Removing Backend pools and load balancer rules before creating another - azure

Question

I have terraform script which creates Backend address pools and Loadbalancer rules in Loadbalancer in resource group. These tasks are included in Azure-pipeline. FOr the first time I run the pipeline.Its creating properly. If I run the pipeline for the second time. Its not updating the existing one .Its keeping the Backend address pools and Loadbalancer rules which are created by previous release and adding the extra Backend address pools and Loadbalancer rules for this release which is causing duplicates in Backend address pools and Loadbalancer rules. Any suggestions on this please
resource "azurerm_lb_backend_address_pool" "example" {
resource_group_name = azurerm_resource_group.example.name
loadbalancer_id = azurerm_lb.example.id
name = "BackEndAddressPool"
}
resource "azurerm_lb_rule" "example" {
resource_group_name = azurerm_resource_group.example.name
loadbalancer_id = azurerm_lb.example.id
name = "LBRule"
protocol = "All"
frontend_port = 0
backend_port = 0
frontend_ip_configuration_name = "PublicIPAddress"
enable_floating_ip = true
backend_address_pool_id = azurerm_lb_backend_address_pool.example
}

Answer 1

This is likely happening because the Terraform state file is being lost between pipeline runs.
By default, Terraform stores state locally in a file named terraform.tfstate. When working with Terraform in a team, use of a local file makes Terraform usage complicated because each user must make sure they always have the latest state data before running Terraform and make sure that nobody else runs Terraform at the same time.
With remote state, Terraform writes the state data to a remote data store, which can then be shared between all members of a team. Terraform supports storing state in Terraform Cloud, HashiCorp Consul, Amazon S3, Alibaba Cloud OSS, and more.
Remote state is a feature of backends. Configuring and using remote backends is easy and you can get started with remote state quickly. If you then want to migrate back to using local state, backends make that easy as well.
You will want to configure Remote State storage to keep the state. Here is an example using Azure Blob Storage:
terraform {
backend "azurerm" {
resource_group_name = "StorageAccount-ResourceGroup"
storage_account_name = "abcd1234"
container_name = "tfstate"
key = "prod.terraform.tfstate"
}
}
Stores the state as a Blob with the given Key within the Blob Container within the Blob Storage Account. This backend also supports state locking and consistency checking via native capabilities of Azure Blob Storage.
This is more completely described in the azurerm Terraform backend docs.
Microsoft also provides a Tutorial: Store Terraform state in Azure Storage, which goes through the setup step by step.