Keycloak integration

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Keycloak logo

Keycloak is an open-source Identity and Access Management solution aimed at modern applications and services. The Keycloak integration enables you to connect to existing Keycloak instances or create new instances from Aspire with the quay.io/keycloak/keycloak container image.

Hosting integration

The Keycloak hosting integration models the server as the KeycloakResource type. To access this type and APIs, add the 📦 Aspire.Hosting.Keycloak NuGet package in your AppHost project:

Install the NuGet package
dotnet add package Aspire.Hosting.Keycloak

Add Keycloak resource

In your AppHost project, call AddKeycloak to add and return a Keycloak resource builder:

var builder = DistributedApplication.CreateBuilder(args);
  
var keycloak = builder.AddKeycloak("keycloak", 8080);
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
                        .WithReference(keycloak)
                        .WaitFor(keycloak);
  
var webfrontend = builder.AddProject<Projects.Web>("webfrontend")
                         .WithExternalHttpEndpoints()
                         .WithReference(keycloak)
                         .WithReference(apiService)
                         .WaitFor(apiService);

Tip

For local development use a stable port for the Keycloak resource (8080 in the preceding example). It can be any port, but it should be stable to avoid issues with browser cookies that will persist OIDC tokens beyond the lifetime of the AppHost.

When Aspire adds a container image to the AppHost, it creates a new Keycloak instance on your local machine. The Keycloak resource includes default credentials:

  • KEYCLOAK_ADMIN: A value of admin
  • KEYCLOAK_ADMIN_PASSWORD: Random password generated using the default password parameter

When the AppHost runs, the password is stored in the AppHost's secret store in the Parameters section:

{
  "Parameters:keycloak-password": "<THE_GENERATED_PASSWORD>"
}

Tip

If you'd rather connect to an existing Keycloak instance, call AddConnectionString instead. For more information, see Reference existing resources.

Add Keycloak resource with data volume

To add a data volume to the Keycloak resource, call the WithDataVolume method on the Keycloak resource:

var builder = DistributedApplication.CreateBuilder(args);
  
var keycloak = builder.AddKeycloak("keycloak", 8080)
                      .WithDataVolume();
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
                        .WithReference(keycloak)
                        .WaitFor(keycloak);

The data volume is used to persist the Keycloak data outside the lifecycle of its container. The data volume is mounted at the /opt/keycloak/data path in the Keycloak container.

Caution

The admin credentials are stored in the data volume. When using a data volume and if the credentials change, it will not work until you delete the volume.

Add Keycloak resource with data bind mount

To add a data bind mount to the Keycloak resource, call the WithDataBindMount method:

var builder = DistributedApplication.CreateBuilder(args);
  
var keycloak = builder.AddKeycloak("keycloak", 8080)
                      .WithDataBindMount(@"C:\Keycloak\Data");
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
                        .WithReference(keycloak)
                        .WaitFor(keycloak);

Note

Data bind mounts have limited functionality compared to volumes, and when you use a bind mount, a file or directory on the host machine is mounted into a container.

Add Keycloak resource with parameters

When you want to explicitly provide the admin username and password used by the container image, you can provide these credentials as parameters:

var builder = DistributedApplication.CreateBuilder(args);
  
var username = builder.AddParameter("username");
var password = builder.AddParameter("password", secret: true);
  
var keycloak = builder.AddKeycloak("keycloak", 8080, username, password);
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
                        .WithReference(keycloak)
                        .WaitFor(keycloak);

For more information on providing parameters, see External parameters.

Add Keycloak resource with realm import

To import a realm into Keycloak, call the WithRealmImport method:

var builder = DistributedApplication.CreateBuilder(args);
  
var keycloak = builder.AddKeycloak("keycloak", 8080)
                      .WithRealmImport("./Realms");
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
                        .WithReference(keycloak)
                        .WaitFor(keycloak);

The realm import files are mounted at /opt/keycloak/data/import in the Keycloak container. Realm import files are JSON files that represent the realm configuration.

Export telemetry to OTLP collector

Keycloak containers can export telemetry to your OTLP collector using the WithOtlpExporter method:

var builder = DistributedApplication.CreateBuilder(args);
  
var keycloak = builder.AddKeycloak("keycloak", 8080)
    .WithOtlpExporter();
  
var apiService = builder.AddProject<Projects.ApiService>("apiservice")
    .WithReference(keycloak)
    .WaitFor(keycloak);

This enables Keycloak to send traces, metrics, and logs to the Aspire dashboard, providing better observability for your authentication flows.

Hosting integration health checks

The Keycloak hosting integration doesn't currently support health checks, nor does it automatically add them.

Client integration

To get started with the Keycloak client integration, install the 📦 Aspire.Keycloak.Authentication NuGet package in your ASP.NET Core project:

Install the NuGet package
dotnet add package Aspire.Keycloak.Authentication

The Keycloak client integration registers JwtBearer and OpenId Connect authentication handlers in the DI container for connecting to a Keycloak server.

Add JWT bearer authentication

In the Program.cs file of your ASP.NET Core API project, call the AddKeycloakJwtBearer extension method to add JwtBearer authentication:

builder.Services.AddAuthentication()
                .AddKeycloakJwtBearer(
                    serviceName: "keycloak",
                    realm: "api",
                    options =>
                    {
                        options.Audience = "store.api";
  
                        // For development only - disable HTTPS metadata validation
                        // In production, use explicit Authority configuration instead
                        if (builder.Environment.IsDevelopment())
                        {
                            options.RequireHttpsMetadata = false;
                        }
                    });

Caution

When using RequireHttpsMetadata = true (the default), the JWT Bearer authentication requires the Authority URL to use HTTPS. However, Aspire service discovery uses the https+http:// scheme, which doesn't satisfy this requirement. For production scenarios where HTTPS metadata validation is required, you need to explicitly configure the Authority URL.

Add OpenId Connect authentication

In the Program.cs file of your API-consuming project (for example, Blazor), call the AddKeycloakOpenIdConnect extension method to add OpenId Connect authentication:

builder.Services.AddAuthentication(OpenIdConnectDefaults.AuthenticationScheme)
                .AddKeycloakOpenIdConnect(
                    serviceName: "keycloak",
                    realm: "api",
                    options =>
                    {
                        options.ClientId = "StoreWeb";
                        options.ResponseType = OpenIdConnectResponseType.Code;
                        options.Scope.Add("store:all");
                    });

Production considerations

When deploying Keycloak authentication to production environments, there are several important security considerations:

HTTPS metadata requirements

By default, JWT Bearer authentication in ASP.NET Core has RequireHttpsMetadata = true, which requires that the Authority URL uses HTTPS.

For production scenarios, configure the Authority URL explicitly:

builder.Services.AddAuthentication()
    .AddKeycloakJwtBearer(
        serviceName: "keycloak",
        realm: "MyRealm",
        configureOptions: options =>
        {
            // Explicitly set the Authority for production
            if (!builder.Environment.IsDevelopment())
            {
                options.Authority = "https://your-keycloak-server.com/realms/MyRealm";
            }
  
            options.Audience = "my.api";
        });

Connection string configuration

For production deployments, consider using connection strings:

// In AppHost.cs
builder.AddConnectionString("keycloak", "https://your-keycloak-server.com");

Security best practices

  • Always use RequireHttpsMetadata = true in production environments
  • Use secure, validated SSL certificates for your Keycloak server
  • Configure appropriate realm settings and client configurations in Keycloak
  • Implement proper token validation and audience checks
  • Consider using Keycloak's built-in security features like rate limiting and brute force protection
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