What is Ingress
In Kubernetes, ingress is a way to expose HTTP and HTTPS services running within a cluster to the outside world. It acts as a traffic controller for incoming traffic to a cluster, routing requests to the appropriate service based on the requested URL.
Ingress resources define rules for how incoming requests should be directed to specific services within the cluster. These rules can be based on the requested URL, HTTP headers, or other criteria.
In order for ingress to work, an ingress controller must be running in the cluster. The ingress controller is responsible for implementing the rules defined in the ingress resources and forwarding traffic to the appropriate services.
Some popular ingress controllers for Kubernetes include Nginx, Traefik, and Istio.
Why we need Ingress
In Kubernetes, ingress provides several benefits, including:
Load balancing: Ingress can balance incoming traffic across multiple services within a cluster, helping to ensure that no single service becomes overwhelmed by requests.
Flexible routing: Ingress allows for flexible routing of traffic to different services based on the requested URL, HTTP headers, or other criteria.
SSL termination: Ingress can terminate SSL (Secure Sockets Layer) connections at the edge of the cluster, reducing the load on the backend services and simplifying certificate management.
Centralized management: Ingress resources allow for the centralized management of ingress rules for all services within a cluster, simplifying configuration and reducing the risk of errors.
Security: Ingress can provide an additional layer of security by blocking unauthorized traffic or by limiting access to certain services based on authentication or authorization rules.
Overall, ingress provides a powerful and flexible way to manage incoming traffic to a Kubernetes cluster, making it easier to expose services to the outside world while also ensuring that traffic is directed to the appropriate services and resources.
comparison of k8s-provided ingress and another cloud provided ingress controller
Kubernetes provides a default Ingress controller, which is a basic implementation of Ingress using the Nginx web server. This Ingress controller can be used in any Kubernetes cluster, regardless of the cloud provider or hosting platform.
On the other hand, cloud providers also offer their own Ingress controllers that are specifically designed to work with their cloud infrastructure. These Ingress controllers may offer additional features and integration with other cloud services.
Here are some general comparisons between Kubernetes-provided ingress and cloud-provided ingress controllers:
Features: Cloud providers often offer more advanced features in their Ingress controllers, such as automatic TLS certificate management and integration with other cloud services like load balancers and DNS. However, these features may be more limited or not available in the default Kubernetes Ingress controller.
Ease of use: The default Kubernetes Ingress controller is relatively simple to set up and use, and it works the same way across all platforms. Cloud-provided Ingress controllers may have more complex setup procedures and may be different between cloud providers.
Performance: Both the Kubernetes-provided Ingress controller and cloud-provided Ingress controllers should offer similar performance since they both rely on the same Kubernetes API for configuration. However, the specific implementation and resource allocation may vary between providers.
Cost: Using a cloud-provided Ingress controller may incur additional costs depending on the provider and features used. The default Kubernetes Ingress controller is free to use and can be used on any platform.
Overall, the choice between using the default Kubernetes Ingress controller or a cloud-provided Ingress controller depends on your specific needs and requirements, such as feature requirements, ease of use, performance, and cost.
Load Balancer IP vs Ingress
Load balancer IP and Ingress are both ways to expose services in a Kubernetes cluster to the outside world. However, they differ in several ways:
Traffic routing: Load balancer IP routes traffic to a single service, whereas Ingress can route traffic to multiple services based on the requested URL or other criteria.
Protocol support: Load balancer IP can route any TCP or UDP traffic to a service, whereas Ingress is specifically designed for HTTP and HTTPS traffic.
Layer: Load balancer IP operates at the transport layer (TCP/UDP), while Ingress operates at the application layer (HTTP/HTTPS).
Flexibility: Ingress provides more flexibility in routing traffic and applying custom rules based on the requested URL, HTTP headers, or other criteria.
Cost: Load balancer IP typically incurs additional costs for the use of a cloud-provided load balancer service. Ingress is free to use and can be implemented using the default Kubernetes Ingress controller or a cloud-provided Ingress controller.
In summary, Load Balancer IP and Ingress serve different purposes in Kubernetes. Load Balancer IP provides a simple way to expose a single service to the outside world, while Ingress provides more flexibility in routing traffic to multiple services based on custom rules.
What is Ingress Controller
Ingress Controller is a component of Kubernetes that is responsible for implementing the Ingress resource and routing external traffic to the appropriate services in the cluster.
When an Ingress resource is created, the Ingress Controller reads the rules defined in the resource and configures the load balancer or reverse proxy to route traffic to the appropriate backend services based on the specified routing rules.
The Ingress Controller can be implemented using different technologies, such as Nginx, Traefik, Istio, or a cloud-provided load balancer. The implementation can be chosen based on the specific requirements and features needed.
In addition to implementing Ingress resources, Ingress Controllers can also provide additional features, such as SSL termination, traffic rate limiting, load balancing algorithms, and integration with other cloud services.
Overall, the Ingress Controller plays a critical role in managing external traffic to a Kubernetes cluster and providing a flexible and scalable way to expose services to the outside world.
Different types of Ingress Controllers
There are different types of Ingress Controllers available for Kubernetes, each with its own set of features, advantages, and limitations. Here are some examples:
Nginx Ingress Controller: This is the most widely used Ingress Controller for Kubernetes. It is an open-source implementation of Ingress using the Nginx web server as a reverse proxy. It is highly configurable and supports SSL termination, TCP/UDP traffic, and multiple load balancing algorithms.
Traefik Ingress Controller: Traefik is a popular open-source Ingress Controller that is designed for cloud-native environments. It supports automatic discovery of services and routes traffic dynamically based on the requested URL or other criteria. It also supports SSL termination, circuit breakers, and integration with other cloud services.
Istio Ingress Controller: Istio is a service mesh that provides advanced traffic management features, such as traffic routing, load balancing, and service-level authentication. Istio Ingress Controller is a part of Istio and provides advanced features such as rate limiting, retries, and service-to-service authentication.
Kong Ingress Controller: Kong is a cloud-native API gateway that provides advanced traffic management features, such as traffic routing, load balancing, and API security. Kong Ingress Controller is a part of Kong and provides advanced features such as authentication, rate limiting, and plugins for extending functionality.
Cloud Provider Ingress Controllers: Cloud providers such as AWS, GCP, and Azure offer their own Ingress Controllers that are designed to work seamlessly with their cloud infrastructure. These Ingress Controllers provide advanced features such as automatic TLS certificate management, integration with load balancers, and CDN integration.
Overall, the choice of Ingress Controller depends on the specific requirements and features needed for your Kubernetes cluster. The Nginx Ingress Controller is a good default choice, but other controllers may be more suitable depending on the use case.