override default ACL for system control plane

[PieterL75]

Enhancement summary

This request is to create a design variable, that sets the default control-plane-acl and applies that to all (and default) vrf (ipv4 and ipv6)
If a VRF requires more access, then it can use the structured_config to override that default

Which component of AVD is impacted

eos_designs

Use case example

The default-control-plane-acl is too open for our company standards. (allowing telnet is a red flag, even if the service is not running)
This setting will lockdown the control plane more strict on a structured way.

Describe the solution you would like

A standard way to secure the control plane on all vrf's, and an exception to open more access.

Describe alternatives you have considered

We can create a more strict one, but then we need to apply that to each VRF that is added to the system.
Currently we set that acl using structured_config int he 'vrfs', but it can be forgotten, opening access that is unwanted.

Additional context

No response

Contributing Guide

• I agree to follow this project's Code of Conduct

[ClausHolbechArista]

It will help with a snip of config as well as a suggestion for a data model to do this. Notice we have ipv4_acls in eos_designs which may or may not be usable for this?

[PieterL75]

This is what I would like to able to generate :

# eos_config
  - name: SEC-COPP_STRICT-V4-IN
    # This acl is based on the default-control-plane-acl. https://arista.my.site.com/AristaCommunity/s/article/default-control-plane-acl-explained
    # Removed protocols: tcp/telnet, tcp/www, tcp/snmp, tcp/netconf-ssh, tcp/gnmi, udp/nootps, udp/bootpc, udp/ntp, udp/ptp-event, udp/ptp-general, tcp/5900-5910
    # tcp/ssh, tcp/https and udp/snmp are limited within the service using vrf specific ACLs
    # routing protocols are limited by dynamic ACLs based on neighbours.
    counters_per_entry: true
    sequence_numbers:
      - sequence: 10
        action: permit icmp any any
      - sequence: 20
        action: permit ip any any tracked
      - sequence: 30
   <snipped>
      - sequence: 290
        action: permit udp any eq lsp-ping any

# design var
default_copp_acl: SEC-COPP_STRICT-V4-IN

If then a VRF is defined in the NETWORK_SERVICES, each device where the VRF is applied should have this config is generated:

control_plane:
  ipv4_access_groups:
  - acl_name: SEC-COPP_STRICT-V4-IN
    vrf: VRF1
  - acl_name: SEC-COPP_STRICT-V4-IN
    vrf: VRF2

and final config is:

system control-plane
  ip access-group SEC-COPP_STRICT-V4-IN vrf VRF1
  ip access-group SEC-COPP_STRICT-V4-IN vrf VRF2

if a VRF requires the default copp acl, then it can be overriden with a structured_config

    vrfs:
      - name: VRF3
        structured_config:
          system:
            control_plane:
              ipv4_access_groups:
                  - acl_name: default-control-plane-acl
                    vrf: VRF3

Same should got vor IPv6 ofcourse