Support for snmp-server host with snmp v1 and v2c

[rainmanatee]

Issue Type

• [X] New Feature

Summary

In eos_cli_config_gen snmp-settings.j2 does not properly render the snmp-server host command. The community string needs to be included in the command when the version is 1 or 2c.

Component Name

eos_cli_config_gen/templates/eos/snmp-settings.j2

Steps to reproduce

In SNMP Settings, under hosts, there is no facility to add communities, but these are a necessary component to the snmp-server host command if the snmp version is 1 or 2c:

DC2-SP01(s1)(config)#snmp-server host 1.1.1.1 vrf MGMT version 2c ?
  WORD  Community or user name

DC2-SP01(s1)(config)#snmp-server host 1.1.1.1 vrf MGMT version 2c
% Incomplete command
DC2-SP01(s1)(config)#snmp-server host 1.1.1.1 vrf MGMT version 1 ?
  WORD  Community or user name

  hosts:
    - host: < host IP address or name >
      vrf: < vrf_name >
      users:
        - username: < username >
          authentication_level: < auth | noauth | priv >
          version: < 1 | 2c | 3 >
    - host: < host IP address or name >
      vrf: < vrf_name >
      users:
        - username: < username >
          authentication_level: < auth | noauth | priv >
          version: < 1 | 2c | 3 >

Need to have communities referenced as well, so something like this:

  hosts:
    - host: < host IP address or name >
      vrf: < vrf_name >
      users:
        - username: < username >
          authentication_level: < auth | noauth | priv >
          version: < 3 >
     communities:
      - community: <community name >
         version < 1 | 2c  >
    - host: < host IP address or name >
      vrf: < vrf_name >
      users:
        - username: < username >
          authentication_level: < auth | noauth | priv >
          version: < 3 >
     communities:
      - community: <community name >
         version < 1 | 2c  >

And snmp_settings.j2 to something like:

{%         for host in snmp_server.hosts %}
{%             if host.users is arista.avd.defined %}
{%                 for user in host.users %}
{%                     if host.host is arista.avd.defined %}
{%                         set host_cli = "snmp-server host " ~ host.host %}
{%                     endif %}
{%                     if host.vrf is arista.avd.defined %}
{%                         set host_cli = host_cli ~ " vrf " ~ host.vrf %}
{%                     endif %}
{%                     if user.version is arista.avd.defined %}
{%                         set host_cli = host_cli ~ " version " ~ user.version %}
{%                         if user.version == 3 %}
{%                             set host_cli = host_cli ~ " " ~ user.authentication_level ~ " " ~ user.username %}
{%                         endif %}
{%                     endif %}
{%                 for community in host.communities %}
{%                     if host.host is arista.avd.defined %}
{%                         set host_cli = "snmp-server host " ~ host.host %}
{%                     endif %}
{%                     if host.vrf is arista.avd.defined %}
{%                         set host_cli = host_cli ~ " vrf " ~ host.vrf %}
{%                     endif %}
{%                     if community.version is arista.avd.defined %}
{%                         set host_cli = host_cli ~ " version " ~ user.version %}
{%                         if user.version == 1 or 2c %}
{%                             set host_cli = host_cli ~ " " ~ community.community  %}
{%                         endif %}
{%                     endif %}
{{ host_cli }}

[ClausHolbechArista]

Correct, the current data model and template does not support v1 and v2c for hosts. The current version key is placed under users which is not applicable for v1 and v2c. I think we should move the version field to the host-level so implement something like this:

snmp_server:
  hosts:
    - host: < host IP address or name >
      version: < 1 | 2c | 3 >
      vrf: < vrf_name >
      users:
        - username: < username >
          authentication_level: < auth | noauth | priv >
      communities: 
        - < community >

If someone would like to have the same host with multiple versions, they can just make multiple entries in the hosts list. So I suggest that we rename this issue to a feature request to support snmp v1 & v2c for snmp_server.hosts.

[burnyd]

@ClausHolbechArista So the suggestion is going to be put in a feature branch for this or follow the dev branch and file a PR with the model and j2 templating change? We can do either just let us know.

[rainmanatee]

Thanks for the guidance thus far. Can you assign this to me?