Feat(eos_cli_config_gen): Add global IP NAT support

[kornoa]

Change Summary

Adding support to render IP NAT global EOS configuration.

• ip nat pool ...
• ip nat kernel buffer size ...
• ip nat synchronization
• ip nat translation ...

Related Issue(s)

Fixes #2724

Component(s) name

arista.avd.eos_cli_config_gen

Proposed changes

added ip_nat

How to test

structured config:

### IP NAT ###
ip_nat:
  kernel_buffer_size: 64
  pools:
    - name: prefix_16
      prefix_length: 16
      ranges:
        - first_ip: 10.0.0.1
          last_ip: 10.0.255.254
        - first_ip: 10.1.0.0
          last_ip: 10.1.255.255
          first_port: 1024
          last_port: 65535
      utilization_log_threshold: 1
    - name: prefix_32
      prefix_length: 32
      ranges:
        - first_ip: 10.2.0.1
          last_ip: 10.2.0.1
    - name: prefix_24
      prefix_length: 24
      ranges:
        - first_ip: 10.3.0.1
          last_ip: 10.3.0.254
        - first_ip: 10.3.1.0
          last_ip: 10.3.1.255
          first_port: 1024
          last_port: 65535
      utilization_log_threshold: 100
  synchronization:
    description: 'test sync config'
    expiry_interval: 60
    local_interface: Ethernet1
    peer_address: 1.1.1.1
    port_range:
      first_port: 1024
      last_port: 65535
      split_disabled: true
    shutdown: true
  translation:
    address_selection:
      any: true
      hash_field_source_ip: true
    counters: true
    low_mark:
      percentage: 50
      host_percentage: 50
    max_entries:
      limit: 100000
      host_limit: 1000
      ip_limits:
        - ip: 10.0.0.1
          limit: 100
        - ip: 10.0.0.2
          limit: 200
    timeouts:
      - protocol: udp
        timeout: 3600
      - protocol: tcp
        timeout: 7200

result in EOS CLI config:

!
ip nat translation address selection any
ip nat translation address selection hash field source-ip
ip nat translation udp-timeout 3600
ip nat translation tcp-timeout 7200
ip nat translation max-entries 100000
ip nat translation low-mark 50
ip nat translation max-entries 1000 host
ip nat translation low-mark 50 host
ip nat translation max-entries 100 10.0.0.1
ip nat translation max-entries 200 10.0.0.2
ip nat kernel buffer size 64
ip nat pool prefix_16 prefix-length 16
   range 10.0.0.1 10.0.255.254
   range 10.1.0.0 10.1.255.255 1024 65535
   utilization threshold 1 action log
ip nat pool prefix_32 prefix-length 32
   range 10.2.0.1 10.2.0.1
ip nat pool prefix_24 prefix-length 24
   range 10.3.0.1 10.3.0.254
   range 10.3.1.0 10.3.1.255 1024 65535
   utilization threshold 100 action log
ip nat synchronization
   description test sync config
   expiry-interval 60
   shutdown
   peer-address 1.1.1.1
   local-interface Ethernet1
   port-range 1024 65535
   port-range split disabled

Checklist

User Checklist

• N/A

Repository Checklist

• My code has been rebased from devel before I start
• I have read the CONTRIBUTING document.
• My change requires a change to the documentation and documentation have been updated accordingly.
• I have updated molecule CI testing accordingly. (check the box if not applicable)

[gmuloc]

Thanks @kornoa for the PR and the updates after @ClausHolbechArista comments!

Added a couple of my own - some of them more for discussions than changes really.

[gmuloc]

LGTM

[carlbuchmann]

LGTM, thank you for this significant contribution!