How to store Terraform provisioner "local-exec" output in local variable and use variable value in "remote-exec" - variables

Question

I am working with Terraform provisionar. and in one scenario I need to execute a 'local-exec' provisionar and use the output [This is array of IP addesses] of the command into next 'remote-exec' provisionar.
And i am not able to store the 'local-exec' provisionar output in local variable to use later. I can store it in local file but not in intermediate variable
count = "${length(data.local_file.instance_ips.content)}"
this is not working.
resource "null_resource" "get-instance-ip-41" {
provisioner "local-exec" {
command = "${path.module}\\scripts\\findprivateip.bat > ${data.template_file.PrivateIpAddress.rendered}"
}
}
data "template_file" "PrivateIpAddress" {
template = "/output.log"
}
data "local_file" "instance_ips" {
filename = "${data.template_file.PrivateIpAddress.rendered}"
depends_on = ["null_resource.get-instance-ip-41"]
}
output "IP-address" {
value = "${data.local_file.instance_ips.content}"
}
# ---------------------------------------------------------------------------------------------------------------------
# Update the instnaces by installing newrelic agent using remote-exec
# ---------------------------------------------------------------------------------------------------------------------
resource "null_resource" "copy_file_newrelic_v_29" {
depends_on = ["null_resource.get-instance-ip-41"]
count = "${length(data.local_file.instance_ips.content)}"
triggers = {
cluster_instance_id = "${element(values(data.local_file.instance_ips.content[count.index]), 0)}"
}
provisioner "remote-exec" {
connection {
agent = "true"
bastion_host = "${aws_instance.bastion.*.public_ip}"
bastion_user = "ec2-user"
bastion_port = "22"
bastion_private_key = "${file("C:/keys/nvirginia-key-pair-ajoy.pem")}"
user = "ec2-user"
private_key = "${file("C:/keys/nvirginia-key-pair-ajoy.pem")}"
host = "${self.triggers.cluster_instance_id}"
}
inline = [
"echo 'license_key: 34adab374af99b1eaa148eb2a2fc2791faf70661' | sudo tee -a /etc/newrelic-infra.yml",
"sudo curl -o /etc/yum.repos.d/newrelic-infra.repo https://download.newrelic.com/infrastructure_agent/linux/yum/el/6/x86_64/newrelic-infra.repo",
"sudo yum -q makecache -y --disablerepo='*' --enablerepo='newrelic-infra'",
"sudo yum install newrelic-infra -y"
]
}
}

Answer 1

Unfortunately you can't. The solution I have found is to instead use an external data source block. You can run a command from there and retrieve the output(s), the only catch is that the command needs to produce json to standard output (stdout). See documentation here. I hope this is some help to others trying to solve this problem.