CODEWITHSUNDEEP
terraformterraform-provider-aws
M A.
M A.

Reputation: 949

Does terraform allow us to override variables

Does terraform provide such functionality to override variable values? Let suppose I have declared two variables given below.

variable "foo" {}
variable "bar" { default = "false"}

foo is mandatory and bar assigned with default value false. Is there any resoruce available in terraform in which I can reassign or override the bar value? I'm asking this in resource perspective. I know I could do this using terraform-modules.

I've tried this use null_resource but didn't get an expected results. It still returns the default value.

resource "null_resource" "this" {
  provisioner "local-exec" {
    command = "echo ${var.env} > ${var.newvar}"
  }
}

Also I wanted to run curl in command attribute. Do I need to use an `interpreter. if so then what would be its vaule?

interpreter = ["shell","?"] what sete of values should I pass to execute curl command in local-exec provisioner.

bash script

function check_efs() {
curl -ls https://elasticfilesystem.us-east-1.amazonsaws.com
if [ $? -eq 0 ]; then
        output=1
else:
        output=0
}

function produce_output() {
value=$(output)

jq -n \
    --arg is_efs_exist "$value" \
    '{"is_efs_exist":$is_efs_exist}'
}

check_efs
produce_output

Upvotes: 5

Views: 18145

Answers (1)

KJH
KJH

Reputation: 2430

[Answering the 1st question about overrides...]

There are a few ways you could tackle this. I don't know your exact use case, so your mileage may vary.

  1. You could export an environment variable that has the value you'd like to use. For example, you could set the bar var to a new value with export TF_VAR_bar=newvalue and then run terraform in that session. Or combine them on the same line: TF_VAR_bar=newvalue terraform apply

    Ref: https://www.terraform.io/docs/configuration/environment-variables.html

  2. Use an override file. E.g.: override.tf could contain variable "bar" { default = "newvalue"} or any other TF code. It's loaded last.

    Ref: https://www.terraform.io/docs/configuration/override.html

  3. Put your code into a TF module, then you could call the module and pass along the value of bar that you'd like. This is particularly useful if you keep re-using the same code and wanting to provision different instances of some set of resources with varying parameters.

    Ref: https://www.terraform.io/docs/configuration/modules.html

HTH!

Upvotes: 5

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