How to generate external user-data and pass it into the terrform module.

nmg-jenkins-external-userdata.tf

module "jenkins_ha_agents" {
  source = "neiman-marcus/jenkins-ha-agents/aws"

  snipped for brevity…

  extra_agent_userdata        = "${data.template_file.extra_agent_userdata.rendered}"
  extra_agent_userdata_merge  = "list(append)+dict(recurse_array)+str()"
  extra_master_userdata       = "${data.template_file.extra_master_userdata.rendered}"
  extra_master_userdata_merge = "list(append)+dict(recurse_array)+str()"
}

data "template_file" "extra_agent_userdata" {
  vars {
    foo = "bar"
  }

  template = <<EOF
---
runcmd:
- echo 'foo = ${foo}'
EOF
}

data "template_file" "extra_master_userdata" {
  vars {
    foo = "bar"
  }
  
  template = <<EOF
---
runcmd:
- echo 'foo = ${foo}'
EOF
}