En este capítulo hablamos de cómo se comunican los pods dentro del clúster, cómo se descubren las aplicaciones entre sí y cómo exponer los pods para que se pueda acceder a ellos desde fuera del clúster.
El recurso que utilizaremos aquí se llama servicio Kubernetes, como se muestra en la Figura 5-1.
Figura 5-1. El concepto de servicio Kubernetes
Un servicio proporciona una dirección IP virtual (VIP) estable para un conjunto de pods. Aunque los pods pueden ir y venir, los servicios permiten a los clientes descubrir y conectarse de forma fiable a los contenedores que se ejecutan en los pods utilizando la VIP. El "virtual" en VIP significa que no es una dirección IP real conectada a una interfaz de red; su propósito es puramente reenviar tráfico a uno o más pods. Mantener actualizado el mapeo entre los VIPs y los pods es tarea de kube-proxy, un proceso que se ejecuta en cada nodo del clúster. Este proceso de kube-proxy consulta al servidor API para conocer los nuevos servicios del clúster y actualiza en consecuencia las reglas iptables (iptables) del nodo para proporcionar la información de enrutamiento necesaria.
5.1 Crear un servicio para exponer tu aplicación
Problema
Quieres proporcionar una forma estable y fiable de descubrir ...
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