[Bugfix] Fix node affinity

CHANGELOG.md

@@ -4,6 +4,7 @@
 - Add Labels and Annotations to ServiceMonitor
 - Allow to expose Exporter in HTTP with secured Deployments
 - Change rotation by annotation order (coordinator before dbserver)
+- Fix NodeAffinity propagation
 
 ## [1.0.4](https://github.com/arangodb/kube-arangodb/tree/1.0.4) (2020-07-28)
 - Add Encryption Key rotation feature for ArangoDB EE 3.7+

pkg/deployment/deployment_affinity_test.go

@@ -673,14 +673,15 @@ func TestEnsurePod_ArangoDB_NodeAffinity(t *testing.T) {
 					Subdomain: testDeploymentName + "-int",
 					Affinity: modifyAffinity(testDeploymentName, api.ServerGroupDBServersString,
 						false, "", func(a *core.Affinity) {
-							n := core.NodeSelectorTerm{
-								MatchFields: []core.NodeSelectorRequirement{
-									{
-										Key: "key",
-									},
+							f := a.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms[0]
+
+							f.MatchFields = []core.NodeSelectorRequirement{
+								{
+									Key: "key",
 								},
 							}
-							a.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms = append(a.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms, n)
+
+							a.NodeAffinity.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms[0] = f
 						}),
 				},
 			},

pkg/deployment/pod/affinity.go

@@ -124,15 +124,28 @@ func MergeNodeAffinity(a, b *core.NodeAffinity) {
 		a.PreferredDuringSchedulingIgnoredDuringExecution = append(a.PreferredDuringSchedulingIgnoredDuringExecution, rule)
 	}
 
-	if b.RequiredDuringSchedulingIgnoredDuringExecution != nil {
-		if a.RequiredDuringSchedulingIgnoredDuringExecution == nil {
-			a.RequiredDuringSchedulingIgnoredDuringExecution = b.RequiredDuringSchedulingIgnoredDuringExecution.DeepCopy()
-		} else {
-			for _, rule := range b.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
-				a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms = append(a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms, rule)
+	var newSelectorTerms []core.NodeSelectorTerm
+
+	if b.RequiredDuringSchedulingIgnoredDuringExecution == nil || len(b.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms) == 0 {
+		newSelectorTerms = a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms
+	} else if a.RequiredDuringSchedulingIgnoredDuringExecution == nil || len(a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms) == 0 {
+		newSelectorTerms = b.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms
+	} else {
+		for _, aTerms := range a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
+			for _, bTerms := range b.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms {
+				term := aTerms.DeepCopy()
+				if len(bTerms.MatchExpressions) != 0 {
+					term.MatchExpressions = append(term.MatchExpressions, bTerms.MatchExpressions...)
+				}
+				if len(bTerms.MatchFields) != 0 {
+					term.MatchFields = append(term.MatchFields, bTerms.MatchFields...)
+				}
+				newSelectorTerms = append(newSelectorTerms, *term)
 			}
 		}
 	}
+
+	a.RequiredDuringSchedulingIgnoredDuringExecution.NodeSelectorTerms = newSelectorTerms
 }
 
 func ReturnPodAffinityOrNil(a core.PodAffinity) *core.PodAffinity {