Can we write logics in Terraform Code (IaC) anything like using count.index[ ]?

Question

While, I was working with Terraform I had a question; I will be able to destroy some specific resources using terraform destroy --target [] --target [] or terraform state -rm ; this is okay if we have 50 servers but what if I have 1000 servers and would like to terminate such as odd number instances or even number instances using the array numbers in the list or could we write a script to gather all the corrupted instances and execute that script to terminate all those instances and make that script reusable!!

Is there any way for this, I have searched all over the internet but couldn't find any solution; may be this question is dumb but I was just curious!!!!

Is there any documentation that explains this is would not be possible through terraform!!!!

Have you looked at index function here terraform.io/docs/configuration/functions/index.html ? — harshavmb
– harshavmb, Commented Nov 26, 2020 at 19:32

cloudartisan · Accepted Answer · 2020-11-30 12:02:58Z

0

You could expose the count as an output:

output "server_count" {
  value = var.server_count
}

and write a script (shell/Python/etc) that takes that count as an argument and uses it to taint every odd resource:

#!/bin/bash
# usage: taint_odd_servers.sh <num servers>

SERVER_COUNT=$1

i=0
while [ $i -lt $SERVER_COUNT ]
do
  REMAINDER=$(( $i % 2 ))
  if [ $REMAINDER -ne 0 ]
  then
    terraform taint "your_server_resource[${i}]"
  fi
  i=$(($i+1))
done

You could then call that script like:

taint_odd_servers.sh $(terraform output server_count)

answered Nov 30, 2020 at 12:02

cloudartisan

6564 silver badges6 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

Can we write logics in Terraform Code (IaC) anything like using count.index[ ]?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related