How to exclude HA backup pod from node group selector in kubernates?

I want to create nodegroup selector which contain only primary pod and exclude backup pod in kubernates. How to achieve that using helm chart ?

appVersion: version1
kind: StatefulSet
metadata: 
  name: statefulname
  label: 
    ....
    ....
    ....
spec:
  replica: 2

  .....
 container:
   .....
   ....
   nodeselecor:
    {{$nodegroup}}

here result is

 NAME                    READY   STATUS    STARTS   AGE
pod/zookeeper-np-0       1/1     Running   0        203s
pod/zookeeper-np-1       1/1     Running   0        137s

here replica create 2 instance of pod with suffix -0 and -1 and both have same node selector but i want to that for pod/zookeeper-np-0 for this node selector is node group ng1 pod/zookeeper-np-1 for this node selector is node group ng2

i tried with iterate also not getting error

Caused By: java.lang.IllegalStateException: Identified another participant with the same name for Space: newspace_container_newspace

Solution

You have not shared the K8s version details however you can look for the using the Node affinity with statefulset or else topologySpreadConstraints

topologySpreadConstraints:
    - maxSkew: <integer>
      topologyKey: <string>
      whenUnsatisfiable: <string>
      labelSelector: <object>

using the topologySpreadConstraints you can spread the PODs across the nodes.

Node Affinity

nodeAffinity:
      requiredDuringSchedulingIgnoredDuringExecution:
        nodeSelectorTerms:
        - matchExpressions:
          - key: kubernetes.io/e2e-az-name
            operator: In
            values:
            - e2e-az1
            - e2e-az2

You can also use the node affinity to do the same scheduling the PODs on different nodes.