// EnvVarSource represents a source for the value of an EnvVar.
type EnvVarSource struct {
// Selects a field of the pod: supports metadata.name, metadata.namespace, `metadata.labels['<KEY>']`, `metadata.annotations['<KEY>']`,
// spec.nodeName, spec.serviceAccountName, status.hostIP, status.podIP, status.podIPs.
// +optional
FieldRef *ObjectFieldSelector `json:"fieldRef,omitempty" protobuf:"bytes,1,opt,name=fieldRef"`
// Selects a resource of the container: only resources limits and requests
// (limits.cpu, limits.memory, limits.ephemeral-storage, requests.cpu, requests.memory and requests.ephemeral-storage) are currently supported.
// +optional
ResourceFieldRef *ResourceFieldSelector `json:"resourceFieldRef,omitempty" protobuf:"bytes,2,opt,name=resourceFieldRef"`
// Selects a key of a ConfigMap.
// +optional
ConfigMapKeyRef *ConfigMapKeySelector `json:"configMapKeyRef,omitempty" protobuf:"bytes,3,opt,name=configMapKeyRef"`
// Selects a key of a secret in the pod's namespace
// +optional
SecretKeyRef *SecretKeySelector `json:"secretKeyRef,omitempty" protobuf:"bytes,4,opt,name=secretKeyRef"`
}
k8s api :