range_example.pp

class buildkite::install(
  Pattern[/(\d+\.\d+\.\d+|installed)/] $agent_version = $buildkite::agent_version,
  $agent_count = 1
) {

  # more puppet code

  if $agent_count > 1 {
    range('2', String($agent_count)).each |$extra_agent| {
      file { "/usr/lib/systemd/system/buildkite-agent${extra_agent}.service":
        source => "puppet:///modules/${module_name}/buildkite-agent-service.template",
        mode   => '0644',
      }
    }
  }

  # puppet code
}