README.md

Ligato BGP GoBGP Plugin

The Ligato GoBGP plugin is a Ligato CN-Infra Plugin implementation using GoBGP Library as source of the BGP information.

GoBGP library uses the BGP protocol to retrieve the information from the neighbour nodes (i.e. Route reflector) and reflects them to the GoBGP plugin. Currently, the GoBGP plugin accepts only the IPv4 reachable routes from the GoBGP library. The reachable routes are afterwards forwarded to all registered watchers of the GoBGP plugin.

To acquire IPv4 reachable routes using GoBGP plugin we must do 2 things:

1. Configure GoBGP library to communicate to neighbours(i.e. to Route Reflector). We can do this by injecting configuration into constructor gobgp.New(...), i.e.:

import "github.com/osrg/gobgp/config"
...
  gobgp.New(Deps{
    SessionConfig: &config.Bgp{
	  Global: config.Global{    //configuring goBGP network node
	    Config: config.GlobalConfig{
	      As:       65000,
	      RouterId: "172.18.0.1",
	      Port:     -1,
	    },
	  },      ...
      Neighbors: []config.Neighbor{   //configuring initially known neighbors
        config.Neighbor{
          Config: config.NeighborConfig{
            PeerAs:          65001,
            NeighborAddress: "172.18.0.2",
          },
        },
      },
    },
  })

or by using external yaml configuration file. For example, if we name the plugin goBgpPlugin

goBgpPlugin := gobgp.New(gobgp.Deps{
    PluginInfraDeps: *flavor.InfraDeps("goBgpPlugin", local.WithConf()),...})

then we can define absolute path to the plugin's config by adding parameter to the go program launch

[terminal]$ go run main.go --goBgpPlugin-config=/home/user/myexternalconfig.yaml

In case of using both configuration methods, the external configuration is more important and will overrride any injected configuration. 2. Become registered watcher of GoBGP plugin. We can do it by using WatchIPRoutes(...), i.e.:

	// start watching
	watchRegistration, startErr := gobgpPlugin.WatchIPRoutes("watcherName1", func(route *bgp.ReachableIPRoute) {
		fmt.Printf("Just received new IPv4 reachable route: %+v ", route)
	})
	...
	// end watching
	closeErr := watchRegistration.Close()

For further usage please look into our example.