How to get azure token using c# client?

Question

I am trying to get all vm size name from my Azure account and I am using This approach In site when I click try out I am getting back result which I need.

Json look like:

{
  "value": [
    {
      "name": "Standard_D1_v2",
      "numberOfCores": 1,
      "osDiskSizeInMB": 1047552,
      "resourceDiskSizeInMB": 51200,
      "memoryInMB": 3584,
      "maxDataDiskCount": 4
    },
    {
      "name": "Standard_D2_v2",
      "numberOfCores": 2,
      "osDiskSizeInMB": 1047552,
      "resourceDiskSizeInMB": 102400,
      "memoryInMB": 7168,
      "maxDataDiskCount": 8
    },
}

And after logged in microsoft gets token and request looks like:

GET https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Compute/locations/North%20Europe/vmSizes?api-version=2019-12-01
Authorization: Bearer {{token.....}}

I need to get token for making request which I don't know, I have credentials like:

azure_client_id azure_client_secret azure_tenant_id azure_subscription_id

Using this credentials how can I achieve this json result, in short how can I get token.

Tried approaches:

This one Read this but no info investigated also this one also this question in stackoveflow

P.S. I am using aspnet core 3.1 web app maybe it is better client for azure. I used ComputeClient but no success. In final I thought using httpclient but first of all I need to test with postman.

Answer 1

If you want to manage Azure resource with a service principal, we need to assign Azure RABC role to the service principal, such as Contributor.

For example

1. Create service principal and assign Azure RABC role to it. Since you want to list Azure VM size, we can use the role Virtual Machine Contributor.

az login
az account set --subscription "<your subscription id>"

az ad sp create-for-rbac -n "readMetric" --role "Virtual Machine Contributor"

2. Get token

POST /<your AD tenant domain>/oauth2/v2.0/token HTTP/1.1
Host: login.microsoftonline.com
Content-Type: application/x-www-form-urlencoded

grant_type =client_credentials
&client_id=<>
&client_secret=<>
&scope=https://management.azure.com/.default

3. List Azure VM size

GET https://management.azure.com/subscriptions/{subscriptionId}/providers/Microsoft.Compute/locations/eastus/vmSizes?api-version=2019-12-01
Authorization: Bearer {{token.....}}

4. .Net Core With Azure Net SDK Microsoft.Azure.Management.Compute.Fluent

AzureCredentials credentials = SdkContext.AzureCredentialsFactory.FromServicePrincipal(
                      clientId, // the sp appId
                      clientSecret, // the sp password
                      tenantId, // the sp tenant  
                       AzureEnvironment.AzureGlobalCloud);
            RestClient restClient = RestClient.Configure()
                                   .WithEnvironment(AzureEnvironment.AzureGlobalCloud)
                                   .WithCredentials(credentials)
                                   .WithLogLevel(HttpLoggingDelegatingHandler.Level.Basic)
                                   .Build();
            ComputeManagementClient client = new ComputeManagementClient(restClient);
            client.SubscriptionId = subscriptionId;// the subscription you use

           var vmSizes= await client.VirtualMachineSizes.ListAsync("eastus");
            foreach (var vmSize in vmSizes) {

                Console.WriteLine("The VM Size Name : "+ vmSize.Name);


            }