Learning Center
March 20, 2024
6 min read

What is a Kubernetes Ingress Controller?

Peter Barnard
Content @ Kong

A Kubernetes Ingress Controller is the combined version of Ingress, Load Balancer, and Gateway API. Using the set of rules and restrictions from the Ingress, the Kubernetes Ingress controller can balance the load of traffic both into and between the Kubernetes cluster. Using the components of a Gateway API like a reverse proxy, the Ingress Controller can also provide security and encryption to the location of the Kubernetes cluster. Kubernetes Ingress Controller is an all-in-one tool that can utilize the beneficial aspects of various Kubernetes components.

Be sure to also check out the prelude to this topic: What is Kubernetes Ingress?

Common use cases for Kubernetes Ingress Controllers

While the convenience of Kubernetes Ingress Controller is a huge incentive, there are a handful of specific use cases where it really shines. Similar to the convenience aspect, it centralizes and simplifies Ingress management for the user. It can monitor and direct all traffic moving in or out of a cluster, assuming roles of Kubernetes Ingress and egress.

The primary responsibilities of a Kubernetes Ingress Controller include:

  1. Traffic Routing: The Ingress Controller reads the rules defined in Ingress resources and routes incoming traffic to the appropriate services based on these rules. It can handle various routing scenarios, such as host-based routing, path-based routing, and traffic splitting.
  2. Load Balancing: The Ingress Controller distributes incoming traffic across multiple replicas of a service, ensuring high availability and scalability. It can use different load balancing algorithms, such as round-robin or least connections, to distribute the load effectively.
  3. SSL/TLS Termination: Many Ingress Controllers support SSL/TLS termination, offloading the encryption/decryption workload from the application services. This allows for secure communication between clients and services within the cluster.
  4. Gateway API Support: Some Ingress Controllers implement the Gateway API, providing support for routing various network protocols, such as TCP, UDP, and HTTP/HTTPS. This enables more advanced routing scenarios and integration with different types of network services.
  5. Health Checking: Ingress Controllers can perform health checks on the backend services to ensure that traffic is only routed to healthy instances, improving overall application availability and reliability.
  6. Canary Deployments: Ingress Controllers can support canary deployments by gradually routing a portion of traffic to a new version of a service, allowing for testing and validation before a full rollout.

Key benefits of using a Kubernetes Ingress Controller

While the many components of Kubernetes Ingress Controllers can be done individually, the main benefit is that it conveniently groups all those features into one control panel. Since everything is all monitored in one place, it’s easy for the user to see real-time metrics on API usage, traffic, and more. For new members, the intuitive interface is quite easy to learn, so there’s no more steep learning curve from managing multiple applications with Kubernetes Ingress Controller.

Additional benefits include:

  1. Centralized Management: By consolidating the functionalities of Ingress, load balancer, and Gateway API, Kubernetes Ingress Controllers provide a centralized management interface for controlling external traffic to services within the cluster.
  2. Simplified Configuration: Ingress Controllers simplify the configuration process by allowing users to define routing rules and policies through Kubernetes resources, rather than managing individual load balancers or proxies.
  3. Improved Observability: Ingress Controllers often provide comprehensive monitoring and logging capabilities, making it easier to track and analyze traffic patterns, performance metrics, and potential issues.
  4. Enhanced Security: Many Ingress Controllers support features like SSL/TLS termination, WAF (Web Application Firewall) integration, and rate limiting, improving the overall security posture of applications exposed through the Ingress.
  5. High Availability and Scalability: Ingress Controllers can distribute traffic across multiple replicas of a service, ensuring high availability and scalability. They also support advanced features like canary deployments and traffic splitting, facilitating controlled rollouts and testing.
  6. Integration with Kubernetes Ecosystem: Ingress Controllers are tightly integrated with the Kubernetes ecosystem, allowing seamless interaction with other Kubernetes resources and leveraging native features like service discovery and load balancing.
  7. Vendor-agnostic: While there are various Ingress Controller implementations, they adhere to the same Kubernetes Ingress specification, allowing for portability and interoperability across different cloud providers and environments.
  8. Community Support: Popular Ingress Controller implementations often have active communities, providing support, documentation, and continuous development and improvement of the project.

How to choose the right Kubernetes Ingress Controller?

With the many options for Kubernetes Ingress Controllers out there, it’s important to understand what specifically to look for when choosing the best fit for the user's needs. Depending on the amount of traffic being brought to a service, it’s crucial to find an Ingress Controller that’s able to deal with traffic both high and low. Also, based on prior level of expertise, having an Ingress Controller that’s capable of synthesizing and simplifying API and security information for the user may be of significant value.

To look toward the future, users want to choose an Ingress Controller that will continue to evolve and adapt as the organization’s needs change. Some Ingress Controllers specialize in commercial usage, while others may be more catered towards open-source projects or casual services. Ultimately, your services and information are indispensable. The ability to implement the correct API for security and encryption is a key feature.

Here are some key factors to consider when selecting an Ingress Controller:

  1. Performance and Scalability: Evaluate the performance capabilities of the Ingress Controller, considering factors such as throughput, connection handling, and resource utilization. Ensure that the Ingress Controller can handle your current and projected traffic volumes, as well as support scalability as your application grows.
  2. Security Features: Security should be a top priority when exposing applications to external traffic. Look for Ingress Controllers that support features like SSL/TLS termination, WAF integration, rate limiting, and integration with authentication and authorization mechanisms.
  3. Observability and Monitoring: Ingress Controllers with robust monitoring and logging capabilities can provide valuable insights into traffic patterns, performance metrics, and potential issues. This can aid in troubleshooting, capacity planning, and overall system visibility.
  4. Integration with Kubernetes Ecosystem: Consider Ingress Controllers that seamlessly integrate with other Kubernetes components and leverage native features like service discovery, load balancing, and autoscaling. This can simplify deployment and management within your Kubernetes environment.
  5. Community and Support: Evaluate the community support and active development behind the Ingress Controller. A vibrant community can provide valuable resources, documentation, and ongoing improvements to the project.
  6. Plugin and Extension Support: Some Ingress Controllers offer the ability to extend functionality through plugins or custom resources. This can be valuable if you have specific requirements or need to integrate with third-party services or tools.
  7. Deployment Options: Evaluate the deployment options available for the Ingress Controller. Some may be better suited for cloud environments, while others may be more suitable for on-premises or hybrid deployments.
  8. API and Configuration Management: Assess the ease of configuring and managing the Ingress Controller through its APIs or user interfaces. A well-designed API and configuration management system can simplify the deployment and maintenance of your Ingress rules and policies.
  9. Commercial Support and Licensing: If you require commercial support or have specific licensing requirements, consider Ingress Controllers offered by vendors that provide enterprise-level support and licensing options.

Kong Ingress Controller

Kong Ingress Controller is one of the many Kubernetes Ingress Controllers out there, but what sets it apart from the others?

Kong is all-in on implementing high networking standards into its Ingress Controller. The Kong Ingress Controller highlights its seamless compatibility with Kong Gateway, the most downloaded API Gateway, allowing for the strong protection of information against all the incoming and outgoing traffic. Kong Ingress Controller makes Ingress and routing resources and directly implements them as a Kong Gateway configuration. In doing this, the user is able to experience all the benefits and applications that are available in Kong Gateway that can be directly used for their Kubernetes Ingress Controller.

Ready to get started? Try Kong Ingress Controller for free.

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