[VM]Add BGPSentinel testcase and testplan

docs/testplan/BGP-BGPSentinel.md

@@ -0,0 +1,92 @@
+- [Overview](#overview)
+    - [Scope](#scope)
+    - [Testbed](#testbed)
+- [Setup configuration](#setup-configuration)
+- [Test cases](#test-cases)
+
+## Overview
+The purpose is to test that BGPSentinel (BGPS) host will setup an IBGP connection to FRR. BGPSentinel (BGPS) will advertise and withdraw routes to FRR. As BGPSentinel session is IBGP and not directly connected to the DUT, this feature relies on V4 and V6 next hop tracking resolve via default configuration in FRR.
+
+### Scope
+The test is targeting a running SONIC system with fully functioning configuration. The purpose of the test is not to test specific API, but functional testing of BGPSentinel configuration on SONIC system.
+
+### Testbed
+The test will run on the following testbeds:
+* t1-lag (vs)
+
+```txt
+              +-----+------+
+              |  VM2 (T2)  |
+              +-----+------+
+                    |
+                    |
+                    |
++-------------------+---------------------+                +-------------------+
+|                                         |                |                   |
+|                DUT (T1)                 |................| PTF (BGPSentinel) |
+|                                         |                |                   |
++-------+-------------------------+-------+                +-------------------+
+        |                         |
+        |                         |                   (Advertise: 10.0.0.0/24, community:
+        |                         |                   no-export, higher local-preference)
+  +-----+------+            +-----+------+
+  |  VM0 (T0)  |            |  VM1 (T0)  |
+  +------------+            +------------+
+(Advertise: 10.0.0.0/24)
+
+-----       EBGP Session
+.....       IBGP Session
+```
+
+## Setup configuration
+This test doesn't require any configuration in ansible deployment. IBGP session between BGPSentinel (BGPS) host and DUT are created in set up phase of this case and are cleaned in tear down phase of this case. BGPSentinel (BGPS) host is simulated by exabgp in PTF.
+
+## Test
+The test will configure BGPSentinel session and then check that IBGP session would be setup between BGPSentinel (BGPS) host and DUT. After session set up, BGPSentinel (BGPS) will advertise routes with higher local-preference and no-export community. These routes will act as best-path in DUT, which would suppress routes received from t0. The test will cover both V4 and V6 BGPSentinel session.
+
+## Test cases
+### Test case # 1 - BGPSentinel to DUT over IBGP V4 session
+
+#### Test Objective
+Test BGPSentinel V4 session would be used to advertise and withdraw V4/V6 routes
+
+#### Test Steps
+1. Setup IBGP V4 session from BGPSentinel (BGPS) host to DUT (Simulated from ptf using exabgp to DUT).
+2. Find V4 and V6 routes advertised from T0.
+3. Check these routes are advertised to EBGP peers.
+4. In ptf, advertise the same routes with higher local-preference and no-export community to DUT.
+5. Check these routes are suppressed and not advertised to EBGP peers.
+6. In ptf, withdraw these routes to DUT.
+7. Check these routes are advertised to EBGP peers.
+
+### Test case # 2 - BGPSentinel to DUT over IBGP V6 session
+Add BGPSentinel to DUT and check IBGP V6 session would set up and advertise V4/V6 routes
+
+#### Test Objective
+Test BGPSentinel V6 session would be used to advertise and withdraw V4/V6 routes
+
+#### Test Steps
+1. Setup IBGP V6 session from BGPSentinel (BGPS) host to DUT (Simulated from ptf using exabgp to DUT).
+2. Find V4 and V6 routes advertised from T0.
+3. Check these routes are advertised to EBGP peers.
+4. In ptf, advertise the same routes with higher local-preference and no-export community to DUT.
+5. Check these routes are suppressed and not advertised to EBGP peers.
+6. In ptf, withdraw these routes to DUT.
+7. Check these routes are advertised to EBGP peers.
+
+### Test case # 3 - Soft/Hard reset IBGP V4 and V6 Session in DUT
+Soft/Hard reset IBGP session, after IBGP session recovers, DUT would still suppress the route to T2 peers
+
+#### Test Objective
+Test after soft/hard reset IBGP session, DUT would still select right best path
+
+#### Test Steps
+1. Setup IBGP V6 session from BGPSentinel (BGPS) host to DUT (Simulated from ptf using exabgp to DUT).
+2. Find V4 and V6 routes advertised from T0.
+3. Check these routes are advertised to EBGP peers.
+4. In ptf, advertise the same routes with higher local-preference and no-export community to DUT.
+5. Check these routes are suppressed and not advertised to EBGP peers.
+6. Soft/Hard reset IBGP session, wait for IBGP session setup.
+7. Check these routes are till suppressed and not advertised to EBGP peers.
+8. In ptf, withdraw these routes to DUT.
+9. Check these routes are advertised to EBGP peers.

tests/bgp/bgp_helpers.py

@@ -30,6 +30,11 @@
 BGPMON_CONFIG_FILE = '/tmp/bgpmon.json'
 BGP_MONITOR_NAME = "bgp_monitor"
 BGP_MONITOR_PORT = 7000
+BGPSENTINEL_CONFIG_FILE = '/tmp/bgpsentinel.json'
+BGP_SENTINEL_NAME_V4 = "bgp_sentinelV4"
+BGP_SENTINEL_NAME_V6 = "bgp_sentinelV6"
+BGP_SENTINEL_PORT_V4 = 7900
+BGP_SENTINEL_PORT_V6 = 7901
 BGP_ANNOUNCE_TIME = 30  # should be enough to receive and parse bgp updates
 CONSTANTS_FILE = '/etc/sonic/constants.yml'
 EXABGP_BASE_PORT = 5000