Import bash script as UserData in AWS CFN template using Troposphere

[Yogesharuna]

0

I am trying to create an AWS template using Troposphere and I am stuck at a point where I have to use my Bash Script as UserData. My main problem being Ref used in Bash Script. I am importing Bash Script as a file read and encode them to Base64 as:

UserData= Base64(Join("", [open('path to my bashscript', "r").read() .splitlines(True)]))

My bash script has Ref used as:
#!/bin/bash
set -x
export -f check_instance_service_status
timeout Ref('ValueReferenced') bash -c "check_instance_service_status $ELB_NAME"

The output I am getting is:
"#!/bin/bash\n",
"set -x\n",
"\n",
" export -f check_instance_service_status\n",
" timeout Ref('ValueReferenced') bash -c "check_instance_service_status $ELB_NAME"\n",
" RC=$?\n",

However, I want the Ref to be converted to proper JSON compatible as:
" timeout "",
{
"Ref": "ValueReferenced"
},

[urluba]

Hi,

You have to use the Fn::Sub function, before the call to Base64. By example:

    instance_launchconfig = template.add_resource(
        asg.LaunchConfiguration(
            "InstanceLaunchConfiguration",
            ImageId=Ref(parameters["instance_ami"]),
            InstanceType=Ref(parameters["instance_type"]),
            UserData=Base64(
                Sub(
                    # Your script here
                )
            ),
        )
    )