T5340: snmp: add checks while configuring snmp listen-address with an…

[nicolas-fort]

…d without vrf

Change Summary

Add checks for snmp configuration commands.

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/T5340

Component(s) name

snmp

Proposed changes

Check listen-address parameter and vrf configuration, to avoid wrong configuration

How to test

Example 1

vyos@SNMP# run show config comm | grep "address\|snmp\|vrf"
set interfaces ethernet eth0 address 'dhcp'
set interfaces ethernet eth1 address '198.51.100.1/24'
set interfaces ethernet eth1 vrf 'MGMT'
set interfaces ethernet eth2 address '192.0.2.1/24'
set service ntp allow-client address '0.0.0.0/0'
set service ntp allow-client address '::/0'
set vrf name MGMT table '101'
[edit]
vyos@SNMP# set service snmp listen-address 198.51.100.1 
[edit]
vyos@SNMP# commit
[ service snmp ]
SNMP listen address "198.51.100.1" not configured in default vrf!

[[service snmp]] failed
Commit failed
[edit]
vyos@SNMP# set service snmp vrf MGMT 
[edit]
vyos@SNMP# commit
[edit]
vyos@SNMP# sudo netstat -putane | grep 161
udp        0      0 127.0.0.1:161           0.0.0.0:*                           0          16584      3039/snmpd          
udp        0      0 198.51.100.1:161        0.0.0.0:*                           0          16583      3039/snmpd          
udp6       0      0 ::1:161                 :::*                                0          16585      3039/snmpd          
[edit]
vyos@SNMP# 

Example2:

vyos@SNMP# run show config comm | grep "address\|snmp\|vrf"
set interfaces ethernet eth0 address 'dhcp'
set interfaces ethernet eth1 address '198.51.100.1/24'
set interfaces ethernet eth1 vrf 'MGMT'
set interfaces ethernet eth2 address '192.0.2.1/24'
set service ntp allow-client address '0.0.0.0/0'
set service ntp allow-client address '::/0'
set vrf name MGMT table '101'
[edit]
vyos@SNMP# set service snmp vrf MGMT 
[edit]
vyos@SNMP# set service snmp listen-address 192.0.2.1 
[edit]
vyos@SNMP# commit
[ service snmp ]
SNMP listen address "192.0.2.1" not configured in vrf "MGMT"!

[[service snmp]] failed
Commit failed
[edit]
vyos@SNMP# del service snmp vrf 
[edit]
vyos@SNMP# commit
[edit]
vyos@SNMP# sudo netstat -putane | grep 161
udp        0      0 127.0.0.1:161           0.0.0.0:*                           0          26344      3719/snmpd          
udp        0      0 192.0.2.1:161           0.0.0.0:*                           0          26343      3719/snmpd          
udp6       0      0 ::1:161                 :::*                                0          26345      3719/snmpd          
[edit]
vyos@SNMP# 

Example 3:

vyos@SNMP# run show config comm | grep "address\|snmp\|vrf"
set interfaces ethernet eth0 address 'dhcp'
set interfaces ethernet eth1 address '198.51.100.1/24'
set interfaces ethernet eth1 vrf 'MGMT'
set interfaces ethernet eth2 address '192.0.2.1/24'
set service ntp allow-client address '0.0.0.0/0'
set service ntp allow-client address '::/0'
set vrf name MGMT table '101'
[edit]
vyos@SNMP# set service snmp listen-address 198.51.100.1 
[edit]
vyos@SNMP# set service snmp listen-address 192.0.2.1 
[edit]
vyos@SNMP# commit
[ service snmp ]
SNMP listen address "198.51.100.1" not configured in default vrf!

[[service snmp]] failed
Commit failed
[edit]
vyos@SNMP# 

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