Implement deletion order.

api/v1alpha1/githubactionrunner_types.go

@@ -41,8 +41,24 @@ type GithubActionRunnerSpec struct {
 	// +kubebuilder:validation:Optional
 	// +kubebuilder:default="1m"
 	ReconciliationPeriod string `json:"reconciliationPeriod"`
+
+	// What order to delete idle pods in
+	// +kubebuilder:default="LeastRecent"
+	// +kubebuilder:validation:Optional
+	DeletionOrder SortOrder `json:"deletionOrder"`
 }
 
+const (
+	// LeastRecent first.
+	LeastRecent SortOrder = "LeastRecent"
+	// MostRecent first.
+	MostRecent  SortOrder = "MostRecent"
+)
+
+// SortOrder defines order to sort by when sorting on creation timestamp.
+// +kubebuilder:validation:Enum=MostRecent;LeastRecent
+type SortOrder string
+
 // IsValid validates conditions not covered by basic OpenAPI constraints
 func (r GithubActionRunnerSpec) IsValid() (bool, error) {
 	if r.MaxRunners < r.MinRunners {

config/crd/bases/garo.tietoevry.com_githubactionrunners.yaml

@@ -43,6 +43,13 @@ spec:
           spec:
             description: GithubActionRunnerSpec defines the desired state of GithubActionRunner
             properties:
+              deletionOrder:
+                default: LeastRecent
+                description: What order to delete idle pods in
+                enum:
+                - MostRecent
+                - LeastRecent
+                type: string
               maxRunners:
                 description: Maximum pool-size. Must be greater or equal to minRunners
                 minimum: 1

controllers/githubactionrunner_controller.go

@@ -135,7 +135,7 @@ func (r *GithubActionRunnerReconciler) handleScaling(ctx context.Context, instan
 	} else if shouldScaleDown(podRunnerPairs, instance) {
 		logger.Info("Scaling down", "runners at github", podRunnerPairs.numRunners(), "maxrunners in CR", instance.Spec.MaxRunners)
 
-		pod := podRunnerPairs.getIdlePods()[0]
+		pod := podRunnerPairs.getIdlePods(instance.Spec.DeletionOrder)[0]
 		err := r.DeleteResourceIfExists(ctx, &pod)
 		if err == nil {
 			r.GetRecorder().Event(instance, corev1.EventTypeNormal, "Scaling", fmt.Sprintf("Deleted pod %s/%s", pod.Namespace, pod.Name))

controllers/podrunner_types.go

@@ -1,10 +1,12 @@
 package controllers
 
 import (
+	"github.com/evryfs/github-actions-runner-operator/api/v1alpha1"
 	"github.com/google/go-github/v33/github"
 	"github.com/redhat-cop/operator-utils/pkg/util"
 	"github.com/thoas/go-funk"
 	corev1 "k8s.io/api/core/v1"
+	"sort"
 )
 
 type podRunnerPair struct {
@@ -66,13 +68,22 @@ func (r podRunnerPairList) inSync() bool {
 	return r.numPods() == r.numRunners()
 }
 
-func (r podRunnerPairList) getIdlePods() []corev1.Pod {
+func (r podRunnerPairList) getIdlePods(sortOrder v1alpha1.SortOrder) []corev1.Pod {
 	idles := funk.Filter(r.pairs, func(pair podRunnerPair) bool {
 		return !(pair.runner.GetBusy() || util.IsBeingDeleted(&pair.pod))
 	}).([]podRunnerPair)
-	return funk.Map(idles, func(pair podRunnerPair) corev1.Pod {
+	pods := funk.Map(idles, func(pair podRunnerPair) corev1.Pod {
 		return pair.pod
 	}).([]corev1.Pod)
+
+	sort.SliceStable(pods, func(i, j int) bool {
+		if sortOrder == v1alpha1.LeastRecent {
+			return pods[i].CreationTimestamp.Unix() < pods[j].CreationTimestamp.Unix()
+		}
+		return pods[i].CreationTimestamp.Unix() > pods[j].CreationTimestamp.Unix()
+	})
+
+	return pods
 }
 
 func (r podRunnerPairList) getPodsBeingDeleted() []podRunnerPair {

controllers/podrunner_types_test.go

@@ -1,12 +1,14 @@
 package controllers
 
 import (
+	"github.com/evryfs/github-actions-runner-operator/api/v1alpha1"
 	"github.com/google/go-github/v33/github"
 	"github.com/stretchr/testify/assert"
 	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/utils/pointer"
 	"testing"
+	"time"
 )
 
 var podList = v1.PodList{
@@ -16,15 +18,17 @@ var podList = v1.PodList{
 		{
 			TypeMeta: metav1.TypeMeta{},
 			ObjectMeta: metav1.ObjectMeta{
-				Name: "name1",
+				Name:              "name1",
+				CreationTimestamp: metav1.NewTime(time.Now()),
 			},
 			Spec:   v1.PodSpec{},
 			Status: v1.PodStatus{},
 		},
 		{
 			TypeMeta: metav1.TypeMeta{},
 			ObjectMeta: metav1.ObjectMeta{
-				Name: "name2",
+				Name:              "name2",
+				CreationTimestamp: metav1.NewTime(time.Now().Add(time.Minute)),
 			},
 			Spec:   v1.PodSpec{},
 			Status: v1.PodStatus{},
@@ -67,3 +71,19 @@ func TestPodRunnerPairList(t *testing.T) {
 		assert.Equal(t, podRunnerPairList.inSync(), tc.inSync)
 	}
 }
+
+func TestSort(t *testing.T) {
+	testCases := []struct {
+		sortOrder         v1alpha1.SortOrder
+		podRunnerPairList podRunnerPairList
+		podList           []v1.Pod
+	}{
+		{v1alpha1.LeastRecent, from(&podList, runners), []v1.Pod{podList.Items[0], podList.Items[1]}},
+		{v1alpha1.MostRecent, from(&podList, runners), []v1.Pod{podList.Items[1], podList.Items[0]}},
+	}
+
+	for _, tc := range testCases {
+		podList := tc.podRunnerPairList.getIdlePods(tc.sortOrder)
+		assert.Equal(t, podList, tc.podList)
+	}
+}