⚖️ Azure Bicep vs Terraform: Which One Should You Use?

Introduction

Infrastructure as Code (IaC) is a critical part of modern cloud development, allowing teams to define and manage infrastructure in a declarative and repeatable way. Two of the most popular IaC tools for Microsoft Azure are Azure Bicep and Terraform.

But which one should you use? This article compares Bicep and Terraform based on syntax, features, ease of use, ecosystem support, and real-world scenarios.

What is Azure Bicep?

Azure Bicep is a domain-specific language (DSL) developed by Microsoft as an abstraction over ARM (Azure Resource Manager) templates. It simplifies Azure infrastructure deployment by providing a cleaner syntax compared to JSON-based ARM templates.

Key Features of Azure Bicep

✔ Declarative syntax: Simplifies Azure infrastructure provisioning.
✔ Native Azure support: Built and maintained by Microsoft.
✔ No state management required: Uses Azure’s existing infrastructure model.
✔ Deep integration with Azure services: Works seamlessly with Microsoft tools like Azure DevOps.
✔ Easier debugging compared to ARM templates: More human-readable and less verbose.

Example Bicep Template

Below is a simple example of a Bicep script to deploy an Azure Storage Account:

param storageAccountName string = 'mystorageaccount'
param location string = 'eastus'

resource storageAccount 'Microsoft.Storage/storageAccounts@2021-09-01' = {
  name: storageAccountName
  location: location
  kind: 'StorageV2'
  sku: {
    name: 'Standard_LRS'
  }
}

What is Terraform?

Terraform is an open-source, multi-cloud IaC tool developed by HashiCorp. Unlike Bicep, which is specific to Azure, Terraform supports multiple cloud providers, including AWS, Google Cloud, and Azure. It uses the HashiCorp Configuration Language (HCL) to define infrastructure.

Key Features of Terraform

✔ Multi-cloud support: Works with Azure, AWS, GCP, and on-prem infrastructure.
✔ State management: Keeps track of infrastructure state, allowing for drift detection.
✔ Modular and reusable: Supports modules for reusable infrastructure components.
✔ Extensive ecosystem: Large community with many pre-built modules.
✔ Built-in dependency management: Ensures resources are created in the correct order.

Example Terraform Template

Below is a simple Terraform script to deploy an Azure Storage Account:

provider "azurerm" {
  features {}
}

resource "azurerm_storage_account" "example" {
  name                     = "mystorageaccount"
  resource_group_name      = "my-resource-group"
  location                 = "East US"
  account_tier             = "Standard"
  account_replication_type = "LRS"
}

Terraform’s Multi-Provider Advantage

Terraform is not just multi-cloud but multi-provider, meaning it can be used to provision non-cloud resources such as databases, SaaS applications, Kubernetes clusters, and even on-prem infrastructure.

Examples of Terraform’s Multi-Provider System

• Cloud Providers: Azure, AWS, GCP
• SaaS Platforms: GitHub, Azure DevOps, Datadog, Okta
• Infrastructure: VMware, Cisco, Kubernetes, Helm
• Databases & Storage: PostgreSQL, MySQL, MongoDB, Azure SQL

Example: Provisioning Azure + GitHub Repositories in Terraform

Here’s an example of how Terraform can deploy both an Azure Storage Account and a GitHub repository within the same configuration:

# Azure Provider
provider "azurerm" {
  features {}
}

resource "azurerm_storage_account" "example" {
  name                     = "mystorageaccount"
  resource_group_name      = "my-resource-group"
  location                 = "East US"
  account_tier             = "Standard"
  account_replication_type = "LRS"
}

# GitHub Provider
provider "github" {
  token = var.github_token
}

resource "github_repository" "example_repo" {
  name        = "my-terraform-repo"
  description = "This is managed by Terraform"
  visibility  = "public"
}

With Terraform, this can be deployed in a single pipeline, making it much simpler to manage infrastructure across multiple platforms.

Challenges of Mixing Bicep and Terraform in the Same Pipeline

If you only use Bicep, you might struggle with managing non-Azure resources. In a DevOps pipeline, this creates challenges:

1. Multiple IaC tools: You would need to manage Terraform for non-Azure resources and Bicep for Azure resources separately.
2. Complexity in orchestration: A pipeline would need separate execution steps for Bicep and Terraform.
3. State synchronization issues: Terraform tracks the entire infrastructure in a state file, while Bicep does not, making it harder to maintain consistency.

Example Pipeline with Mixed Bicep and Terraform:

• Step 1: Deploy Azure resources with Bicep
• Step 2: Deploy GitHub repositories with Terraform
• Step 3: Deploy Kubernetes workloads with Helm/Terraform

This makes the pipeline more complex compared to using Terraform alone.

Conclusion: Why Terraform is More Flexible

While Bicep is great for Azure-native infrastructure, Terraform’s multi-provider support makes it a better choice if:

• Your pipeline needs to provision both Azure and non-Azure resources.
• You want to manage SaaS integrations (e.g., GitHub, Azure DevOps, Okta).
• You need a consistent state management approach across all platforms.

If your entire infrastructure is Azure-only, Bicep is a strong choice. But for hybrid or multi-cloud environments, Terraform provides a more unified IaC experience.

Would you like a guide on how to integrate Terraform into an Azure DevOps or GitHub Actions pipeline?