refactor: Fix staticcheck QF* issues

.golangci.yml

@@ -118,7 +118,8 @@ linters:
       # https://staticcheck.dev/docs/configuration/options/#checks
       checks:
       - all
-      - -QF*
+      - -QF1001  # apply De Morgan's law
+      - -QF1008  # remove embedded field from selector
       - -SA3000  # false positive for Go 1.15+. See https://github.com/golang/go/issues/34129
       - -ST1000
       - -ST1001  # duplicates revive.dot-imports

pkg/guestagent/kubernetesservice/kubernetesservice.go

@@ -140,9 +140,10 @@ func (s *ServiceWatcher) GetPorts() []Entry {
 			}
 
 			var port int32
-			if service.Spec.Type == corev1.ServiceTypeNodePort {
+			switch service.Spec.Type {
+			case corev1.ServiceTypeNodePort:
 				port = portEntry.NodePort
-			} else if service.Spec.Type == corev1.ServiceTypeLoadBalancer {
+			case corev1.ServiceTypeLoadBalancer:
 				port = portEntry.Port
 			}
 

pkg/hostagent/dns/dns.go

@@ -78,11 +78,7 @@ func newStaticClientConfig(ips []string) (*dns.ClientConfig, error) {
 
 func (h *Handler) lookupCnameToHost(cname string) string {
 	seen := make(map[string]bool)
-	for {
-		// break cyclic definition
-		if seen[cname] {
-			break
-		}
+	for !seen[cname] { // break cyclic definition
 		if _, ok := h.cnameToHost[cname]; ok {
 			seen[cname] = true
 			cname = h.cnameToHost[cname]

pkg/hostagent/dns/dns_test.go

@@ -53,6 +53,9 @@ func TestDNSRecords(t *testing.T) {
 			"host.lima.internal": "10.10.0.34",
 			"my.host":            "host.lima.internal",
 			"default":            "my.domain.com",
+			"cycle1.example.com": "cycle2.example.com",
+			"cycle2.example.com": "cycle1.example.com",
+			"self.example.com":   "self.example.com",
 		},
 	}
 
@@ -120,6 +123,23 @@ func TestDNSRecords(t *testing.T) {
 			assert.Assert(t, regexMatch(dnsResult.String(), tc.expectedCNAME))
 		}
 	})
+
+	t.Run("test cyclic CNAME records", func(t *testing.T) {
+		tests := []struct {
+			testDomain    string
+			expectedCNAME string
+		}{
+			{testDomain: "cycle1.example.com", expectedCNAME: `cycle1.example.com.`},
+			{testDomain: "self.example.com", expectedCNAME: `self.example.com.`},
+		}
+
+		for _, tc := range tests {
+			req := new(dns.Msg)
+			req.SetQuestion(dns.Fqdn(tc.testDomain), dns.TypeCNAME)
+			h.ServeDNS(w, req)
+			assert.Assert(t, regexMatch(dnsResult.String(), tc.expectedCNAME))
+		}
+	})
 }
 
 type TestResponseWriter struct{}