06 Others

So all should have spec and status? Not necessarily. There are plenty of examples in the kubernetes repository to show otherwise:

ConfigMap

Original Source

// ConfigMap holds configuration data for pods to consume.
type ConfigMap struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// Data contains the configuration data.
	// Each key must consist of alphanumeric characters, '-', '_' or '.'.
	// Values with non-UTF-8 byte sequences must use the BinaryData field.
	// The keys stored in Data must not overlap with the keys in
	// the BinaryData field, this is enforced during validation process.
	// +optional
	Data map[string]string `json:"data,omitempty" protobuf:"bytes,2,rep,name=data"`

	// BinaryData contains the binary data.
	// Each key must consist of alphanumeric characters, '-', '_' or '.'.
	// BinaryData can contain byte sequences that are not in the UTF-8 range.
	// The keys stored in BinaryData must not overlap with the ones in
	// the Data field, this is enforced during validation process.
	// Using this field will require 1.10+ apiserver and
	// kubelet.
	// +optional
	BinaryData map[string][]byte `json:"binaryData,omitempty" protobuf:"bytes,3,rep,name=binaryData"`
}

ServiceAccount

Original Source

// ServiceAccount binds together:
// * a name, understood by users, and perhaps by peripheral systems, for an identity
// * a principal that can be authenticated and authorized
// * a set of secrets
type ServiceAccount struct {
	metav1.TypeMeta `json:",inline"`
	// Standard object's metadata.
	// More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata
	// +optional
	metav1.ObjectMeta `json:"metadata,omitempty" protobuf:"bytes,1,opt,name=metadata"`

	// Secrets is the list of secrets allowed to be used by pods running using this ServiceAccount.
	// More info: https://kubernetes.io/docs/concepts/configuration/secret
	// +optional
	// +patchMergeKey=name
	// +patchStrategy=merge
	Secrets []ObjectReference `json:"secrets,omitempty" patchStrategy:"merge" patchMergeKey:"name" protobuf:"bytes,2,rep,name=secrets"`

	// ImagePullSecrets is a list of references to secrets in the same namespace to use for pulling any images
	// in pods that reference this ServiceAccount. ImagePullSecrets are distinct from Secrets because Secrets
	// can be mounted in the pod, but ImagePullSecrets are only accessed by the kubelet.
	// More info: https://kubernetes.io/docs/concepts/containers/images/#specifying-imagepullsecrets-on-a-pod
	// +optional
	ImagePullSecrets []LocalObjectReference `json:"imagePullSecrets,omitempty" protobuf:"bytes,3,rep,name=imagePullSecrets"`

	// AutomountServiceAccountToken indicates whether pods running as this service account should have an API token automatically mounted.
	// Can be overridden at the pod level.
	// +optional
	AutomountServiceAccountToken *bool `json:"automountServiceAccountToken,omitempty" protobuf:"varint,4,opt,name=automountServiceAccountToken"`
}

Summary

Resources that does not have a process or a state can be represented using multiple properties instead of nesting inside a spec. This simplifies usage and understanding.