Add API key authentication for Elsa client

Introduced an `ApiKeyHttpMessageHandler` to use an API key as the authorization header for Elsa API client. This ensures secure interaction with the Elsa server. Also made updates to the `ElsaClientOptions` class to include the API key. An `AddElsaClient` method is added with the API key parameter in `DependencyInjectionExtensions` class for convenience.

src/clients/Elsa.Api.Client/Extensions/DependencyInjectionExtensions.cs

@@ -2,6 +2,7 @@
 using System.Text.Json.Serialization;
 using Elsa.Api.Client.Contracts;
 using Elsa.Api.Client.Converters;
+using Elsa.Api.Client.HttpMessageHandlers;
 using Elsa.Api.Client.Options;
 using Elsa.Api.Client.Resources.ActivityDescriptorOptions.Contracts;
 using Elsa.Api.Client.Resources.ActivityDescriptors.Contracts;
@@ -31,6 +32,31 @@ namespace Elsa.Api.Client.Extensions;
 [PublicAPI]
 public static class DependencyInjectionExtensions
 {
+ /// <summary>
+ /// Adds the Elsa client to the service collection.
+ /// </summary>
+ /// <param name="services">The service collection.</param>
+ /// <param name="baseAddress">The base address of the Elsa API.</param>
+ /// <param name="apiKey">The API key to use for authentication.</param>
+ /// <param name="configureOptions">An optional delegate that can be used to configure the client options.</param>
+ /// <param name="configureBuilderOptions">An optional delegate that can be used to configure the client builder options.</param>
+ public static IServiceCollection AddElsaClient(this IServiceCollection services, Uri baseAddress, string apiKey, Action<ElsaClientOptions>? configureOptions = default, Action<ElsaClientBuilderOptions>? configureBuilderOptions = default)
+ {
+ services.AddScoped<ApiKeyHttpMessageHandler>();
+ return services.AddElsaClient(
+ options =>
+ {
+ options.BaseAddress = baseAddress;
+ options.ApiKey = apiKey;
+ configureOptions?.Invoke(options);
+ },
+ configureBuilderOptions: options =>
+ {
+ options.ConfigureHttpClientBuilder = builder => builder.AddHttpMessageHandler<ApiKeyHttpMessageHandler>();
+ configureBuilderOptions?.Invoke(options);
+ });
+ }
+
  /// <summary>
  /// Adds the Elsa client to the service collection.
  /// </summary>

src/clients/Elsa.Api.Client/HttpMessageHandlers/ApiKeyHttpMessageHandler.cs

@@ -0,0 +1,30 @@
+using System.Net.Http.Headers;
+using Elsa.Api.Client.Options;
+using Microsoft.Extensions.Options;
+
+namespace Elsa.Api.Client.HttpMessageHandlers;
+
+/// <summary>
+/// An <see cref="HttpMessageHandler"/> that configures the outgoing HTTP request to use an API key as the authorization header.
+/// </summary>
+public class ApiKeyHttpMessageHandler : DelegatingHandler
+{
+ private readonly ElsaClientOptions _options;
+
+ /// <summary>
+ /// Initializes a new instance of the <see cref="ApiKeyHttpMessageHandler"/> class.
+ /// </summary>
+ public ApiKeyHttpMessageHandler(IOptions<ElsaClientOptions> options)
+ {
+ _options = options.Value;
+ }
+
+ /// <inheritdoc />
+ protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+ {
+ var apiKey = _options.ApiKey;
+ request.Headers.Authorization = new AuthenticationHeaderValue("ApiKey", apiKey);
+
+ return await base.SendAsync(request, cancellationToken);
+ }
+}

src/clients/Elsa.Api.Client/Options/ElsaClientOptions.cs

@@ -9,11 +9,11 @@ public class ElsaClientOptions
  /// Gets or sets the base address of the Elsa server.
  /// </summary>
  public Uri BaseAddress { get; set; } = default!;
- 
+
  /// <summary>
- /// Gets or sets the API key to use when authenticating with the Elsa server.
+ /// Gets or sets the API key function to use when authenticating with the Elsa server.
  /// </summary>
- public string ApiKey { get; set; } = default!;
+ public string? ApiKey { get; set; }
 
  /// <summary>
  /// Gets or sets a delegate that can be used to configure the HTTP client.