[config] Add commands to remove BGP neighbor configuration (sonic-net#625)

Author: rvisnu

config/main.py

@@ -238,6 +238,31 @@ def _change_bgp_session_status(ipaddr_or_hostname, status, verbose):
     for ip_addr in ip_addrs:
         _change_bgp_session_status_by_addr(ip_addr, status, verbose)
 
+def _validate_bgp_neighbor(neighbor_ip_or_hostname):
+    """validates whether the given ip or host name is a BGP neighbor
+    """
+    ip_addrs = []
+    if _is_neighbor_ipaddress(neighbor_ip_or_hostname.lower()):
+        ip_addrs.append(neighbor_ip_or_hostname.lower())
+    else:
+        ip_addrs = _get_neighbor_ipaddress_list_by_hostname(neighbor_ip_or_hostname.upper())
+
+    if not ip_addrs:
+        click.get_current_context().fail("Could not locate neighbor '{}'".format(neighbor_ip_or_hostname))
+
+    return ip_addrs
+
+def _remove_bgp_neighbor_config(neighbor_ip_or_hostname):
+    """Removes BGP configuration of the given neighbor
+    """
+    ip_addrs = _validate_bgp_neighbor(neighbor_ip_or_hostname)
+    config_db = ConfigDBConnector()
+    config_db.connect()
+
+    for ip_addr in ip_addrs:
+        config_db.mod_entry('bgp_neighbor', ip_addr, None)
+        click.echo("Removed configuration of BGP neighbor {}".format(ip_addr))
+
 def _change_hostname(hostname):
     current_hostname = os.uname()[1]
     if current_hostname != hostname:
@@ -952,6 +977,21 @@ def neighbor(ipaddr_or_hostname, verbose):
     """Start up BGP session by neighbor IP address or hostname"""
     _change_bgp_session_status(ipaddr_or_hostname, 'up', verbose)
 
+#
+# 'remove' subgroup ('config bgp remove ...')
+#
+
+@bgp.group()
+def remove():
+    "Remove BGP neighbor configuration from the device"
+    pass
+
+@remove.command('neighbor')
+@click.argument('neighbor_ip_or_hostname', metavar='<neighbor_ip_or_hostname>', required=True)
+def remove_neighbor(neighbor_ip_or_hostname):
+    """Deletes BGP neighbor configuration of given hostname or ip from devices"""
+    _remove_bgp_neighbor_config(neighbor_ip_or_hostname)
+
 #
 # 'interface' group ('config interface ...')
 #

doc/Command-Reference.md

@@ -1466,6 +1466,8 @@ The list of possible BGP config commands are given below.
         startup
             all
             neighbor
+        remove
+            neighbor
 
 **config bgp shut down all**
 
@@ -1524,6 +1526,26 @@ This command is used to start up the particular IPv4 or IPv6 BGP neighbor using
   admin@sonic:~$ sudo config bgp startup neighbor SONIC02SPINE
   ```
 
+
+**config bgp remove neighbor <neighbor_ip_or_hostname>**
+
+This command is used to remove particular IPv4 or IPv6 BGP neighbor configuration using either the IP address or hostname.
+
+  - Usage:
+    sudo config bgp remove neighbor <neighbor_ip_or_hostname>
+
+- Examples:
+  ```
+  admin@sonic:~$ sudo config bgp remove neighbor 192.168.1.124
+  ```
+  ```
+  admin@sonic:~$ sudo config bgp remove neighbor 2603:10b0:b0f:346::4a
+  ```
+  ```
+  admin@sonic:~$ sudo config bgp remove neighbor SONIC02SPINE
+  ``` 
+
+
 Go Back To [Beginning of the document](#SONiC-COMMAND-LINE-INTERFACE-GUIDE) or [Beginning of this section](#BGP-Configuration-And-Show-Commands)