Deploy Azure Resources via Terraform and Azure Pipeline

Azure DevOps and Azure Pipeline are powerful tools for automating the deployment of infrastructure as code. By combining these tools with Terraform, we can deploy Azure resources quickly and efficiently. In this article, we will walk through the steps required to set up Azure DevOps and Azure Pipeline to deploy Azure resources via Terraform.

The first step is to create a service connection in the Azure DevOps project. This connection will allow the pipeline to communicate with Azure and deploy resources.

Create Service Connection

To create a service connection, follow these steps:

1. Navigate to Project Settings → Service connections
2. Click on New service connection
3. Choose Azure Resource Manager
4. Follow the prompts to create the connection

Once the connection is created, we can move on to creating a variable group. This group will store key-value pairs that can be referenced in the pipeline’s YAML file.

Create Variable Group

To create a variable group, follow these steps:

1. Navigate to Pipelines → Library → Variable group
2. Click on New variable group
3. Give the group a name (e.g., dev) and add key-value pairs
4. Reference the variable group in the pipeline’s YAML file using group: dev and $(SUBSCRIPTION_ID)

Finally, we need to add the Terraform tasks to the YAML file. This will allow the pipeline to run Terraform commands and deploy resources.

Add Terraform Tasks

To add Terraform tasks, follow these steps:

1. Install the Terraform extension in Azure DevOps
2. Add Terraform tasks to the pipeline’s YAML file

Here’s an example of what the YAML file might look like:

variables:
  - group: dev
  - name: armServiceConnection
    value: 'ARM_SERVICE_CONNECTION'
- task: AzureCLI@2
        displayName: 'Deploy Web App'
        inputs:
          azureSubscription: ${{ variables.armServiceConnection }}
          scriptType: bash
          scriptLocation: inlineScript
          addSpnToEnvironment: true
          inlineScript: |
            make deploy \
              ARM_CLIENT_ID=$servicePrincipalId \
              ARM_CLIENT_SECRET=$servicePrincipalKey \
              ARM_SUBSCRIPTION_ID=$(SUBSCRIPTION_ID) \
              ARM_TENANT_ID=$tenantId \
              TF_VAR_identifier='$(Build.sourceBranchName)'            

In this example, the AzureCLI task is used to log in to Azure and set the subscription. The env section contains environment variables that Terraform will use to deploy resources.

azureSubscription refers to the service connection name that was created earlier.

ARM_SUBSCRIPTION_ID is the subscription ID that is stored in the service connection.

ARM_CLIENT_ID, ARM_CLIENT_SECRET, and ARM_TENANT_ID are other required parameters that are automatically populated once the service connection is created.

addSpnToEnvironment needs to be set to true to allow using the service principle for login instead of personal credentials. By default, it is set to false.

Other Terraform environment variables can be set using the TF_VAR_ prefix.