CLD-478: Default affinity code changes commit

Co-authored-by: Sumanth Ravipati <[email protected]>

Author: sumanthravipati

charts/values.yaml

@@ -55,7 +55,19 @@ auth:
 
 # Configure Affinity property for scheduling pods to nodes
 # ref: https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#affinity-and-anti-affinity
-affinity: {}
+# Preferred anti affinity rule to schedule one marklogic pod per worker node
+affinity: 
+  podAntiAffinity:
+    preferredDuringSchedulingIgnoredDuringExecution:
+    - weight: 100
+      podAffinityTerm:
+        labelSelector:
+          matchExpressions:
+          - key: app.kubernetes.io/name
+            operator: In
+            values:
+            - marklogic
+        topologyKey: kubernetes.io/hostname
 
 # Configure NodeSelector property for scheduling pods to nodes
 # ref: https://kubernetes.io/docs/tasks/configure-pod-container/assign-pods-nodes/#create-a-pod-that-gets-scheduled-to-your-chosen-node

test/template/pod_antiaffinity_templ_test.go

@@ -0,0 +1,60 @@
+package template_test
+
+import (
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	appsv1 "k8s.io/api/apps/v1"
+
+	"github.com/gruntwork-io/terratest/modules/helm"
+	"github.com/gruntwork-io/terratest/modules/k8s"
+	"github.com/gruntwork-io/terratest/modules/random"
+)
+
+func TestChartTemplatePodAntiAffinityClass(t *testing.T) {
+	t.Parallel()
+
+	// Path to the helm chart we will test
+	helmChartPath, err := filepath.Abs("../../charts")
+	releaseName := "marklogic-pod-antiaffinity-test"
+	t.Log(helmChartPath, releaseName)
+	require.NoError(t, err)
+
+	// Set up the namespace; confirm that the template renders the expected value for the namespace.
+	namespaceName := "marklogic-" + strings.ToLower(random.UniqueId())
+	t.Logf("Namespace: %s\n", namespaceName)
+
+	// Setup the args for helm install
+	options := &helm.Options{
+		SetValues: map[string]string{
+			"image.repository":    "marklogicdb/marklogic-db",
+			"image.tag":           "latest",
+			"persistence.enabled": "false",
+		},
+		KubectlOptions: k8s.NewKubectlOptions("", "", namespaceName),
+	}
+
+	// render the tempate
+	output := helm.RenderTemplate(t, options, helmChartPath, releaseName, []string{"templates/statefulset.yaml"})
+
+	var statefulset appsv1.StatefulSet
+	helm.UnmarshalK8SYaml(t, output, &statefulset)
+
+	// Verify the name and namespace matches
+	require.Equal(t, namespaceName, statefulset.Namespace)
+
+	// Verify the pod anti affinity rule is set
+	expectedLabelSelectorKey := "app.kubernetes.io/name"
+	expectedLabelSelectorValue := "marklogic"
+	expectedTopologyKey := "kubernetes.io/hostname"
+	statefulSetAffinityRule := statefulset.Spec.Template.Spec.Affinity.PodAntiAffinity
+	affinityPreferredRule := statefulSetAffinityRule.PreferredDuringSchedulingIgnoredDuringExecution
+	actualLabelSelectorKey := affinityPreferredRule[0].PodAffinityTerm.LabelSelector.MatchExpressions[0].Key
+	actualLabelSelectorValue := affinityPreferredRule[0].PodAffinityTerm.LabelSelector.MatchExpressions[0].Values[0]
+	actualTopologyKey := affinityPreferredRule[0].PodAffinityTerm.TopologyKey
+	require.Equal(t, actualLabelSelectorKey, expectedLabelSelectorKey)
+	require.Equal(t, actualLabelSelectorValue, expectedLabelSelectorValue)
+	require.Equal(t, actualTopologyKey, expectedTopologyKey)
+}