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Getting Started with Keycloak: A Beginner’s Guide


In a microservices architecture, ensuring the security of applications and services (APIs) is importent. Unauthorized access to protected data can potentially cost millions of dollars in banking and financial IT companies. User authentication, authorization, and identity management are critical aspects of securing web and mobile applications for these companies. This is where Keycloak comes into play.

This in this article I will walk you through the fundamentals of Keycloak, what is keycloak is, Key features, why do we need to use it, where do we use it, By the end of this guide, you'll have a solid understanding of how to leverage Keycloak to enhance the security and usability of your microservices applications.

What is Keycloak?

Keycloak is an open-source identity and access management (IAM) solution developed by Red Hat. It offers a robust and flexible framework for securing your applications and services with modern authentication and authorization mechanisms, particularly beneficial in microservices architecture.

Keycloak simplifies the process of managing user identities, ensuring only authorized users can access your resources. Whether you're developing a single-page web application, a mobile app, or a complex microservices architecture, Keycloak offers a centralized and highly customizable solution for handling authentication and access control.

Key Features

Here are the Keycloak's main features in the context of modern web and mobile applications and microservices architectures.

  1. Single Sign-On (SSO): Keycloak enables users to sign in once and gain access to multiple applications without the need to re-enter their credentials.

  2. Open source: Keycloak is an open-source project, making it accessible and customizable for various use cases.

  3. User federation: Keycloak can integrate with external identity providers, such as LDAP, Active Directory, or social media platforms, allowing you to leverage existing user databases and credentials.

  4. Role-Based Access Control: You can define fine-grained access control by assigning roles and permissions to users and applications, ensuring that users only access the resources they are authorized to.

  5. Multi-Factor authentication (MFA): Enhance security by implementing MFA, requiring users to provide multiple forms of verification before gaining access.

  6. OAuth 2.0 and openID connect: Keycloak supports modern identity and authorization protocols, making it suitable for both traditional and modern web application development.

  7. multi-tenant support: which allows you to efficiently manage and secure multiple tenants or organizations within a single Keycloak instance, providing isolation and customized access control for each tenant.

  8. Scalability and high availability: Keycloak can be deployed in a scalable and highly available configuration, making it suitable for enterprise-level applications.

Installing Keycloak

Setting up Keycloak can be done in various ways depending on your specific requirements and preferences. Here are some different methods and deployment options for setting up Keycloak:

  1. Running as a container on Docker: Keycloak is available as an official Docker image on Docker Hub. You can run Keycloak in a Docker container, making it easy to deploy and manage. Docker Compose can also be used for multi-container setups. This approach will also provides full control over the configuration and allows you to customize Keycloak to your needs.

  2. Running Keycloak on Kubernetes: Deploying Keycloak on Kubernetes is another popular choice for container orchestration. Kubernetes provides scalability, high availability, and ease of management. Helm charts are available to simplify deployment on Kubernetes.

  3. Installing and running Keycloak locally: Keycloak provides a standalone server distribution that's easy for developers to set up on their local development machines. This is useful for testing and development purposes.

When to use and when not to use Keycloak?

Keycloak is a powerful identity and access management (IAM) solution, but it may not be the best fit for every situation. Here's when you should consider using Keycloak and when you might want to explore other options:

When to Use Keycloak:

  1. Multi-application environments: Use Keycloak when you have multiple applications or microservices that need centralized authentication and authorization. Keycloak allows you to manage user access across various applications from a single point.

  2. Single Sign-On (SSO) requirements: Keycloak is a good choice when you want to implement single sign-on (SSO) across multiple applications, allowing users to log in once and access multiple services without re-entering credentials.

  3. Open standards: If you prefer using open standards like OAuth 2.0, OpenID Connect, and SAML for identity and access management, Keycloak supports these protocols, making it suitable for integrating with a wide range of platforms and applications.

  4. Customization: When you need a flexible IAM solution that you can customize extensively to meet your organization's specific requirements, Keycloak offers a high degree of customization through its configuration options and extension points.

  5. Open source preference: If you prefer open-source solutions with no licensing costs, Keycloak is open-source and can be a cost-effective option.

  6. Enterprise needs: Red Hat Single Sign-On (RH-SSO), based on Keycloak, is a suitable choice for enterprises requiring commercial support, certification, and integration with other Red Hat products.

  7. Security and compliance: When security and compliance are paramount, Keycloak provides features for securing applications, auditing user activities, and enforcing access controls, helping you meet regulatory requirements.

When Not to Use Keycloak:

  1. Simple authentication: For simple applications or websites that require basic authentication but don't need extensive identity management features, implementing a custom authentication solution or using a lightweight framework might be more straightforward and efficient.

  2. Lightweight requirements: If your project has minimal authentication and authorization needs and you don't require features like SSO, fine-grained access control, or user federation, using a full-fledged IAM solution like Keycloak might be overkill. You could opt for simpler authentication methods or third-party authentication providers.

  3. Legacy systems: In situations where integrating modern IAM solutions is challenging due to legacy systems or complex infrastructure, you may need to consider alternatives that can work more seamlessly with your existing setup.

High-level architecture of Keycloak

Here are the key architectural components of Keycloak:

  • Keycloak server: The core component of Keycloak is the Keycloak Server itself. It is responsible for managing user identities, enforcing authentication and authorization policies, and serving as the central hub for all identity-related operations.

  • Realms: Realms are isolated security domains within Keycloak. Each realm defines its own set of users, roles, policies, and authentication settings. Realms are used to separate and organize different applications or services.

  • Clients: Clients represent applications or services that interact with Keycloak for authentication and authorization. Each client is associated with a specific realm and defines how the application interacts with Keycloak, including configuration details and security settings.

  • Users and identity providers: Keycloak allows you to manage user accounts directly within realms. You can also integrate external identity providers (IdPs), such as LDAP, Active Directory, or social media logins, to federate user identities.

  • Authentication flows: Authentication flows define the steps and mechanisms used to authenticate users. Keycloak supports various authentication methods and allows you to customize the flows to meet your security requirements.

  • Authorization policies: Authorization policies specify access control rules for protecting resources. Keycloak enables you to define policies based on roles, attributes, or custom logic, ensuring that only authorized users can access specific resources.

  • Tokens: Keycloak issues tokens, such as access tokens and ID tokens, to represent user authentication and authorization. These tokens are used by clients to access protected resources and services.

  • Single Sign-On (SSO): Keycloak provides single sign-on capabilities, allowing users to log in once and gain access to multiple applications without the need to re-enter credentials. SSO enhances user experience and security.

  • Adapters and libraries: Keycloak offers adapters and libraries for various programming languages and frameworks (e.g., Java, Node.js, Spring Boot). These components facilitate integration with Keycloak, enabling your applications to participate in the authentication and authorization process.

  • Administration console: The Keycloak Administration Console is a web-based interface for administrators to configure and manage realms, clients, users, roles, authentication flows, and other Keycloak settings.

What is Keycloak Admin Console?

The Keycloak Admin Console is a web-based administrative interface provided by Keycloak for managing and configuring the identity and access management (IAM) system. It serves as the primary graphical user interface (GUI) for administrators, allowing them to perform various tasks related to the setup and maintenance of Keycloak realms, clients, users, roles, authentication flows, and other IAM components for securing applications and services.

Key features and functions of the Keycloak Admin Console include:

  • Realm management: Administrators can create, configure, and manage realms. Realms are isolated security domains that define user stores, authentication settings, and authorization policies for different applications or services.

  • Client configuration: Within each realm, administrators can define client applications and configure their settings, including authentication methods, redirect URIs, and fine-grained security policies.

  • User management: Users and their attributes can be managed within realms. Administrators can create, modify, or delete user accounts, as well as perform actions like resetting passwords and enabling or disabling users.

  • Role management: Keycloak allows the creation of roles and role-based access control (RBAC) policies. Administrators can assign roles to users and specify which roles have access to specific resources.

  • Authentication Flows: Administrators can customize and configure authentication flows for realms, defining how users authenticate and which authentication methods are used during login.

  • Token configuration: Settings related to access tokens, refresh tokens, and identity tokens can be adjusted to meet security and performance requirements.

  • Client scopes: Administrators can create and manage client scopes, which define the attributes and permissions associated with clients. Client scopes can be assigned to clients to influence their behavior.

  • Sessions and Single Sign-On (SSO): Administrators can monitor user sessions, including active sessions, and manage single sign-on settings to enhance user experience and security.

  • Logs and auditing: Keycloak provides logs and audit records within the Admin Console for administrators to track system events, user activities, and authentication events.

  • Security configuration: Security settings, such as password policies, brute-force protection, and token validation, can be configured to ensure the IAM system's security.

  • Themes and customization: The Admin Console's look and feel can be customized through themes and branding to match an organization's visual identity.

  • User federation: Administrators can configure user federation with external identity providers (IdPs) within realms, enabling the integration of LDAP, Active Directory, social media logins, and more.

  • Realm export and import: Keycloak allows administrators to export realm configurations and import them into other Keycloak instances, simplifying deployment and migration tasks.