go-azure-api

Experimental REST API to query Azure resources, written in Go

Overview

This is a simple REST API that calls Azure Management (ARM) endpoints to retrieve information about Azure resources.

Features

• List all resource groups in an Azure subscription
• Uses Azure SDK for Go v2
• Supports multiple authentication methods via DefaultAzureCredential

Prerequisites

• Go 1.21 or later
• Azure subscription
• Azure CLI installed and authenticated, OR service principal credentials

Setup

1. Install dependencies:

go mod download

2. Set up authentication:

   • Option 1 (Recommended for local development): Sign in with Azure CLI:

     az login

   • Option 2: Set up service principal environment variables (see .env.example)

3. Set your Azure subscription ID:

export AZURE_SUBSCRIPTION_ID="your-subscription-id-here"

You can find your subscription ID by running:

az account show --query id -o tsv

Running the API

go run main.go

The server will start on port 8080 by default.

API Endpoints

GET /

Returns API information and available endpoints.

curl http://localhost:8080/

GET /resource-groups

Returns all resource groups in the configured subscription.

curl http://localhost:8080/resource-groups

Example response:

{
  "subscription_id": "12345678-1234-1234-1234-123456789abc",
  "count": 2,
  "resource_groups": [
    {
      "id": "/subscriptions/12345678-1234-1234-1234-123456789abc/resourceGroups/my-rg",
      "location": "eastus",
      "name": "my-rg",
      "tags": {
        "environment": "dev"
      }
    }
  ]
}

GET /health

Health check endpoint.

curl http://localhost:8080/health

Environment Variables

• AZURE_SUBSCRIPTION_ID (required): Your Azure subscription ID
• PORT (optional): Server port, defaults to 8080
• AZURE_TENANT_ID, AZURE_CLIENT_ID, AZURE_CLIENT_SECRET (optional): For service principal authentication

Building

go build -o go-azure-api
./go-azure-api

Authentication Methods

The application uses DefaultAzureCredential which attempts authentication in the following order:

1. Environment variables (service principal)
2. Workload identity (for Azure Kubernetes Service)
3. Managed identity (for Azure VMs, App Service, etc.)
4. Azure CLI credentials
5. Azure PowerShell credentials

For local development, using Azure CLI (az login) is the easiest method.