T6222: VRRP show prefix for long rfc3768-compatibility interfaces allow prefix vrrp (backport #3292)

[mergify]

Change Summary

If we use rfc3768-compatibility with long interface names like eth1.100.200 it converts the VRRP interface name name to <interface>v<VRID><IP version>
For example eth2.100.200v10v4

The limit for interface name is 15 symbols and it causes that interface name is ignoring by keepalived

VMAC interface name 'eth2.100.200v10v4' too long or invalid characters - ignoring And it uses the default prefix vrrp for such cases. It works fine, but such interfaces are not displayed in the op-mode

Allow prefix vrrp for the op-mode for show interfaces

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Code style update (formatting, renaming)
• Refactoring (no functional changes)
• Migration from an old Vyatta component to vyos-1x, please link to related PR inside obsoleted component
• Other (please describe):

Related Task(s)

• https://vyos.dev/T6222

Related PR(s)

Component(s) name

Proposed changes

How to test

set interfaces ethernet eth2 vif-s 100 vif-c 200 address '10.0.1.1/30'

set high-availability vrrp group FIRST address 203.0.113.1/24
set high-availability vrrp group FIRST interface 'eth2.100.200'
set high-availability vrrp group FIRST no-preempt
set high-availability vrrp group FIRST priority '250'
set high-availability vrrp group FIRST rfc3768-compatibility
set high-availability vrrp group FIRST vrid '10'

Before the fix we don't see interface with address 203.0.113.1

vyos@r4:~$ show interfaces 
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface     IP Address         MAC                VRF        MTU  S/L    Description
------------  -----------------  -----------------  -------  -----  -----  -------------
eth0          192.168.122.14/24  52:54:00:f1:fd:77  default   1500  u/u    WAN
eth1          -                  52:54:00:04:33:2b  default   1500  u/u    WAN
eth2          -                  52:54:00:40:2e:af  default   1500  u/u    sync
eth2.100      -                  52:54:00:40:2e:af  default   1500  u/u
eth2.100.200  10.0.1.1/30        52:54:00:40:2e:af  default   1500  u/u
eth3          -                  52:54:00:09:a4:b4  default   1500  A/D
eth4          -                  52:54:00:2c:51:09  default   1500  A/D
eth5          -                  52:54:00:f3:1d:e8  default   1500  A/D
lo            127.0.0.1/8        00:00:00:00:00:00  default  65536  u/u
              ::1/128
vti10         -                  n/a                default   1500  A/D
vyos@r4:~$ 

But actually address exits

vyos@r4:~$ ip addres show dev vrrp.10
49: [email protected]: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:00:5e:00:01:0a brd ff:ff:ff:ff:ff:ff
    inet 203.0.113.1/24 scope global vrrp.10
       valid_lft forever preferred_lft forever
vyos@r4:~$ 

After the fix, the expected interface if showing with the prefix vrrp

vyos@r4:~$ show interfaces 
Codes: S - State, L - Link, u - Up, D - Down, A - Admin Down
Interface     IP Address         MAC                VRF        MTU  S/L    Description
------------  -----------------  -----------------  -------  -----  -----  -------------
eth0          192.168.122.14/24  52:54:00:f1:fd:77  default   1500  u/u    WAN
eth1          -                  52:54:00:04:33:2b  default   1500  u/u    WAN
eth2          -                  52:54:00:40:2e:af  default   1500  u/u    sync
eth2.100      -                  52:54:00:40:2e:af  default   1500  u/u
eth2.100.200  10.0.1.1/30        52:54:00:40:2e:af  default   1500  u/u
eth3          -                  52:54:00:09:a4:b4  default   1500  A/D
eth4          -                  52:54:00:2c:51:09  default   1500  A/D
eth5          -                  52:54:00:f3:1d:e8  default   1500  A/D
lo            127.0.0.1/8        00:00:00:00:00:00  default  65536  u/u
              ::1/128
vrrp.10       203.0.113.1/24     00:00:5e:00:01:0a  default   1500  u/u
vti10         -                  n/a                default   1500  A/D
vyos@r4:~$ 

Smoketest result

Checklist:

• I have read the CONTRIBUTING document
• I have linked this PR to one or more Phabricator Task(s)
• I have run the components SMOKETESTS if applicable
• My commit headlines contain a valid Task id
• My change requires a change to the documentation
• I have updated the documentation accordingly

---

This is an automatic backport of pull request #3292 done by [Mergify](https://mergify.com).