Is there any to check not used variable in terraform?

Yes, in Terraform, you can check for unused variables using the following methods:

1. Using terraform validate

Terraform has a built-in validation command that can sometimes catch unused variables.

terraform validate

However, this may not always detect unused variables.

2. Using tflint (Recommended)

TFLint is a linter for Terraform that can detect unused variables.

Install TFLint:

brew install tflint  # macOS
choco install tflint # Windows

Run TFLint:

tflint --enable-rule=terraform_unused_declarations

This will list all unused variables in your Terraform configuration.

3. Using terraform console

If you want to manually inspect the variables, you can run:

terraform console

Then check if a variable exists in var:

var.variable_name

If the variable does not exist, it may be unused.

4. Using grep or rg (Ripgrep)

If you suspect unused variables in a file, you can manually check by searching for their usage.

Grep:

grep -r "variable" .

Ripgrep (Faster):

rg "variable" .

Then cross-check the variables defined in variables.tf but never referenced in main.tf or modules/.

5. Using terraform graph (Advanced)

Run:

terraform graph | grep var.

This will show all referenced variables. If a variable is not appearing, it might be unused.

Best Practice

Always review your variables.tf and remove any variables that are no longer needed. Automate this check using TFLint in CI/CD pipelines.

Would you like a script to automate checking for unused variables?