From 6c826a9dede8f28cf960a0f99a78941caa6facb9 Mon Sep 17 00:00:00 2001
From: Joseph Salisbury <salisbury.joseph@gmail.com>
Date: Fri, 14 Jun 2024 16:04:42 +0100
Subject: [PATCH] Adds test cases for control plane pod requests

---
 internal/common/common.go   |  1 +
 internal/common/requests.go | 81 +++++++++++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+)
 create mode 100644 internal/common/requests.go

diff --git a/internal/common/common.go b/internal/common/common.go
index ce60e8b3..94a8f0f8 100644
--- a/internal/common/common.go
+++ b/internal/common/common.go
@@ -18,4 +18,5 @@ func Run(cfg *TestConfig) {
 	runHelloWorld(cfg.ExternalDnsSupported)
 	runScale(cfg.AutoScalingSupported)
 	runStorage()
+	runRequests()
 }
diff --git a/internal/common/requests.go b/internal/common/requests.go
new file mode 100644
index 00000000..f4e16977
--- /dev/null
+++ b/internal/common/requests.go
@@ -0,0 +1,81 @@
+package common
+
+import (
+	"context"
+	"time"
+
+	"github.com/giantswarm/cluster-test-suites/internal/state"
+	"github.com/giantswarm/clustertest/pkg/client"
+	"github.com/giantswarm/clustertest/pkg/wait"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/api/resource"
+	cr "sigs.k8s.io/controller-runtime/pkg/client"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+const (
+	MaximumCPURequestUtilization    float64 = 0.8
+	MaximumMemoryRequestUtilization float64 = 0.8
+)
+
+func runRequests() {
+	Context("requests", func() {
+		var wcClient *client.Client
+
+		BeforeEach(func() {
+			var err error
+
+			wcClient, err = state.GetFramework().WC(state.GetCluster().Name)
+			if err != nil {
+				Fail(err.Error())
+			}
+		})
+
+		It("has spare CPU request capacity on the control plane nodes", func() {
+			Eventually(checkControlPlaneNodesHaveSpareRequestCapacity(wcClient, corev1.ResourceCPU, MaximumCPURequestUtilization)).
+				WithTimeout(15 * time.Minute).
+				WithPolling(wait.DefaultInterval).
+				Should(BeTrue())
+		})
+
+		It("has spare memory request capacity on the control plane nodes", func() {
+			Eventually(checkControlPlaneNodesHaveSpareRequestCapacity(wcClient, corev1.ResourceMemory, MaximumMemoryRequestUtilization)).
+				WithTimeout(15 * time.Minute).
+				WithPolling(wait.DefaultInterval).
+				Should(BeTrue())
+		})
+	})
+}
+
+func checkControlPlaneNodesHaveSpareRequestCapacity(wcClient *client.Client, resourceName corev1.ResourceName, utilization float64) wait.WaitCondition {
+	return func() (bool, error) {
+		totalRequested := resource.NewQuantity(0, resource.DecimalSI)
+		totalAllocatable := resource.NewQuantity(0, resource.DecimalSI)
+
+		nodes := &corev1.NodeList{}
+		err := wcClient.List(context.Background(), nodes, &cr.MatchingLabels{"node-role.kubernetes.io/control-plane": ""})
+		if err != nil {
+			return false, err
+		}
+
+		for _, node := range nodes.Items {
+			pods := &corev1.PodList{}
+			err := wcClient.List(context.Background(), pods, &cr.MatchingFields{"spec.nodeName": node.Name})
+			if err != nil {
+				return false, err
+			}
+
+			for _, pod := range pods.Items {
+				for _, container := range pod.Spec.Containers {
+					totalRequested.Add(container.Resources.Requests[resourceName])
+				}
+			}
+
+			totalAllocatable.Add(node.Status.Allocatable[resourceName])
+		}
+
+		return totalRequested.AsApproximateFloat64() < totalAllocatable.AsApproximateFloat64()*utilization, nil
+	}
+}