# Managing GoBGP with Your Favorite Language

This page explains how to managing GoBGP with your favorite Language.
You can use any language supported by [gRPC](http://www.grpc.io/) (10
languages are supported now). This page gives an example in Python,
Ruby, C++ and Node.js. It assumes that you use Ubuntu 14.04 (64bit).

## Contents

- [Python](#python)
- [Ruby](#ruby)
- [C++](#cpp)
- [Node.js](#nodejs)

## <a name="python"> Python

### Installing LinuxBrew

We use LinuxBrew to simplify the instruction.
```bash
$ sudo apt-get update
$ sudo apt-get install -y build-essential curl git python-dev python-pip m4 ruby
$ ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/linuxbrew/go/install)"
$ export PATH=$HOME/.linuxbrew/bin:$PATH
$ brew doctor
```
It's useful to add '$HOME/.linuxbrew/bin' to your PATH environment variable.

And then add configuration to load libs under '.linuxbrew'.
```
$ echo "$HOME/.linuxbrew/lib" | sudo tee /etc/ld.so.conf.d/grpc.conf
$ sudo ldconfig
```

### Installing gRPC and Python Libraries

We install gRPC and python liblaries in python virtual environment by using LinuxBrew.
These steps are based on [gRPC HomeBrew](https://github.com/grpc/homebrew-grpc).

```bash
$ sudo apt-get update
$ sudo apt-get install python-virtualenv
$ cd $GOPATH/src/github.com/osrg/gobgp/tools/grpc/python
$ virtualenv venv
$ source ./venv/bin/activate
$ curl -fsSL https://goo.gl/getgrpc | bash -s python
$ sudo ldconfig
```

### Generating Stub Code

We need to generate stub code GoBGP at first.
```bash
$ cd $GOPATH/src/github.com/osrg/gobgp/tools/grpc/python
$ GOBGP_API=$GOPATH/src/github.com/osrg/gobgp/api
$ protoc  -I $GOBGP_API --python_out=. --grpc_out=. --plugin=protoc-gen-grpc=`which grpc_python_plugin` $GOBGP_API/gobgp.proto
```

### Get Neighbor

Here is an example for getting neighbor's information and we assumed that it's created in 'get_neighbor.py' under '$GOPATH/src/github.com/osrg/gobgp/tools/grpc/python'.
```python
import gobgp_pb2
import sys

_TIMEOUT_SECONDS = 10


def run(gobgpd_addr, neighbor_addr):
    with gobgp_pb2.early_adopter_create_GobgpApi_stub(gobgpd_addr, 8080) as stub:
        peer = stub.GetNeighbor(gobgp_pb2.Arguments(rf=4, name=neighbor_addr), _TIMEOUT_SECONDS)
        print("BGP neighbor is %s, remote AS %d" % (peer.conf.remote_ip, peer.conf.remote_as))
        print("  BGP version 4, remote router ID %s" % ( peer.conf.id))
        print("  BGP state = %s, up for %s" % ( peer.info.bgp_state, peer.info.uptime))
        print("  BGP OutQ = %d, Flops = %d" % (peer.info.out_q, peer.info.flops))
        print("  Hold time is %d, keepalive interval is %d seconds" % ( peer.info.negotiated_holdtime, peer.info.keepalive_interval))
        print("  Configured hold time is %d, keepalive interval is %d seconds" % ( peer.conf.holdtime, peer.conf.keepalive_interval))
        print("")

if __name__ == '__main__':
    gobgp = sys.argv[1]
    neighbor = sys.argv[2]
    run(gobgp, neighbor)
```

We need to import gobgp_pb2 and call 'early_adopter_create_GobgpApi_stub' in your code.

Let's run this script.

```bash
$ source ./venv/bin/activate
(venv)$ python get_neighbor.py 10.0.255.1 10.0.0.1
BGP neighbor is 10.0.0.1, remote AS 65001
  BGP version 4, remote router ID 192.168.0.1
  BGP state = BGP_FSM_ESTABLISHED, up for 9042
  BGP OutQ = 0, Flops = 0
  Hold time is 30, keepalive interval is 10 seconds
  Configured hold time is 30, keepalive interval is 10 seconds

D0821 12:31:07.821508149   91029 iomgr.c:119]                Waiting for 1 iomgr objects to be destroyed and executing final callbacks

```

We got neighbor information successfully.

## <a name="ruby"> Ruby

### Installing LinuxBrew

See [python](#python).


### Installing gRPC and Ruby Libraries

```bash
$ curl -fsSL https://goo.gl/getgrpc | bash -s ruby
$ sudo ldconfig
```

### Generating Stub Code

We need to generate stub code GoBGP at first.
```bash
$ cd $GOPATH/src/github.com/osrg/gobgp/tools/grpc/ruby
$ GOBGP_API=$GOPATH/src/github.com/osrg/gobgp/api
$ protoc  -I $GOBGP_API --ruby_out=. --grpc_out=. --plugin=protoc-gen-grpc=`which grpc_ruby_plugin` $GOBGP_API/gobgp.proto
```

### Get Neighbor

Here is an example for getting neighbor's information.
```ruby
require 'gobgp'
require 'gobgp_services'

host = 'localhost'
host = ARGV[0] if ARGV.length > 0

stub = Api::Grpc::Stub.new("#{host}:8080")
arg = Api::Arguments.new()
stub.get_neighbors(arg).each do |n|
    puts "BGP neighbor is #{n.conf.remote_ip}, remote AS #{n.conf.remote_as}"
    puts "\tBGP version 4, remote route ID #{n.conf.id}"
    puts "\tBGP state = #{n.info.bgp_state}, up for #{n.info.uptime}"
    puts "\tBGP OutQ = #{n.info.out_q}, Flops = #{n.info.flops}"
    puts "\tHold time is #{n.info.negotiated_holdtime}, keepalive interval is #{n.info.keepalive_interval} seconds"
    puts "\tConfigured hold time is #{n.conf.holdtime}"
end
```

Let's run this script.

```bash
$ruby -I . ./get_neighbors.rb
BGP neighbor is 192.168.10.2, remote AS 65001
    BGP version 4, remote route ID <nil>
    BGP state = BGP_FSM_ACTIVE, up for 0
    BGP OutQ = 0, Flops = 0
    Hold time is 0, keepalive interval is 0 seconds
    Configured hold time is 90
BGP neighbor is 192.168.10.3, remote AS 65001
    BGP version 4, remote route ID <nil>
    BGP state = BGP_FSM_ACTIVE, up for 0
    BGP OutQ = 0, Flops = 0
    Hold time is 0, keepalive interval is 0 seconds
    Configured hold time is 90
D0827 18:43:24.628846574    3379 iomgr.c:119] Waiting for 1 iomgr objects to be destroyed and executing final callbacks
```

## <a name="cpp"> C++

For gRPC we need so much dependencies, please make coffee and be ready!

### Install ProtoBuffers:
```bash
apt-get update
apt-get install -y gcc make autoconf automake git libtool g++ curl

cd /usr/src
wget https://github.com/google/protobuf/archive/v3.0.0-alpha-4.tar.gz
tar -xf v3.0.0-alpha-4.tar.gz
cd protobuf-3.0.0-alpha-4/
./autogen.sh
./configure --prefix=/opt/protobuf_3.0.0_alpha4
make -j 4
make install
```

### Install gRPC:
```bash
apt-get update
apt-get install -y gcc make autoconf automake git libtool g++ python-all-dev python-virtualenv

cd /usr/src/
git clone https://github.com/grpc/grpc.git
cd grpc
git submodule update --init
make -j 4
make install prefix=/opt/grpc
```

Add libs to the system path:
```bash
echo "/opt/grpc/lib" > /etc/ld.so.conf.d/grpc.conf
echo "/opt/protobuf_3.0.0_alpha4/lib" > /etc/ld.so.conf.d/protobuf.conf
ldconfig
```

We use .so compilation with golang, please use only 1.5 or newer version of Go Lang.

Clone this repository and build API example:
```bash
export PATH="$PATH:/opt//grpc/bin:/opt/protobuf_3.0.0_alpha4/bin/"

cd /usr/src
git clone https://github.com/osrg/gobgp.git
cd gobgp/gobgp/lib
go build -buildmode=c-shared -o libgobgp.so *.go
cp libgobgp.h /usr/src/gobgp/tools/grpc/cpp
cp libgobgp.so /usr/src/gobgp/tools/grpc/cpp
cp /usr/src/gobgp/api/gobgp.proto /usr/src/gobgp/tools/grpc/cpp/gobgp_api_client.proto
cd /usr/src/gobgp/tools/grpc/cpp
make
```

### Let's run it:
```bash
LD_LIBRARY_PATH=. ./gobgp_api_client

List of announced prefixes for route family: 65537

Prefix: 10.10.20.0/22
NLRI: {"nlri":{"prefix":"10.10.20.0/22"},"attrs":[{"type":1,"value":0},{"type":3,"nexthop":"0.0.0.0"}]}


List of announced prefixes for route family: 65669

Prefix: [destination:10.0.0.0/24][protocol: tcp][source:20.0.0.0/24]
NLRI: {"nlri":{"value":[{"type":1,"value":{"prefix":"10.0.0.0/24"}},{"type":3,"value":[{"op":129,"value":6}]},{"type":2,"value":{"prefix":"20.0.0.0/24"}}]},"attrs":[{"type":1,"value":0},{"type":14,"nexthop":"0.0.0.0","afi":1,"safi":133,"value":[{"value":[{"type":1,"value":{"prefix":"10.0.0.0/24"}},{"type":3,"value":[{"op":129,"value":6}]},{"type":2,"value":{"prefix":"20.0.0.0/24"}}]}]},{"type":16,"value":[{"type":128,"subtype":8,"value":"10:10"}]}]}
```

## <a name="nodejs"> Node.js

Build from source code because there is no official gRPC package for Ubuntu 14.04.
(Debian Linux and Mac OSX are much easier. See [the document](https://github.com/grpc/grpc/tree/release-0_11/src/node))


### Install Protocol Buffers:

Install protobuf v3.0.0-beta before gRPC. gRPC installation process will try to do it automatically but fail. (Probably because it tries another version of protobuf)

See [installation document](https://github.com/grpc/grpc/blob/master/INSTALL).

```bash
$ [sudo] apt-get install unzip autoconf libtool build-essential

$ wget https://github.com/google/protobuf/archive/v3.0.0-beta-1.tar.gz
$ tar zxvf v3.0.0-beta-1.tar.gz
$ cd protobuf-3.0.0-beta-1/
$ ./autogen.sh
$ ./configure
$ make
$ [sudo] make install
```

### Install gRPC:

```bash
$ [sudo] apt-get install git

$ git clone https://github.com/grpc/grpc.git
$ cd grpc
$ git submodule update --init
$ make 
$ [sudo] make install
```

### Install Node.js gRPC library:

Let's say Node.js is already installed,

```bash
npm install grpc
```

### Example

Copy protocol definition.

```bash
cp $GOPATH/src/github.com/osrg/gobgp/api/gobgp.proto .
```

Here is an example to show neighbor information.

```javascript
var grpc = require('grpc');
var api = grpc.load('gobgp.proto').gobgpapi;
var stub = new api.GobgpApi('localhost:8080', grpc.Credentials.createInsecure());

var call = stub.getNeighbors({});
call.on('data', function(neighbor) {
  console.log('BGP neighbor is', neighbor.conf.remote_ip,
              ', remote AS', neighbor.conf.remote_as);
  console.log("\tBGP version 4, remote route ID", neighbor.conf.id);
  console.log("\tBGP state =", neighbor.info.bgp_state,
              ', up for', neighbor.info.uptime);
  console.log("\tBGP OutQ =", neighbor.info.out_q,
              ', Flops =', neighbor.info.flops);
  console.log("\tHold time is", neighbor.info.negotiated_holdtime,
              ', keepalive interval is', neighbor.info.keepalive_interval, 'seconds');
  console.log("\tConfigured hold time is", neighbor.conf.holdtime);
});
call.on('end', function() {
  // do something when the server has finished sending
});
call.on('status', function(status) {
  // do something with the status
});
```

Let's run this:

```
BGP neighbor is undefined , remote AS undefined
        BGP version 4, remote route ID <nil>
        BGP state = BGP_FSM_ACTIVE , up for undefined
        BGP OutQ = 0 , Flops = 0
        Hold time is undefined , keepalive interval is undefined seconds
        Configured hold time is undefined
BGP neighbor is undefined , remote AS undefined
        BGP version 4, remote route ID <nil>
        BGP state = BGP_FSM_ACTIVE , up for undefined
        BGP OutQ = 0 , Flops = 0
        Hold time is undefined , keepalive interval is undefined seconds
        Configured hold time is undefined
```