Introducción a Istio Ingress

What are the Kubernetes service types?

Kubernetes is a powerful tool for managing containers in the cloud, and understanding the types of services it provides is critical to optimizing communication within clusters. Below, we explore the main types of services Kubernetes provides, and when it's best to use them.

What is IP Clustering?

Cluster IP is one of the base services in Kubernetes. When using Cluster IP, an internal IP address is assigned to a service, allowing it to be accessible only within the Kubernetes cluster. It is especially useful for services that do not need to communicate with the outside, such as in applications like Online Boutique, where only the frontend exposes its service to the outside. Internal services communicate with each other, such as inventory, currency and checkout, using Cluster IP.

How does NodePort work?

When you need services to be accessible from outside the cluster, but do not want to create a Load Balancer, the NodePort option maps a port on each node in the cluster to a specific service. Requests arriving at any node can be redirected to a specific pod via IP Tables rules configured by QProxy. Although it may be less efficient than other solutions, it is suitable for internal environments such as a Virtual Private Cloud (VPC).

Why use Load Balancer?

To expose a service directly to the internet, the Load Balancer service type is the simplest solution. In Google Kubernetes Engine (GKE), this generates a Google Cloud load balancer with a unique IP, allowing you to direct traffic from the internet to your services. However, it is important to be cost conscious, as each service exposed with a Load Balancer will incur charges for the IP and balancing service.

What is Ingress and how is it used?

Ingress itself is not a type of service, but a resource that provides intelligent rules to manage traffic. It behaves like a router, allowing a single entry to the cluster and is able to handle routes based on headers, hostnames or URLs.

How to configure an Ingress Gateway?

Configuring an Ingress Gateway in GKE is a simple process. First, the gateway name is defined in the metadata, which will be crucial for later steps. A selector is used to bind a specific port. The Ingress Gateway also offers advanced features such as SSL and authorization rules. Usually you will need to set up a wildcard for demonstration or test environments and specify virtual services for routing traffic.

apiVersion: networking.istio.io/v1alpha3kind: Gatewaymetadata: name:  frontend-gatewayspec: selector: istio: ingressgateway servers: - port: number: 80 name: http protocol: HTTP hosts: - "*"---apiVersion: networking.istio.io/v1alpha3kind: VirtualServicemetadata: name:  frontend-ingressspec: hosts: - "*" gateways: -  frontend-gateway http: - match: - port: 80 route: - destination: host: frontend

What are Destination Rules?

Destination Rules allow you to define policies on how traffic to a service should be handled. This is useful for canary deployments, distributing traffic between different versions of a service. Destination Rules make it easy to specify rules on how and how much traffic should go to each version.

How are services monitored in Kubernetes?

Observability is key to managing services in Kubernetes. Tools like Anthor Service Mesh provide consoles where they can be examined:

• Golden Signals: such as request rate, errors, latencies and resources used (CPU, memory, disk).
• Topology graphs: to visualize where services are deployed and how they interconnect.
• Metrics: detailed, showing requests per second, errors and latencies.

By looking at these metrics, developers can make critical scalability adjustments and ensure that the system operates efficiently even in the face of peak demand.

It is fascinating to see how these tools enable fine-grained control and facilitate large-scale management, providing greater security and operational efficiency. The invitation is to continue exploring and experimenting to take full advantage of the infrastructure that Kubernetes and its related tools offer.