feat: RunnerSets

RunnerSet is basically ReplicaSet for Runners.

It is responsible for maintaining number of runners to match the desired one. That is, it creates missing runners from `.Spec.Template` and deletes redundant runners.

Similar to ReplicaSet, this does not support rolling update of runners on its own. We might want to later add `RunnerDeployment` for that. But that's another story.

api/v1alpha1/runner_types.go

@@ -88,6 +88,42 @@ type RunnerList struct {
 	Items           []Runner `json:"items"`
 }
 
-func init() {
-	SchemeBuilder.Register(&Runner{}, &RunnerList{})
+// +kubebuilder:object:root=true
+// +kubebuilder:subresource:status
+// +kubebuilder:printcolumn:JSONPath=".spec.replicas",name=Desired,type=number
+// +kubebuilder:printcolumn:JSONPath=".status.availableReplicas",name=Current,type=number
+// +kubebuilder:printcolumn:JSONPath=".status.readyReplicas",name=Ready,type=number
+
+// RunnerSet is the Schema for the runnersets API
+type RunnerSet struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   RunnerSetSpec   `json:"spec,omitempty"`
+	Status RunnerSetStatus `json:"status,omitempty"`
+}
+
+// RunnerSetSpec defines the desired state of RunnerSet
+type RunnerSetSpec struct {
+	Replicas *int `json:"replicas"`
+
+	Template RunnerSpec `json:"template"`
+}
+
+type RunnerSetStatus struct {
+	AvailableReplicas int `json:"availableReplicas"`
+	ReadyReplicas     int `json:"readyReplicas"`
+}
+
+// +kubebuilder:object:root=true
+
+// RunnerList contains a list of Runner
+type RunnerSetList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata,omitempty"`
+	Items           []RunnerSet `json:"items"`
+}
+
+func init() {
+	SchemeBuilder.Register(&Runner{}, &RunnerList{}, &RunnerSet{}, &RunnerSetList{})
 }

api/v1alpha1/zz_generated.deepcopy.go

@@ -84,6 +84,101 @@ func (in *RunnerList) DeepCopyObject() runtime.Object {
 	return nil
 }
 
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *RunnerSet) DeepCopyInto(out *RunnerSet) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ObjectMeta.DeepCopyInto(&out.ObjectMeta)
+	in.Spec.DeepCopyInto(&out.Spec)
+	out.Status = in.Status
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSet.
+func (in *RunnerSet) DeepCopy() *RunnerSet {
+	if in == nil {
+		return nil
+	}
+	out := new(RunnerSet)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *RunnerSet) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *RunnerSetList) DeepCopyInto(out *RunnerSetList) {
+	*out = *in
+	out.TypeMeta = in.TypeMeta
+	in.ListMeta.DeepCopyInto(&out.ListMeta)
+	if in.Items != nil {
+		in, out := &in.Items, &out.Items
+		*out = make([]RunnerSet, len(*in))
+		for i := range *in {
+			(*in)[i].DeepCopyInto(&(*out)[i])
+		}
+	}
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSetList.
+func (in *RunnerSetList) DeepCopy() *RunnerSetList {
+	if in == nil {
+		return nil
+	}
+	out := new(RunnerSetList)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyObject is an autogenerated deepcopy function, copying the receiver, creating a new runtime.Object.
+func (in *RunnerSetList) DeepCopyObject() runtime.Object {
+	if c := in.DeepCopy(); c != nil {
+		return c
+	}
+	return nil
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *RunnerSetSpec) DeepCopyInto(out *RunnerSetSpec) {
+	*out = *in
+	if in.Replicas != nil {
+		in, out := &in.Replicas, &out.Replicas
+		*out = new(int)
+		**out = **in
+	}
+	in.Template.DeepCopyInto(&out.Template)
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSetSpec.
+func (in *RunnerSetSpec) DeepCopy() *RunnerSetSpec {
+	if in == nil {
+		return nil
+	}
+	out := new(RunnerSetSpec)
+	in.DeepCopyInto(out)
+	return out
+}
+
+// DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
+func (in *RunnerSetStatus) DeepCopyInto(out *RunnerSetStatus) {
+	*out = *in
+}
+
+// DeepCopy is an autogenerated deepcopy function, copying the receiver, creating a new RunnerSetStatus.
+func (in *RunnerSetStatus) DeepCopy() *RunnerSetStatus {
+	if in == nil {
+		return nil
+	}
+	out := new(RunnerSetStatus)
+	in.DeepCopyInto(out)
+	return out
+}
+
 // DeepCopyInto is an autogenerated deepcopy function, copying the receiver, writing into out. in must be non-nil.
 func (in *RunnerSpec) DeepCopyInto(out *RunnerSpec) {
 	*out = *in