pppoe: T4384: replace default-route CLI option with common CLI nodes already present for DHCP

VyOS 1.4 still leverages PPPd internals on the CLI.

pppd supports three options for a default route, none, auto, force.
* none: No default route is installed on interface up
* auto: Default route is only installed if there is yet no default route
* force: overwrite any default route

There are several drawbacks in this design for VyOS and the users. If auto is
specified, this only counted for static default routes - but what about dynamic
ones? Same for force, only a static default route got replaced but dynamic ones
did not got taken into account.

The CLI is changed and we now re-use already existing nodes from the DHCP
interface configuration:
* no-default-route:
  On link up no default route is installed, same as the previous
  default-route none

* default-route-distance:
  We can now specify the distance of this route for the routing table on the
  system. This defaults to 210 as we have for DHCP interfaces. All this will be
  migrated using a CLI migration script.

1 files changed, 9 insertions, 8 deletions

diff --git a/data/templates/frr/staticd.frr.j2 b/data/templates/frr/staticd.frr.j2
index cf8448f7f..589f03c2c 100644
--- a/data/templates/frr/staticd.frr.j2
+++ b/data/templates/frr/staticd.frr.j2
@@ -18,17 +18,18 @@ vrf {{ vrf }}
 {# IPv4 default routes from DHCP interfaces #}
 {% if dhcp is vyos_defined %}
 {%     for interface, interface_config in dhcp.items() %}
-{#         PPPoE routes behave a bit different ... #}
-{%         if interface.startswith('pppoe') and interface_config.default_route is vyos_defined and interface_config.default_route is not vyos_defined('none') %}
-{{ ip_prefix }} route 0.0.0.0/0 {{ interface }} tag 210
-{%         else %}
-{%             set next_hop = interface | get_dhcp_router %}
-{%             if next_hop is vyos_defined %}
-{{ ip_prefix }} route 0.0.0.0/0 {{ next_hop }} {{ interface }} tag 210 {{ interface_config.distance if interface_config.distance is vyos_defined }}
-{%             endif %}
+{%         set next_hop = interface | get_dhcp_router %}
+{%         if next_hop is vyos_defined %}
+{{ ip_prefix }} route 0.0.0.0/0 {{ next_hop }} {{ interface }} tag 210 {{ interface_config.dhcp_options.default_route_distance if interface_config.dhcp_options.default_route_distance is vyos_defined }}
 {%         endif %}
 {%     endfor %}
 {% endif %}
+{# IPv4 default routes from PPPoE interfaces #}
+{% if pppoe is vyos_defined %}
+{%     for interface, interface_config in pppoe.items() %}
+{{ ip_prefix }} route 0.0.0.0/0 {{ interface }} tag 210 {{ interface_config.default_route_distance if interface_config.default_route_distance is vyos_defined }}
+{%     endfor %}
+{% endif %}
 {# IPv6 routing #}
 {% if route6 is vyos_defined %}
 {%     for prefix, prefix_config in route6.items() %}