eck：Elasticsearch running in k8s use Kubernetes operator-优快云博客

本文档详细介绍了如何在Kubernetes集群中部署和卸载Elastic Cloud on Kubernetes (ECK)。安装过程包括创建CustomResourceDefinition对象、设置资源限制、安装Operator及其RBAC规则，并提供了监控Operator日志的方法。卸载过程涉及删除所有Elastic资源和Operator组件。

https://www.elastic.co/guide/en/cloud-on-k8s/2.1/index.html

The value set for cpu requests directly impacts Elasticsearch node.processors setting. For example, with resources.requests.cpu: 1,

Elasticsearch effectively relies on a single core

Table 1. Default limits applied by the operator

Type	Requests	Limits
APM Server	`512Mi`	`512Mi`
Elasticsearch	`2Gi`	`2Gi`
Kibana	`1Gi`	`1Gi`
Beat	`200Mi`	`200Mi`
Elastic Agent	`350Mi`	`350Mi`
Elastic Maps Sever	`200Mi`	`200Mi`
Enterprise Search	`4Gi`	`4Gi`

安装：

三步，装crd，装operator，查看log

Install custom resource definitions:

kubectl create -f https://download.elastic.co/downloads/eck/2.1.0/crds.yaml

The following Elastic resources have been created:

customresourcedefinition.apiextensions.k8s.io/agents.agent.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/apmservers.apm.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/beats.beat.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/elasticmapsservers.maps.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/elasticsearches.elasticsearch.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/enterprisesearches.enterprisesearch.k8s.elastic.co created customresourcedefinition.apiextensions.k8s.io/kibanas.kibana.k8s.elastic.co created

Install the operator with its RBAC rules:
```
kubectl apply -f https://download.elastic.co/downloads/eck/2.1.0/operator.yaml
```
The ECK operator runs by default in the elastic-system namespace. It is recommended that you choose a dedicated namespace for your workloads, rather than using the elastic-system or the default namespace.

Monitor the operator logs:

kubectl -n elastic-system logs -f statefulset.apps/elastic-operator

安装干了下边这些事：

When you run the kubectl command listed in Deploy ECK in your Kubernetes cluster, the following components are installed or updated:

CustomResourceDefinition objects for all supported resource types (Elasticsearch, Kibana, APM Server, Enterprise Search, Beats, Elastic Agent, and Elastic Maps Server).
Namespace named elastic-system to hold all operator resources.
ServiceAccount, ClusterRole and ClusterRoleBinding to allow the operator to manage resources throughout the cluster.
ValidatingWebhookConfiguration to validate Elastic custom resources on admission.
StatefulSet, ConfigMap, Secret and Service in elastic-system namespace to run the operator application.

卸载：

To uninstall the operator:

Remove all Elastic resources in all namespaces:
```
kubectl get namespaces --no-headers -o custom-columns=:metadata.name \ | xargs -n1 kubectl delete elastic --all -n
```
This deletes all underlying Elastic Stack resources, included their Pods, Secrets, Services, and so on.

Uninstall the operator:

kubectl delete -f https://download.elastic.co/downloads/eck/2.1.0/operator.yaml kubectl delete -f https://download.elastic.co/downloads/eck/2.1.0/crds.yaml