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12. High Availability

KubeVIP

kube-vip provides Kubernetes clusters with a virtual IP and load balancer for both the control plane (for building a highly-available cluster) and Kubernetes Services of type LoadBalancer without relying on any external hardware or software.

Horizontal Pod Autoscaling

HPA

In Kubernetes, a HorizontalPodAutoscaler automatically updates a workload resource (such as a Deployment or StatefulSet), with the aim of automatically scaling the workload to match demand.

Vertical Pod Autoscaler

VPA

Vertical Pod Autoscaler (VPA) frees users from the necessity of setting up-to-date resource limits and requests for the containers in their pods. When configured, it will set the requests automatically based on usage and thus allow proper scheduling onto nodes so that appropriate resource amount is available for each pod. It will also maintain ratios between limits and requests that were specified in initial containers configuration.

Cert Manager

cert-manager creates TLS certificates for workloads in your Kubernetes or OpenShift cluster and renews the certificates before they expire.

Custom Resource Definition

Custom resources are extensions of the Kubernetes API. This page discusses when to add a custom resource to your Kubernetes cluster and when to use a standalone service. It describes the two methods for adding custom resources and how to choose between them.

Ingress via CertManager

How to secure ingress via cert manager

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    # add an annotation indicating the issuer to use.
    cert-manager.io/cluster-issuer: nameOfClusterIssuer
  name: myIngress
  namespace: myIngress
spec:
  rules:
  - host: example.com
    http:
      paths:
      - pathType: Prefix
        path: /
        backend:
          service:
            name: myservice
            port:
              number: 80
  tls: # < placing a host in the TLS config will determine what ends up in the cert's subjectAltNames
  - hosts:
    - example.com
    secretName: myingress-cert # < cert-manager will store the created certificate in this secret.

The tls and annotation field added to ingress