingerprint": "null",
	"key_file": "null",
	"region": "null",
	"base_image_ocid": "null",
	"image_name": "null",
	"availability_domain": "null",
	"shape": "null",
	"ssh_username": "null",
	"subnet_ocid": "null"
  },
  "builders": [
    {
	  "user_ocid":"{{user `user_ocid`}}",
      "tenancy_ocid": "{{user `tenancy_ocid`}}",
      "fingerprint":"{{user `fingerprint`}}",
      "key_file":"{{user `key_file`}}",
      "availability_domain": "{{user `availability_domain`}}",
      "region": "{{user `region`}}",
      "base_image_ocid": "{{user `base_image_ocid`}}",
      "compartment_ocid": "{{user `compartment_ocid`}}",
      "image_name": "{{user `image_name`}}",
      "shape": "{{user `shape`}}",
      "ssh_username": "{{user `ssh_username`}}",
      "subnet_ocid": "{{user `subnet_ocid`}}",
      "type": "oracle-oci"
    }
  ],
  "provisioners": [
    {
      "type": "shell",
      "scripts": [
        "./install-bind.sh"
      ]
    }
  ]
}

variables.json

{
  "tenancy_ocid": ""
	"compartment_ocid": ""
  "user_ocid": "",
 	"fingerprint": "",
	"key_file": "",
	"region": "",
	"base_image_ocid": "",
	"image_name": "",
	"availability_domain": "",
	"shape": "",
	"ssh_username": "",
	"subnet_ocid": ""
}