Line continuation within a variable

Terraform
1

Is there a way to store multiple lines of bash commands into a variable? I’ve not found any examples of how to do this anywhere and have failed to come up with it on my own so far.

use case - i’m trying to use a null_resource to call provisioner “local-exec” and then pass in multiple commands. i can do this using <<EOT if i do it directly in the null_resource itself, but if i try to put the commands into a variable, terraform will fail on PLAN or APPLY because it “failed to load root config module, error parsing (path/variables.tf)” with illegal characters usually as the reason.

i’d like to be able to create a couple of different variables with different commands, then do a lookup in the actual null_resource to call the proper variable based on my lookup criteria. i just am struggling to figure out how to pass in multiple lines via a variable. Any help would be appreciated.

2

Hi @kylecompassion!

Could you please share exactly what you tried that led to the error “failed to load root config module, error parsing (path/variables.tf)”? That should help clarify what exactly you are trying to do here.

4

I’ll try to explain the outcome i’m looking for as it may be i’m going the completely wrong direction in the first place. Below is a null_resource with multiple commands in the local-exec piece. I’m trying to get everything within {} of local-exec into a variable so that i can maintain multiple variables with unique commands in each variable, and then use a LOOKUP within the null_resource so i can call different variables based on different ${terraform.workspace} values. So I’m trying to figure out how to properly write the variable so that it works when called by the local-exec provisioner.

  1. if there’s a better way to do this, let me know
  2. if this is a good way to reach my desired outcome, how do i do it?

Thanks!

resource “null_resource” “datadog_metrics” {
depends_on = [“null_resource.platform_auth”]
provisioner “local-exec” {
command = <<EOT
sudo runuser -l user -c ‘kubectl apply -f /home/terraform/kube-state-metrics/’;
sudo runuser -l user -c ‘kubectl apply -f /home/terraform/datadog_cluster_agent’/
EOT
}
}

5

Hi @kylecompassion! Here’s one way to do what you’re trying to do:

locals {
  per_workspace_commands = {
    workspace_a = <<-EOT
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/kube-state-metrics/’
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/datadog_cluster_agent/'
    EOT
    workspace_b = <<-EOT
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/kube-state-metrics/’
    EOT
  }
}

resource "null_resource" "datadog_metrics" {
  depends_on = [null_resource.platform_auth]

  provisioner "local-exec" {
    command = local.per_workspace_commands[terraform.workspace]
  }
}

I used a local value here because it didn’t sound from your description like this is something that should be overridden by a calling module, but if you do need the calling module to customize this then you could use a variable block instead, with the default value set to the same map expression:

variable "per_workspace_commands" {
  type = map(string)
  default = {
    workspace_a = <<-EOT
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/kube-state-metrics/’
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/datadog_cluster_agent/'
    EOT
    workspace_b = <<-EOT
      sudo runuser -l user -c ‘kubectl apply -f /home/terraform/kube-state-metrics/’
    EOT
  }
}
1 Like
6

Hi,
I have almost the same issue with local-exec. Please take a look at below.

resource "null_resource" "kops" {
  provisioner   "local-exec" {
      command    = <<EOT
kops create cluster 
--cloud ${var.cloud_provider} 
--name=${var.region}-${var.environment}-${var.city}.${var.k8s_domain} 
--state=s3://${var.bucket_name} 
--zones=${join(",",var.azs)} 
--node-count ${var.node_count} 
--node-size ${var.node_size} 
--master-count ${var.master_count} 
--master-size ${var.master_size} 
--master-zones ${element(var.azs, 0)},${element(var.azs, 1)},${element(var.azs, 2)} 
--vpc=${var.vpc_id.vpc_id} 
--networking=${var.networking_type} 
--subnets=${var.subnet_ids} 
--out=${var.region}-${var.environment}-${var.city}.${var.k8s_domain} 
--target=${var.target} 
--topology ${var.topology} 
--ssh-public-key ~/.ssh/kubernetes-poc.pub 
--yes
EOT
  }
}

I am getting the error below.

null_resource.cluster_folder: Creating...
null_resource.cluster_folder: Provisioning with 'local-exec'...


Error: 6 problems:

- Invalid function argument: Invalid value for "lists" parameter: list of string required.
- Error in function call: Call to function "element" failed: cannot read elements from string.
- Error in function call: Call to function "element" failed: cannot read elements from string.
- Error in function call: Call to function "element" failed: cannot read elements from string.
- Unsupported attribute: This value does not have any attributes.
- local-exec provisioner command must be a non-empty string

So any idea about the issue or how to guide me to the correct path?

Thank you

7

I found the issue and it’s already fixed.