Azure Footprint Collector Code Tour

This Go program allows you to explore Azure resources by listing available subscriptions, selecting resource groups within those subscriptions, and viewing details for virtual machines within the selected resource groups. The program utilizes the Azure SDK for Go and demonstrates an interactive CLI tool for navigating Azure resources.

Prerequisites

• Go: Ensure you have Go installed. Install Go if you haven't.
• Azure Subscription: You need an Azure account with access to at least one subscription.
• Azure CLI: Although not required, you may want to have Azure CLI installed and authenticated for easier troubleshooting.

Installation

Clone this repository and navigate to the project directory:

git clone <repository-url>
cd <project-directory>

Install the required Go packages:

go mod tidy

Usage

Run the program:

go run azure_footprint.go

The program will guide you through the following steps:

1. Select an Azure Subscription: Lists available subscriptions and prompts you to select one by entering its corresponding number.
2. Select a Resource Group: Lists resource groups within the selected subscription and prompts for selection.
3. Select a Virtual Machine: Lists VMs in the selected resource group and prompts for selection.
4. View VM Details: Displays details of the selected VM, including its name, location, and size.

Example output:

Available Subscriptions:
[0] Azure subscription 1 (64d93d73-b769-41ef-879b-e587f5f86f6c)
Select a subscription by number: 0
Selected subscription: Azure subscription 1 (64d93d73-b769-41ef-879b-e587f5f86f6c)

Available Resource Groups:
[0] resourceGroup1
[1] resourceGroup2
Select a resource group by number: 0
Selected resource group: resourceGroup1

Available VMs:
[0] MyVM1
[1] MyVM2
Select a VM by number: 1
Selected VM: MyVM2

VM Information:
Name: MyVM2
Location: westus
Size: Standard_B2s

Code Walkthrough

Main Function

func main() {
	// Initialize Azure credential
	cred, err := azidentity.NewDefaultAzureCredential(nil)
	if err != nil {
		log.Fatalf("Failed to create credential: %v", err)
	}
	ctx := context.Background()

	// List subscriptions and prompt for selection
	subscriptions, err := listSubscriptions(ctx, cred)
	...
}

The main function initializes the Azure credentials using azidentity.NewDefaultAzureCredential, which automatically handles authentication using environment variables, Azure CLI credentials, or managed identities.

List Subscriptions

func listSubscriptions(ctx context.Context, cred *azidentity.DefaultAzureCredential) ([]*armsubscriptions.Subscription, error) {
	client, err := armsubscriptions.NewClient(cred, nil)
	...
}

The listSubscriptions function uses the armsubscriptions.NewClient to create a subscription client and retrieve all subscriptions associated with the authenticated account. It returns a slice of Subscription pointers, which includes details like DisplayName and SubscriptionID.

Select a Subscription

In main, the program prompts the user to select a subscription by displaying a numbered list. The chosen subscription is used for all subsequent resource queries.

for i, sub := range subscriptions {
	fmt.Printf("[%d] %s (%s)\n", i, *sub.DisplayName, *sub.SubscriptionID)
}
fmt.Print("Select a subscription by number: ")
var subIndex int
fmt.Scanln(&subIndex)

List Resource Groups

func listResourceGroups(ctx context.Context, cred *azidentity.DefaultAzureCredential, subscriptionID string) ([]*armresources.ResourceGroup, error) {
	rgClient, err := armresources.NewResourceGroupsClient(subscriptionID, cred, nil)
	...
}

The listResourceGroups function creates a ResourceGroupsClient using the selected subscriptionID. It retrieves all resource groups within the subscription, and the main function then prompts the user to choose one.

List Virtual Machines in the Resource Group

func listVMs(ctx context.Context, cred *azidentity.DefaultAzureCredential, subscriptionID, resourceGroup string) ([]*armcompute.VirtualMachine, error) {
	vmClient, err := armcompute.NewVirtualMachinesClient(subscriptionID, cred, nil)
	...
}

The listVMs function creates a VirtualMachinesClient and retrieves all VMs within the specified resource group. The main function then lists these VMs for the user to select.

Retrieve VM Details

func getVMInfo(ctx context.Context, cred *azidentity.DefaultAzureCredential, subscriptionID, resourceGroup, vmName string) (*armcompute.VirtualMachine, error) {
	vmClient, err := armcompute.NewVirtualMachinesClient(subscriptionID, cred, nil)
	...
}

The getVMInfo function fetches detailed information about a selected VM using its name and resource group. It returns the VirtualMachine struct, containing attributes such as Name, Location, and HardwareProfile.VMSize.

Error Handling

Each function handles errors by returning them to the caller. The main function logs errors and exits on failure, ensuring that errors are visible and informative.

Dependencies

This project uses the Azure SDK for Go and its relevant packages:

• azidentity for authentication
• armsubscriptions for subscriptions management
• armresources for resource group management
• armcompute for virtual machine management

Next Steps

This project provides a basic CLI tool for exploring Azure resources. You can extend it by adding more features, such as listing other types of resources, starting/stopping VMs, or deploying new resources.

Resources

• Azure SDK for Go

License

This project is licensed under the MIT License - see the LICENSE file for details.