AzureExportTemplate.cs

using Azure.Core;
using Azure.Identity;
using System.Net.Http.Headers;
using System.Net.Http.Json;
using System.Text.Json;
using System.Text.Json.Serialization;

var apiMap = new Dictionary<string, (string ApiVersion, string ResourceIdFormatString)> {
    { "subnets", ("2022-11-01", "Microsoft.Network/virtualNetworks/{0}/subnets/{1}") },
    { "virtualMachines", ("2023-03-01", "Microsoft.Compute/virtualMachines/{0}") },
    { "virtualMachineScaleSets", ("2023-03-01", "Microsoft.Compute/virtualMachineScaleSets/{0}") },
};

var api = apiMap["virtualMachineScaleSets"];
var baseUri = "https://management.azure.com/";
var scope = "https://management.azure.com/.default";
var resourceGroupName = "byteterrace";
var subscriptionId = "f29ec19d-daae-4062-81c3-b80630a3dc2a";
var exportUri = string.Format($"subscriptions/{subscriptionId}/resourcegroups/{resourceGroupName}/providers/{api.ResourceIdFormatString}?api-version={api.ApiVersion}", "byteterrace");
var requestContext = new TokenRequestContext(scopes: new[] { scope, });
var tokenCredential = new DefaultAzureCredential();
var accessToken = tokenCredential.GetToken(requestContext: requestContext).Token;
var jsonSerializerOptions = new JsonSerializerOptions {
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase,
    WriteIndented = true,
};

using var httpClient = new HttpClient();

httpClient.BaseAddress = new Uri(uriString: baseUri);
httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue(parameter: accessToken, scheme: "Bearer");

var result = httpClient
    .GetAsync(requestUri: exportUri)
    .GetAwaiter()
    .GetResult()
    .Content
    .ReadFromJsonAsync<GenericResource>(options: jsonSerializerOptions)
    .GetAwaiter()
    .GetResult()!
    .As<object>(converter: resource => {
        var properties = resource.Properties!;
        var virtualMachineProfile = properties[key: "virtualMachineProfile"].Deserialize<IDictionary<string, JsonElement>>()!;
        var operatingSystemProfile = virtualMachineProfile[key: "osProfile"].Deserialize<IDictionary<string, JsonElement>>()!;
        var operatingSystemConfiguration = (operatingSystemProfile.ContainsKey(key: "linuxConfiguration") ?
                operatingSystemProfile[key: "linuxConfiguration"] :
                operatingSystemProfile[key: "windowsConfiguration"]
            )
            .Deserialize<IDictionary<string, JsonElement>>()!;

        return new {
            Identity = resource.Identity?.ToShim(),
            IsGuestAgentEnabled = operatingSystemConfiguration[key: "provisionVMAgent"].GetBoolean(),
            LicenseType = virtualMachineProfile[key: "licenseType"].GetString(),
            Location = resource.Location,
            Name = resource.Name,
        };
    });
var resultJson = JsonSerializer.Serialize(options: jsonSerializerOptions, value: result);

Console.WriteLine("Done.");

class GenericResource
{
    public string? ApiVersion { get; init; }
    public string? Etag { get; init; }
    public string? Id { get; init; }
    public ResourceIdentity? Identity { get; init; }
    public string? Location { get; init; }
    public string? Name { get; init; }
    public IDictionary<string, JsonElement>? Properties { get; init; }
    public ResourceSku? Sku { get; init; }
    public IDictionary<string, string>? Tags { get; init; }
    public string? Type { get; init; }

    public U As<U>(Func<GenericResource, U> converter) => converter(arg: this);
}
class ResourceId
{
    private string? m_id;

    [JsonIgnore]
    public string? Id {
        get => m_id;
        init {
            m_id = value;

            if (value is not null) {
                var idParts = value.Split("/");

                Name = idParts[^1];
                ProviderName = idParts[6];
                ResourceGroupName = idParts[4];
                SubscriptionId = idParts[2];
                TypeName = idParts[7];
            }
        }
    }
    public string? Name { get; init; }
    public string? ResourceGroupName { get; init; }
    [JsonIgnore]
    public string? ProviderName { get; init; }
    public string? SubscriptionId { get; init; }
    [JsonIgnore]
    public string? TypeName { get; init; }
}
class ResourceIdentity
{
    public string? Type { get; init; }
    public IDictionary<string, JsonElement>? UserAssignedIdentities { get; init; }

    public ResourceIdentityShim ToShim() => new() {
        Type = Type,
        UserAssignedIdentities = (UserAssignedIdentities?.Select(kvp => new ResourceId { Id = kvp.Key, }) ?? default)
    };
}
class ResourceIdentityShim {
    public string? Type { get; init; }
    public IEnumerable<ResourceId>? UserAssignedIdentities { get; init; }
}
class ResourceSku
{
    public int? Capacity { get; init; }
    public string? Family { get; init; }
    public string? Name { get; init; }
    public string? Tier { get; init; }
}