nodes: improve handling of erroneous host names

pkg/util/node/node_test.go

@@ -89,3 +89,35 @@ func TestGetPreferredAddress(t *testing.T) {
 		}
 	}
 }
+
+func TestGetHostname(t *testing.T) {
+	testCases := []struct {
+		hostName         string
+		expectedHostName string
+		expectError      bool
+	}{
+		{
+			hostName:    "   ",
+			expectError: true,
+		},
+		{
+			hostName:         " abc  ",
+			expectedHostName: "abc",
+			expectError:      false,
+		},
+	}
+
+	for idx, test := range testCases {
+		hostName, err := GetHostname(test.hostName)
+		if err != nil && !test.expectError {
+			t.Errorf("[%d]: unexpected error: %s", idx, err)
+		}
+		if err == nil && test.expectError {
+			t.Errorf("[%d]: expected error, got none", idx)
+		}
+		if test.expectedHostName != hostName {
+			t.Errorf("[%d]: expected output %q, got %q", idx, test.expectedHostName, hostName)
+		}
+
+	}
+}