Default policy if statement was not found

[sebasttiano]

Hi, everybody.

Is it correct that gobgp starts with default policies (no policies) if some set for example is missing in the config by mistake?

Part of the config:

 ........
  defined-sets:
    neighbor-sets:
      - neighbor-set-name: all_borders
         neighbor-info-list: ['10.12.3.1']
 ......
      - name: flowspec_to_universal_routers
        conditions:
          match-neighbor-set:
            neighbor-set: universal_routers                <---- missing in neighbor-sets statement
            match-set-options: any
          bgp-conditions:
            match-large-community-set:
              large-community-set: common_access_flowspec
              match-set-options: any
            afi-safi-in-list: ['ipv4-flowspec']
        actions:
          route-disposition: accept-route
          bgp-actions:
            set-large-community:
              options: remove
              set-large-community-method:
                communities-list: ['902:902:902']
   .....

For example, universal_routers is missing in the neighbor-set, this leads to an error at startup:
{"Error":"not found neighbor set universal_routers","Topic":"Policy","level":"error","msg":"failed to create routing policy","time":"2024-01-17T15:19:05+01:00"}

But gobgp still runs without any policy at all, which leads to unexpected behavior

What I expect from gobgp: not to run with invalid config

[fujita]

Please send a pull request.