avoid printing error if no neighbors are present (sonic-net#2502)

* avoid printing error if no neighbors are present

Signed-off-by: Arvindsrinivasan Lakshmi Narasimhan <arlakshm@microsoft.com>

tests/bgp_commands_test.py

@@ -97,6 +97,14 @@
 Error: bgp summary from bgp container not in json format
 """
 
+show_error_no_v6_neighbor = """\
+No IPv6 neighbor is configured
+"""
+
+show_error_no_v4_neighbor = """\
+No IPv4 neighbor is configured
+"""
+
 show_bgp_summary_v4_chassis = """\
 
 IPv4 Unicast Summary:
@@ -319,3 +327,31 @@ def test_bgp_summary_v4_all_chassis(
         print("{}".format(result.output))
         assert result.exit_code == 0
         assert result.output == show_bgp_summary_v4_all_chassis
+
+    @pytest.mark.parametrize('setup_single_bgp_instance',
+                             ['show_bgp_summary_no_neigh'], indirect=['setup_single_bgp_instance'])
+    def test_bgp_summary_no_v4_neigh(
+            self,
+            setup_bgp_commands,
+            setup_single_bgp_instance):
+        show = setup_bgp_commands
+        runner = CliRunner()
+        result = runner.invoke(
+            show.cli.commands["ipv6"].commands["bgp"].commands["summary"], [])
+        print("{}".format(result.output))
+        assert result.exit_code == 0
+        assert result.output == show_error_no_v6_neighbor
+
+    @pytest.mark.parametrize('setup_single_bgp_instance',
+                             ['show_bgp_summary_no_neigh'], indirect=['setup_single_bgp_instance'])
+    def test_bgp_summary_no_v6_neigh(
+            self,
+            setup_bgp_commands,
+            setup_single_bgp_instance):
+        show = setup_bgp_commands
+        runner = CliRunner()
+        result = runner.invoke(
+            show.cli.commands["ip"].commands["bgp"].commands["summary"], [])
+        print("{}".format(result.output))
+        assert result.exit_code == 0
+        assert result.output == show_error_no_v4_neighbor

tests/conftest.py

@@ -169,6 +169,9 @@ def setup_single_bgp_instance(request):
         bgp_mocked_json = os.path.join(
             test_path, 'mock_tables', 'dummy.json')
 
+    def mock_show_bgp_summary_no_neigh(vtysh_cmd, bgp_namespace, vtysh_shell_cmd=constants.RVTYSH_COMMAND):
+        return "{}"
+
     def mock_show_bgp_summary(vtysh_cmd, bgp_namespace, vtysh_shell_cmd=constants.RVTYSH_COMMAND):
         if os.path.isfile(bgp_mocked_json):
             with open(bgp_mocked_json) as json_data:
@@ -217,6 +220,9 @@ def mock_run_show_ip_route_commands(request):
     elif request.param == 'ip_route_for_int_ip':
         _old_run_bgp_command = bgp_util.run_bgp_command
         bgp_util.run_bgp_command = mock_run_bgp_command_for_static
+    elif request.param == "show_bgp_summary_no_neigh":
+        bgp_util.run_bgp_command = mock.MagicMock(
+            return_value=mock_show_bgp_summary_no_neigh("", ""))
     else:
         bgp_util.run_bgp_command = mock.MagicMock(
             return_value=mock_show_bgp_summary("", ""))

utilities_common/bgp_util.py

@@ -215,8 +215,10 @@ def get_bgp_summary_from_all_bgp_instances(af, namespace, display):
         except ValueError:
             ctx.fail("bgp summary from bgp container not in json format")
 
+        # exit cli command without printing the error message
         if key not in cmd_output_json:
-            ctx.fail("bgp summary from bgp container in invalid format")
+            click.echo("No IP{} neighbor is configured".format(af))
+            exit()
 
         device.current_namespace = ns