How to fix Error: Unknown variable - There is no variable named var in Terraform

Look at the error message to find which variable is missing. The error will state 'There is no variable named X'. For example: 'There is no variable named acr_ip_allowlist'.

In a .tf file (typically variables.tf), add a variable declaration matching the name from the error. Use the appropriate type based on how you intend to use it:

variable "acr_ip_allowlist" {
  type        = list(string)
  description = "List of IP addresses to allow access to ACR"
}

Verify that the variable name in your variable block matches exactly how you reference it in var.name. Terraform is case-sensitive. If declared as variable "my_var", reference it as var.my_var (not var.my_variable or var.myvar).

Choose the correct type for your variable based on how it's used:

# Simple string
variable "region" {
  type = string
}

# List of strings (common for for_each loops)
variable "ip_rules" {
  type = list(string)
}

# Map/object (common for dynamic blocks)
variable "config" {
  type = map(any)
}

After adding the variable declaration, run terraform validate to confirm the syntax is correct and the variable is now recognized:

terraform validate

If validation passes, the variable reference error is resolved.

Terraform needs a value for each variable. You can provide values in multiple ways:

1. Command line: terraform apply -var='acr_ip_allowlist=["192.168.1.1"]'
2. Environment variable: export TF_VAR_acr_ip_allowlist='["192.168.1.1"]'
3. terraform.tfvars file:

acr_ip_allowlist = ["192.168.1.1", "10.0.0.0/8"]

4. Interactive prompt: Terraform will ask for the value if not provided elsewhere