support parser the host contains namespace

core/manager/bootstrap.go

@@ -101,11 +101,18 @@ func (bc *BootstrapConfig) tryExpandFQDN(host string) string {
 	if strings.Contains(host, ".svc.") {
 		return host
 	}
+
 	var b strings.Builder
 	b.Grow(len(host) + len(bc.configNamespace) + len(bc.nodeDomain) + 10)
 	b.WriteString(host)
-	b.WriteString(".")
-	b.WriteString(bc.configNamespace)
+
+	// the regex for Kubernetes service is [a-z]([-a-z0-9]*[a-z0-9])?, it should not contains `.` in it
+	// if the host not contains namespace.
+	if !strings.Contains(host, ".") {
+		b.WriteString(".")
+		b.WriteString(bc.configNamespace)
+	}
+
 	b.WriteString(".svc.")
 	b.WriteString(bc.nodeDomain)
 	return b.String()

core/manager/bootstrap_test.go

@@ -24,6 +24,44 @@ import (
 	"google.golang.org/protobuf/types/known/structpb"
 )
 
+func TestTryExpandFQDN(t *testing.T) {
+	testCases := []struct {
+		desc string
+		host string
+		want string
+		bsc  *BootstrapConfig
+	}{
+		{
+			desc: "success",
+			host: "servicea",
+			want: "servicea.default.svc.cluster.local",
+			bsc: &BootstrapConfig{
+				nodeDomain:      "cluster.local",
+				configNamespace: "default",
+			},
+		},
+		{
+			desc: "success",
+			host: "servicea.bookinfo",
+			want: "servicea.bookinfo.svc.cluster.local",
+		},
+		{
+			desc: "fqdn",
+			host: "servicea.bookinfo.svc.cluster.local",
+			want: "servicea.bookinfo.svc.cluster.local",
+		},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			got := tc.bsc.tryExpandFQDN(tc.host)
+			if got != tc.want {
+				t.Errorf("tryExpandFQDN() got = %v, want %v", got, tc.want)
+			}
+		})
+	}
+
+}
+
 func TestParseMetaEnvs(t *testing.T) {
 	testCases := []struct {
 		desc         string