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Operator Custom Resource Reference Guide

Custom resources are extensions of the Kubernetes API.

A resource is an endpoint in the Kubernetes API that stores a collection of API objects of a certain kind; for example, the built-in pods resource contains a collection of Pod objects. A Custom Resource is an extension of the Kubernetes API, many core Kubernetes functions are now built using custom resources, making Kubernetes more modular. Cluster admins can update custom resources independently of the cluster itself. Once a custom resource is installed, users can create and access its objects using kubectl, just as they do for built-in resources like Pods.

The CustomResourceDefinition API resource allows you to define custom resources. Defining a CRD object creates a new custom resource with a name and schema that you specify. The Kubernetes API serves and handles the storage of your custom resource. Every resource is build from KGV that stands for Group Version Resource and this is what drives the Kubernetes API Server structure. The OpensearchCLuster CRD is representing an Opensearch cluster.

Our CRD is Defined by kind: OpenSearchCluster,group: opensearch.opster.io and version v1.

Name	Type	Description	Required
apiVersion	string	opensearch.opster.io/v1	true
kind	string	OpenSearchCluster	true
metadata	object	Refer to the Kubernetes API documentation for the fields of the `metadata` field.	true
spec	object	ClusterSpec defines the desired state of OpenSearchSpec	true
status	object	OpensearchClusterStatus defines the observed state of ClusterStatus. include ComponentsStatus that saves and share necessary state of the operator components.	true

OpensearchCluster.spec

ClusterSpec defines the desired state of OpensearchCluster

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GeneralConfig

GeneralConfig defines global Opensearch cluster configuration

Name	Type	Description	Required
general	object	Opensearch general configuration	true
Dashboards	object	Opensearch-dashboards configuration	false
confMgmt	object	Config object to enable additional OpensearchOperator features/components	false
security	object	Defined security reconciler configuration	false
nodePools	[]object	List of objects that define the different nodePools in an OpensearchCluster. Each nodePool represents a group of nodes with the same opensearch roles and resources. Each nodePool is deployed as a Kubernetes StatefulSet. Together they form the opensearch cluster.	true

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Dashboards

Dashboards defines Opensearch-Dashboard configuration and deployment

Name	Type	Description	Required	default
httpPort	int32	http exposure port	false	9200
vendor	string	Vendor distribution to use for the cluster, currently only opensearch is supported	false	opensearch
version	string	Version of opensearch to deploy	false	latest
ServiceAccount	string	k8s service account name	false	cluster name
ServiceName	string	Name to use for the k8s service to expose the cluster internally	false	cluster name
SetVMMaxMapCount	bool	will add VMmaxMapCount	false
additionalConfig	string	Added extra items to opensearch.yml	string

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NodePools

Every NodePool is defining different Opensearch Nodes StatefulSet

Name	Type	Description	Required	default
enable	bool	if true, will deploy Opensearch-dashboards with the cluster	false	false
replicas	int	defines Opensearch-Dashboards deployment's replicas	true	1
resources	corev1.ResourceRequirements	Define Opensearch-Dashboard resources	false	Default Opensearch-dashboard resources
version	string	Opensearch-dashboards version	false	latest
Tls	DashboardsTlsConfig	defining Dashbaord TLS configuration	false	false

</table>

Name	Type	Description	Required	default
component	string	statefulset name - will create $cluster-name-$component STS	true	-
replicas	int	defines NodePool deployment's replicas	true	1
diskSize	string	nodePool data disk size	true	-
NodeSelector	map[string]string	add NodeSelector to nodePool	false	-
Tls	DashboardsTlsConfig	defining Dashbaord TLS configuration	false	false
resources	corev1.ResourceRequirements	Define NodePool resources	false
roles	[]string	List of OpenSearch roles to assign to the nodePool	true	-
JVM	string	JVM args. Use this to define heap size (recommendation: Set to half of memory request)	false	-Xmx512M -Xms512M
Affinity	corev1.Affinity	add affinity to nodePool	false	-
Tolerations	[]corev1.Toleration	add toleration to nodePool	false	-

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