» Azure Provider: Authenticating using the Azure CLI

Terraform supports a number of different methods for authenticating to Azure:

Authenticating to Azure using the Azure CLI (which is covered in this guide)
Authenticating to Azure using Managed Service Identity
Authenticating to Azure using a Service Principal and a Client Certificate
Authenticating to Azure using a Service Principal and a Client Secret

We recommend using either a Service Principal or Managed Service Identity when running Terraform non-interactively (such as when running Terraform in a CI server) - and authenticating using the Azure CLI when running Terraform locally.

» Important Notes about Authenticating using the Azure CLI

Prior to version 1.20 the AzureRM Provider used a different method of authorizing via the Azure CLI where credentials reset after an hour - as such we'd recommend upgrading to version 1.20 or later of the AzureRM Provider.
Terraform only supports authenticating using the az CLI (and this must be available on your PATH) - authenticating using the older azure CLI or PowerShell Cmdlets is not supported.
Authenticating via the Azure CLI is only supported when using a User Account. If you're using a Service Principal (for example via az login --service-principal) you should instead authenticate via the Service Principal directly (either using a Client Secret or a Client Certificate).

» Logging into the Azure CLI

Note: If you're using the China, German or Government Azure Clouds - you'll need to first configure the Azure CLI to work with that Cloud. You can do this by running:

$ az cloud set --name AzureChinaCloud|AzureGermanCloud|AzureUSGovernment

Firstly, login to the Azure CLI using:

$ az login

Once logged in - it's possible to list the Subscriptions associated with the account via:

$ az account list

The output (similar to below) will display one or more Subscriptions - with the id field being the subscription_id field referenced above.

[
  {
    "cloudName": "AzureCloud",
    "id": "00000000-0000-0000-0000-000000000000",
    "isDefault": true,
    "name": "PAYG Subscription",
    "state": "Enabled",
    "tenantId": "00000000-0000-0000-0000-000000000000",
    "user": {
      "name": "user@example.com",
      "type": "user"
    }
  }
]

Should you have more than one Subscription, you can specify the Subscription to use via the following command:

$ az account set --subscription="SUBSCRIPTION_ID"

» Configuring Azure CLI authentication in Terraform

Now that we're logged into the Azure CLI - we can configure Terraform to use these credentials.

To configure Terraform to use the Default Subscription defined in the Azure CLI - we can use the following Provider block:

provider "azurerm" {
  # Whilst version is optional, we /strongly recommend/ using it to pin the version of the Provider being used
  version = "=1.24.0"
}

More information on the fields supported in the Provider block can be found here.

At this point running either terraform plan or terraform apply should allow Terraform to run using the Azure CLI to authenticate.

It's also possible to configure Terraform to use a specific Subscription - for example:

provider "azurerm" {
  # Whilst version is optional, we /strongly recommend/ using it to pin the version of the Provider being used
  version = "=1.24.0"

  subscription_id = "00000000-0000-0000-0000-000000000000"
}

More information on the fields supported in the Provider block can be found here.

At this point running either terraform plan or terraform apply should allow Terraform to run using the Azure CLI to authenticate.

If you're looking to use Terraform across Tenants - it's possible to do this by configuring the Tenant ID field in the Provider block, as shown below:

provider "azurerm" {
  # Whilst version is optional, we /strongly recommend/ using it to pin the version of the Provider being used
  version = "=1.24.0"

  subscription_id = "00000000-0000-0000-0000-000000000000"
  tenant_id       = "11111111-1111-1111-1111-111111111111"
}

More information on the fields supported in the Provider block can be found here.

At this point running either terraform plan or terraform apply should allow Terraform to run using the Azure CLI to authenticate.