[GCU] bgpl and bgp_prefix test report syslog err when do removal

[wen587]

Description

Please read below info after finish Steps to reproduce the issue

I guess this issue come from below logic:

The whole config removal is split to two action:

• remove admin_status as it is not create-only field
• remove the left fields together as they are create-only fields

When admin_status was removed, the config looks like we are do a 'SET' option to modify the bgp monitor from

    "BGP_MONITORS": {
        "11.0.0.1": {
            "admin_status": "up",
            "asn": "65100",
            "holdtime": "180",
            "keepalive": "60",
            "local_addr": "10.1.0.32",
            "name": "BGPMonitor",
            "nhopself": "0",
            "rrclient": "0"
        }
    }

to the one without admin_status.

    "BGP_MONITORS": {
        "11.0.0.1": {
            "asn": "65100",
            "holdtime": "180",
            "keepalive": "60",
            "local_addr": "10.1.0.32",
            "name": "BGPMonitor",
            "nhopself": "0",
            "rrclient": "0"
        }
    }

But we are not actually do the 'SET' option, just a list of removal.

Steps to reproduce the issue

1. Apply BGP_Monitor config

admin@vlab-01:~/bgpl$ cat add.json
[ {
  "op": "add",
  "path": "/BGP_MONITORS",
  "value": {
   "11.0.0.1": {
    "admin_status": "up",
    "asn": "65100",
    "holdtime": "180",
    "keepalive": "60",
    "local_addr": "10.1.0.32",
    "name": "BGPMonitor",
    "nhopself": "0",
    "rrclient": "0"
   }
  }
 }
]
admin@vlab-01:~/bgpl$ sudo config apply-patch add.json
Patch Applier: Patch application starting.
Patch Applier: Patch: [{"op": "add", "path": "/BGP_MONITORS", "value": {"11.0.0.1": {"admin_status": "up", "asn": "65100", "holdtime": "180", "keepalive": "60", "local_addr": "10.1.0.32", "name": "BGPMonitor", "nhopself": "0", "rrclient": "0"}}}]
...
Patch Applier: Verifying patch updates are reflected on ConfigDB.
Patch Applier: Patch application completed.
Patch applied successfully.

2. Remove BGPMONITOR config and cat syslog err
   2.1 remove bgpmonitor config

admin@vlab-01:~/bgpl$ cat rm.json
[
 {
  "op": "remove",
  "path": "/BGP_MONITORS"
 }
]
admin@vlab-01:~/bgpl$ sudo config apply-patch rm.json
...
Patch Applier: The patch was sorted into 2 changes:
Patch Applier:   * [{"op": "remove", "path": "/BGP_MONITORS/11.0.0.1/admin_status"}]     <=======
Patch Applier:   * [{"op": "remove", "path": "/BGP_MONITORS"}]                     <============
Patch Applier: Applying 2 changes in order:
Patch Applier:   * [{"op": "remove", "path": "/BGP_MONITORS/11.0.0.1/admin_status"}]
Patch Applier:   * [{"op": "remove", "path": "/BGP_MONITORS"}]
Patch Applier: Verifying patch updates are reflected on ConfigDB.
Patch Applier: Patch application completed.
Patch applied successfully.

2.2 syslog when removal

admin@vlab-01:~$ show logging -f | grep ERR
Mar 25 09:23:23.886809 vlab-01 ERR bgp#bgpcfgd: Peer '(default|11.0.0.1)': Can't update the peer. Only 'admin_status' attribute is supported

Describe the results you received

Syslog have error when do removal

Describe the results you expected

Two ways of fix in my mind:

1. Make sure syslog doesn't report ERR
2. Ignore this kind of error. The bgp monitor config removal is successful as it is not a real issue.

Additional information you deem important (e.g. issue happens only occasionally)

Output of show version

(paste your output here)

[ghooo]

This seems like an issue in bgpcfgd. The operation is removing admin_status using SET operation, but the bgpcfgd is complaining it is only possible to remove admin_status which is what we are doing. This is a contradiction.

[wen587]

fix by #2120

[wen587]

For bgp_prefix test, Log analyzer will also report err:
ERR bgp#bgpcfgd: BGPAllowListMgr::Received BGP ALLOWED 'SET' message with no prefixes specified: {'NULL': 'NULL'}
This is also fixed by above optimization group PR.