show how to configure global policy via gRPC api

add_community_policy.go

package main

import (
        gobgp "github.com/osrg/gobgp/api"
        "golang.org/x/net/context"
        "google.golang.org/grpc"
        "time"
)

func main() {
        timeout := grpc.WithTimeout(time.Second)
        conn, _ := grpc.Dial("127.0.0.1:8080", timeout, grpc.WithBlock(), grpc.WithInsecure())
        client := gobgp.NewGobgpApiClient(conn)

        client.ModDefinedSet(context.Background(), &gobgp.ModDefinedSetArguments{
                Operation: gobgp.Operation_ADD,
                Set: &gobgp.DefinedSet{
                        Type: gobgp.DefinedType_NEIGHBOR,
                        Name: "ns0",
                        // neighbor's ip address
                        List: []string{"10.0.0.1"},
                },
        })

        stmt := &gobgp.Statement{
                Conditions: &gobgp.Conditions{
                        NeighborSet: &gobgp.MatchSet{
                                Type: gobgp.MatchType_ANY,
                                Name: "ns0",
                        },
                },
                Actions: &gobgp.Actions{
                        Community: &gobgp.CommunityAction{
                                Type:        gobgp.CommunityActionType_COMMUNITY_ADD,
                                Communities: []string{"100:100"},
                        },
                },
        }

        policy := &gobgp.Policy{
                Name:       "policy0",
                Statements: []*gobgp.Statement{stmt},
        }

        client.ModPolicy(context.Background(), &gobgp.ModPolicyArguments{
                Operation: gobgp.Operation_ADD,
                Policy:    policy,
        })

        client.ModPolicyAssignment(context.Background(), &gobgp.ModPolicyAssignmentArguments{
                Operation: gobgp.Operation_ADD,
                Assignment: &gobgp.PolicyAssignment{
                        Type:     gobgp.PolicyType_EXPORT,
                        Resource: gobgp.Resource_GLOBAL,
                        Policies: []*gobgp.Policy{policy},
                        Default:  gobgp.RouteAction_ACCEPT,
                },
        })
}