This error occurs when attempting to create an Azure Container Registry (ACR) that already exists in Azure. The registry name must be globally unique across all Azure subscriptions. This typically happens when the resource was previously created outside Terraform or when Terraform state is lost. The fix involves checking if the resource exists, importing it into state, using unique names, or properly managing Terraform backend state.
Azure Container Registry names must be globally unique across all of Azure. When Terraform attempts to create a registry with a name that already exists (either in your subscription or any other), Azure returns the AlreadyExists error. This typically indicates either: (1) the resource was created previously but Terraform state was lost, (2) the resource exists in another subscription or tenant, (3) Terraform state management is misconfigured in CI/CD pipelines, or (4) the chosen name is already taken by another user.
Run the Azure CLI command to verify if the ACR with the desired name exists:
az acr show --resource-group <resource-group-name> --name <registry-name>If the resource exists and you want to manage it with Terraform, proceed to import it into state. If it doesn't exist, the issue is likely a Terraform state problem.
If the ACR already exists in Azure, import it into your Terraform state using the import command:
terraform import azurerm_container_registry.acr /subscriptions/<subscription-id>/resourceGroups/<resource-group-name>/providers/Microsoft.ContainerRegistry/registries/<registry-name>Replace the placeholders with your actual values. You can get the subscription ID with az account show --query id. After importing, Terraform will track the existing resource and won't try to recreate it.
To avoid name conflicts entirely, use a random suffix in your registry name:
resource "random_string" "acr_suffix" {
length = 8
special = false
upper = false
}
resource "azurerm_container_registry" "acr" {
name = "myacr${random_string.acr_suffix.result}"
resource_group_name = azurerm_resource_group.rg.name
location = azurerm_resource_group.rg.location
sku = "Basic"
admin_enabled = false
}This ensures a globally unique name by combining your prefix with random characters.
If deploying from CI/CD pipelines, ensure Terraform state is persisted in a remote backend. Add this configuration to your main.tf:
terraform {
backend "azurerm" {
resource_group_name = "terraform-state-rg"
storage_account_name = "tfstatestg"
container_name = "tfstate"
key = "prod.terraform.tfstate"
}
}Initialize the backend with terraform init. This prevents state loss between pipeline runs and ensures all team members work with the same state.
If you want Terraform to fully manage the resource and the ACR contains no critical data, you can delete it and let Terraform recreate it:
# Remove from Azure
az acr delete --resource-group <resource-group-name> --name <registry-name>
# Clear Terraform state if needed
terraform state rm azurerm_container_registry.acr
# Re-run Terraform
terraform applyWARNING: Only do this if the ACR is empty or the data is not needed. This operation is destructive and cannot be undone.
Before running Terraform in CI/CD, verify that:
1. Backend storage account and container exist
2. Pipeline has read/write access to the backend storage
3. terraform init is called before every terraform plan or terraform apply
4. State file isn't manually deleted or modified
Run terraform state list to verify Terraform can see existing resources in state. If empty, state is not properly persisted.
ACR names are globally unique within the entire Azure ecosystem, making them prone to naming conflicts. For multi-environment deployments, consider using deployment slot names or random suffixes. If you're managing ACRs across multiple subscriptions, use Azure Data Source to reference existing registries instead of creating new ones. For enterprise scenarios, implement naming conventions using prefixes (company code + environment + random) and validate names before applying. The AlreadyExists error might appear during provider initialization if other checks fail; ensure your azurerm provider version is current and compatible with your Terraform version. Some organizations use Azure Policy to enforce naming standards and prevent duplicate resource names at the API level.
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