k8s_patch.sh

#!/bin/bash

# dnsConfig
kubectl -n kafka patch deployments kafka-0 -p '{"spec":{"template":{"spec":{"dnsConfig":{"options":[{"name":"single-request-reopen"}]}}}}}'

# dnsOptions
kubectl patch deploy $name \
  -p '{"spec":{"template":{"spec":{"dnsConfig":{"options":[{"name":"single-request-reopen"}]}}}}}'

function t(){
    local ns deploy
    for ns in $@;do
      for deploy in $(kubectl -n $ns   get deploy --no-headers  | awk '{print $1}');do
        kubectl -n $ns patch deploy $deploy  \
            -p '{"spec":{"template":{"spec":{"dnsConfig":{"options":[{"name":"single-request-reopen"}]}}}}}'
      done
    done
}

# hostNetwork
kubectl -n ingress-nginx \
  patch deploy nginx-ingress-controller \
  -p '{"spec":{"template":{"spec":{"dnsPolicy":"ClusterFirstWithHostNet","hostNetwork":true}}}}'

# patch deploy imagePullPolicy
kubectl patch deploy $name \
  -p '{"spec":{"template":{"spec":{"containers": ['$(
    kubectl get deploy $name  -o jsonpath='{range .spec.template.spec.containers[*]}{"{\"name\":\""}{.name}{"\",\"imagePullPolicy\":\"IfNotPresent\"}\n"}{end}' | paste -s - -d ,
  )'] }}}}'

# patch all deploy imagePullPolicy
while read name;do
kubectl patch deploy $name \
  -p '{"spec":{"template":{"spec":{"containers": ['$(
    kubectl get deploy $name  -o jsonpath='{range .spec.template.spec.containers[*]}{"{\"name\":\""}{.name}{"\",\"imagePullPolicy\":\"IfNotPresent\"}\n"}{end}' | paste -s - -d ,
  )'] }}}}'
done< <(kubectl get deployments --no-headers | awk '{print $1}')


while read ns name;do
  kubectl -n $ns patch deployments $name \
      -p '{"spec":{"template":{"spec":{"imagePullSecrets":[{"name":"regcred"}]}}}}'
done< <(kubectl get deployments --no-headers --all-namespaces | awk '{print $1,$2}')


kubectl patch deployments ng-test --type=json -p='[{"op":"replace","path":"/spec/template/spec/affinity/podAntiAffinity","value": {
              "preferredDuringSchedulingIgnoredDuringExecution": [{
                  "weight": 100,
                  "podAffinityTerm":{
                    "labelSelector": {
                        "matchExpressions": [
                            {
                                "key": "app",
                                "operator": "In",
                                "values": [
                                    "ng-test"
                                ]
                            }
                        ]
                    },
                    "topologyKey": "kubernetes.io/hostname"
                  }
              }]
          }}]'

kubectl patch deployments test --type=json -p='[{"op":"replace","path":"/spec/template/spec/affinity","value": {
          "podAntiAffinity": {
              "preferredDuringSchedulingIgnoredDuringExecution": [{
                  "weight": 100,
                  "podAffinityTerm":{
                    "labelSelector": {
                        "matchExpressions": [
                            {
                                "key": "app",
                                "operator": "In",
                                "values": [
                                    "test"
                                ]
                            }
                        ]
                    },
                    "topologyKey": "kubernetes.io/hostname"
                  }
              }]
          }
  }
}]'

kubectl patch deployment x -p '{"op": "add", "path": "/spec/template/spec/containers/0/ports/-", "value": {"containerPort": 80, "hostPort":81,"protocol": "TCP"}}'