Packer AWS ami filters / use variable in name

Packer
1

Hi,

I’m giving a first try to switch to HCL for my packer configuration.
This is mostly lead by the need to have some conditional, and readability, and common languages with our terraform stacks, and… so on :smiley:

I’d like to have the following, which would let me easily switch between the creation of an amd64 / arm64 ami creation, without having to maintain multiple repos.

data "amazon-ami" "ami" {
  filters = {
    name                = local.source_ami
    root-device-type    = "ebs"
    virtualization-type = "hvm"
  }
  most_recent = true
  owners      = ["amazon"]
  region      = var.region
}

where my vars in variables.pkr.hcl are

variable "platform" {
  description = "Target platform to build on. Must be in (linux-amd64, linux-arm64). Defaults to linux-amd64."
  type    = string
  default = "linux-amd64"
  validation {
    condition     = contains(["linux-amd64", "linux-arm64"], var.platform)
    error_message = "We currently only support linux-amd64 and linux-arm64."
  }
}

locals {
  source_ami = var.platform == "linux-amd64" ? "amzn2-ami-hvm-*-x64_64-gp2" : "amzn2-ami-hvm-*-arm64-gp2"
}

But this fail with the following

Error: Unsupported attribute

  on main.pkr.hcl line 7:
  (source code not available)

This object does not have an attribute named "source_ami".

Am I missing something or is the interpolation not permitted in ami name filter ?
I tried both interpolation and use of a full variable (like above), no success.
I can use it everywhere else, but not here.

Sidenote : I was on packer 1.7.0 and tried to update to 1.7.4 but I get the same error.
Sidenote2 : If I skip the variable and put the string to the filter value, it works perfectly.

2

After some digging, I think I may answer to myself.
In the packer-plugin-amazon, I see no interpolation on datasource.ami.config when there is some in ebs.builder for example.

I’m not really fluentd in go, but I think my assertion is correct.
If any maintainer could confirm :slight_smile:

3

I believe you are correct.