apply route-map and prefix-list only to nodes that have the BGP peering applied

[PieterL75]

I have a tenant with a vrf. That vrf has SVI's over 6 nodes.
one node forsees external BGP peerings and those are secured with route-map and prefix-lists.
I used the vrf/structured_config to define the routemap and prefix lists.

But now I see that those are applied to all nodes, and not only to the those with the BGP peering..

Is there a cleaner way to do this ? I don't like that orphaned config, as it looks like something was configured incorrect

[ClausHolbechArista]

For now the only way would be to use some inline-jinja to check if you are on one of the 6 nodes.

Written from memory, to may need some adjustment. Refer to Ansible docs for guidance.

structured_config: |-
  {% if inventory_hostname in ['node1', 'node2'] %}
  route_maps: ...
  {% elif %}
  null
  {% endif %}

We have implemented ipv4_prefix_list_catalog, but it is currently only used by l3_interfaces defined under the nodes.

We would like to implement similar "catalogs" of route-maps and other areas which will be applied when referred to under the BGP peers, peer-groups etc. So the route-maps and prefix-lists them selves would also get proper models in eos_designs.

[ClausHolbechArista]

BTW this structured config would go under the VRF, since structured config there is placed at the root of the eos_cli_config_gen model.

[PieterL75]

Looks promising.
thx for the fast feedback

[PieterL75]

I ended up creating separate host-groups in my inventory file.
and then a group_var per group of devices that have custom_structured_configuration_myhostgroup_prefix_lists
that way I can control what prefixlist/routemap shows up on what devices.

not ideal, as I have to manually update the inventory file when a new device is added and needs those prefix/route-maps

[PieterL75]

I wrote a 'conditional catalog' to kind of get around it..
There is a catalog created like this

_catalog_prefix_lists:
  - name: PL-BE-EBGP4-DEFAULT
    _apply_groups:
      - FABRIC
    _apply_hosts:
    sequence_numbers:
      - sequence: 10
        action: permit 0.0.0.0/0

_catalog_ipv6_prefix_lists:
  - name: PL-BE-EBGP6-DEFAULT
    _apply_groups:
      - FABRIC
    _apply_hosts:
    sequence_numbers:
      - sequence: 10
        action: permit ::/0

any design variable can be appended to _catalog_

• prefix_lists
• route_maps
• match_list
• and so one

then I added a custom_structured_configuration_prefix generated_

custom_structured_configuration_prefix:  
  - custom_structured_configuration_
  - generated_

and an ansible set_fact

    - name: Build Conditional Catalogs # noqa: run-once[task]
      # yamllint disable rule:line-length
      ansible.builtin.set_fact:
        "generated_{{ item | replace('_catalog_', '') }}": "{% set catalog = query('ansible.builtin.vars', item) | first %}{% if catalog | default(None) %}{% set ns = namespace(result=[]) %}{% for catalogitem in catalog %}{% if ('_apply_groups' in catalogitem and catalogitem._apply_groups and group_names | select('in', catalogitem._apply_groups) | list | count > 0) or ('_apply_hosts' in catalogitem and catalogitem._apply_hosts and inventory_hostname in catalogitem._apply_hosts) %}{% set ns.result = ns.result + [dict(catalogitem.items() | rejectattr(0, 'in', ['_apply_groups', '_apply_hosts'] | list))] %}{% endif %}{% endfor %}{{ ns.result }}{% endif %}"
      # yamllint enable rule:line-length
      with_items: "{{ query('ansible.builtin.varnames', '^_catalog_.+') }}"

now any variable starting with catalog will create a generated_ variable, and only if any of the apply_group is part of the ansible groups, or if the inventory_hostname matches the hostname

Works pretty good :-)

of course, I still have to manually decide what prefix list, route map, access-list goes on what devices, but at least they are not lingering on devices they are not needed on

@ClausHolbechArista

[PieterL75]

This works fine, for all kind of variables.

• access_lists ipv4/ipv6
• preffix_lists ipv4/ipv6
• route_maps
• match_list_input