{   
    "variables":
        {
            "accesskey": "",
            "secretkey": "",
            "shellpath": "packages.sh"
        },
    "builders":[
        {
            "type": "amazon-ebs",
            "access_key": "{{user `accesskey`}}",
            "secret_key": "{{user `secretkey`}}",
            "region": "ap-south-1",
            "source_ami": "ami-sa7608343426b",
            "instance_type": "t2.micro",
            "ssh_username": "ubuntu",
            "ami_name": "nginx",
            "tags": {
              "OS_Version": "Ubuntu",
              "Release": "Latest"
            }
        }   
    ],
   "provisioners":[
       {
       "type": "shell",
       "script": "{{user `shellpath`}}"
       }  
    ]

}