Dynamic Credentials with the Azure Provider

You can use Terraform Cloud’s native OpenID Connect integration with Azure to get dynamic credentials for the AzureRM or AzureAD providers in your Terraform Cloud runs. Configuring the integration requires the following steps:

1. Configure Azure: Set up a trust configuration between Azure and Terraform Cloud. Then, you must create Azure roles and policies for your Terraform Cloud workspaces.
2. Configure Terraform Cloud: Add environment variables to the Terraform Cloud workspaces where you want to use Dynamic Credentials.

Once you complete the setup, Terraform Cloud automatically authenticates to Azure during each run. The Azure provider authentication is valid for the length of the plan or apply.

Configure Azure

You must enable and configure an application and service principal with accompanying federated credentials and permissions on Azure. These instructions use the Azure portal, but you can also use Terraform to configure Azure. Refer to our example Terraform configuration.

Create an Application and Service Principal

Follow the steps mentioned in the AzureRM provider docs here: Creating the Application and Service Principal.

As mentioned in the documentation it will be important to make note of the client_id for the application as you will use this later for authentication.

Grant the Application Access to Manage Resources in Your Azure Subscription

You must now give the created Application permission to modify resources within your Subscription.

Follow the steps mentioned in the AzureRM provider docs here: Granting the Application access to manage resources in your Azure Subscription.

Configure Azure Active Directory Application to Trust a Generic Issuer

Finally, you must create federated identity credentials which validate the contents of the token sent to Azure from Terraform Cloud.

Follow the steps mentioned in the AzureRM provider docs here: Configure Azure Active Directory Application to Trust a Generic Issuer.

The following information should be specified:

• Federated credential scenario: Must be set to Other issuer.
• Issuer: The address of Terraform Cloud (e.g., https://app.terraform.io).
  • Important: make sure this value starts with https:// and does not have a trailing slash.
• Subject identifier: The subject identifier from Terraform Cloud that this credential will match. This will be in the form organization:my-org-name:project:my-project-name:workspace:my-workspace-name:run_phase:plan where the run_phase can be one of plan or apply.
• Name: A name for the federated credential, such as tfc-plan-credential. Note that this cannot be changed later.

The following is optional, but may be desired:

• Audience: Enter the audience value that will be set when requesting the identity token. This will be api://AzureADTokenExchange by default. This should be set to the value of TFC_AZURE_WORKLOAD_IDENTITY_AUDIENCE if this has been configured.

Configure Terraform Cloud

You’ll need to set some environment variables in your Terraform Cloud workspace in order to configure Terraform Cloud to authenticate with Azure using dynamic credentials. You can set these as workspace variables.

Required Environment Variables

Optional Environment Variables

You may need to set these variables, depending on your use case.

Configure the AzureRM or AzureAD Provider

Make sure that you’re passing values for the subscription_id and tenant_id arguments into the provider configuration block or setting the ARM_SUBSCRIPTION_ID and ARM_TENANT_ID variables in your workspace.

Make sure that you’re not setting values for client_id, use_oidc, or oidc_token in the provider or setting any of ARM_CLIENT_ID, ARM_USE_OIDC, ARM_OIDC_TOKEN.

Specifying Multiple Configurations

You can add additional configurations to handle multiple distinct Azure setups, enabling you to use multiple provider aliases within the same workspace.

For more details, see Specifying Multiple Configurations.

Required Terraform Variable

To use additional configurations, add the following code to your Terraform configuration. This lets Terraform Cloud supply variable values that you can then use to map authentication and configuration details to the correct provider blocks.

variable "tfc_azure_dynamic_credentials" {
  description = "Object containing Azure dynamic credentials configuration"
  type = object({
    default = object({
      client_id_file_path = string
      oidc_token_file_path = string
    })
    aliases = map(object({
      client_id_file_path = string
      oidc_token_file_path = string
    }))
  })
}

Example Usage

provider "azurerm" {
  features {}
  // Set this to true as we are using OIDC
  use_oidc = true
  client_id_file_path = var.tfc_azure_dynamic_credentials.default.client_id_file_path
  oidc_token_file_path = var.tfc_azure_dynamic_credentials.default.oidc_token_file_path
}

provider "azurerm" {
  features {}
  // Set this to true as we are using OIDC
  use_oidc = true
  alias = "ALIAS1"
  client_id_file_path = var.tfc_azure_dynamic_credentials.aliases["ALIAS1"].client_id_file_path
  oidc_token_file_path = var.tfc_azure_dynamic_credentials.aliases["ALIAS1"].oidc_token_file_path
}