fix: Device Plugin daemonset keep restarting

Define an ordering of the NodeSelectorRequirement in the daemonset to
avoid the daemonset to be unstable when policies come in different
order.

Fixes #804

Author: armandpicard

controllers/helper.go

@@ -311,6 +311,27 @@ func nodeSelectorTermsForPolicyList(policies []sriovnetworkv1.SriovNetworkNodePo
 		terms = append(terms, nodeSelector)
 	}
 
+	// sorting is needed to keep the daemon spec stable.
+	// the policies can come in a random order
+	sort.Slice(terms, func(i, j int) bool {
+		expressionsA := terms[i].MatchExpressions
+		expressionsB := terms[j].MatchExpressions
+		if len(expressionsA) != len(expressionsB) {
+			return len(expressionsA) < len(expressionsB)
+		}
+		for k := range expressionsA {
+			expressionA := expressionsA[k]
+			expressionB := expressionsB[k]
+			if expressionA.Key != expressionB.Key {
+				return expressionA.Key < expressionB.Key
+			}
+			if expressionA.Values[0] != expressionB.Values[0] {
+				return expressionA.Values[0] != expressionB.Values[0]
+			}
+		}
+		return true
+	})
+
 	return terms
 }
 

controllers/helper_test.go

@@ -64,17 +64,17 @@ func TestNodeSelectorMerge(t *testing.T) {
 					MatchExpressions: []corev1.NodeSelectorRequirement{
 						{
 							Operator: corev1.NodeSelectorOpIn,
-							Key:      "foo",
-							Values:   []string{"bar"},
+							Key:      "bb",
+							Values:   []string{"cc"},
 						},
 					},
 				},
 				{
 					MatchExpressions: []corev1.NodeSelectorRequirement{
 						{
 							Operator: corev1.NodeSelectorOpIn,
-							Key:      "bb",
-							Values:   []string{"cc"},
+							Key:      "foo",
+							Values:   []string{"bar"},
 						},
 					},
 				},