### Immutable Secrets and ConfigMaps (beta)

Secret and ConfigMap volumes can be marked as immutable, which significantly reduces load on the API server if there are many Secret and ConfigMap volumes in the cluster.
See [ConfigMap](https://kubernetes.io/docs/concepts/configuration/configmap/) and [Secret](https://kubernetes.io/docs/concepts/configuration/secret/) for more information.

          {{- if eq .Values.global.pilotCertProvider "istiod" }}
          - name: istiod-ca-cert
            configMap:
              name: istio-ca-root-cert
          {{- end }}
          {{- if eq .Values.global.pilotCertProvider "kubernetes" }}
          - name: kube-ca-cert
            configMap:
              name: kube-root-ca.crt
          {{- end }}
          {{- if .Values.global.mountMtlsCerts }}

          "optional": {
            "description": "optional specify whether the ConfigMap or its keys must be defined",
            "type": "boolean"
          }
        },
        "type": "object"
      },
      "io.k8s.api.core.v1.ConfigMapVolumeSource": {

		name   string
		newCfg core.ConfigMap
		oldCfg core.ConfigMap
		valid  bool
	}{{
		name:   "valid",
		newCfg: configMap,
		oldCfg: configMap,
		valid:  true,
	}, {
		name:   "invalid",
		newCfg: noVersion,
		oldCfg: configMap,
		valid:  false,
	}, {
		name:   "mark configmap immutable",
		oldCfg: configMap,
		newCfg: immutableConfigMap,

                      A single CACertificateRef to a Kubernetes ConfigMap kind has "Core" support.
                      Implementations MAY choose to support attaching multiple certificates to
                      a backend, but this behavior is implementation-specific.


                      Support: Core - An optional single reference to a Kubernetes ConfigMap,
                      with the CA certificate in a key named `ca.crt`.

          },
          "kind": {
            "default": "",
            "description": "Kind is the type of resource being referenced. This is the same value as in the parameter object's metadata, for example \"ConfigMap\".",
            "type": "string"
          },
          "name": {
            "default": "",
            "description": "Name is the name of resource being referenced.",
            "type": "string"