BGP commander

The point of this is to integrate with ExaBGP and etcd. Basically this script will monitor keys in etcd, and announce/withdraw things via the ExaBGP api. Right now it's a proof of concept, but I plan on finishing it.

Example usage

    Usage of ./bgpcommander:
      -c=http://127.0.0.1:4001: Comma separated list of etcd cluster members
      -n="killallhumans.local": Override node's name
      -p="/tmp": Path to store healthcheck scripts

When running in conjuction with ExaBGP, a process configuration like this is inserted:

    process bgpcommander {
      encoder json;
      neighbor-changes;
      run /path/to/bgpcommander;
    }

Any of the flags available can be passed to override various defaults. You probably want to point to a real etcd cluster for example. Once you have this configured and the process is running, there are a few keys in etcd that you'll want to modify.

Creating a new route

All routes exist in the /bgp/routes directory and can be created with a couple curl commands.

    # This key is what is used to announce or withdraw routes with ExaBGP
    $ curl localhost:4001/v2/keys/bgp/routes/CUSTOM_ROUTE/config -XPUT \
         --data-urlencode value="route 172.16.1.5/32 next-hop self med 100"

    # This key is what is downloaded and ran as a healthcheck for the route.
    # As long as the script returns 0, the healthcheck is considered passing. If anything
    # else is returned, a withdraw command is used to remove the route.
    $ cat << EOF > mytest.sh
    #!/bin/sh
    dig @172.16.1.5 google.com
    EOF
    $ curl localhost:4001/v2/keys/bgp/routes/CUSTOM_ROUTE/healthcheck -XPUT \
        --data-urlencode value@mytest.sh

Assigning a route to a node

Unless you specify that a node should advertise a route, it will not. To do that you simply add to the subscribedRoutes key in etcd for that node.

    # This key should be a space separate list of route names that you would like to
    # have this node monitor and announce
    $ curl localhost:4001/v2/keys/bgp/node/killallhumans.local/subscribedRoutes -XPUT -d value="CUSTOM_ROUTE"

Checking for neighbor state

In addition to controlling routes, it's easy to grab state information about neighbors. This data is available like so:

    $ curl localhost:4001/v2/keys/bgp/node/killallhumans.local/neighbors?recursive=true
    # TODO: add sample output here, basically you have state and ip address information per neighbor