fusis

README

Fusis Balancer

Fusis Balancer is a dynamic Layer 4 Load Balancer powered by IPVS and Serf.

Running the Fusis Agent in your servers, lets the load balancer detect new nodes and route traffic to them.

There is also a HTTP API to manage your services dynamically.

IPVS

IPVS (IP Virtual Server) implements transport-layer load balancing directly in the Linux Kernel. It has been around since 1999 and is very stable/battle tested. Used by many companies such as Google, Facebook, Github, Soundcloud and so on.

IPVS is a amazing piece of software that few people really got to know, probably because its not that easy to use as it requires some some network configuration and a deep knowledge of it in order to make it work correctly.

Serf

Serf is solution for distributed cluster management, message delivery and failure detection. It's one of the bases of Consul.

Why?

The whole goal of this project is to provide an easy way to use IPVS.

Fusis Load Balancer will be responsible for detecting new/failed nodes and add/remove routes to them. It will automatically configure the network to do so.

State

This project it's under heavy development, it's not usable yet, but you can Star ⭐ the project and follow the updates.

Installation

There is compilation and runtime dependency on libnl. On a Debian based system, you should be able to build it by running:

sudo apt-get install libnl-3-dev libnl-genl-3-dev

Get this project into GOPATH:

go get -v github.com/luizbafilho/fusis

And it's dependencies:

make deps

You'll need Go 1.5 or later;

Installing IPVS

IPVS is a Kernel module. So, all you need to do is enable it via modprobe:

sudo modprobe ip_vs

While you're at it, install the IPVS command line tool too:

sudo apt-get install ipvsadm

And enable ipv4 forwarding with:

sudo sysctl -w net.ipv4.ip_forward=1

Running the project

Now that you have IPVS and fusis installed, run the project:

# Remenber, fusis binary is at $GOPATH/bin/fusis. So, add it to your system PATH
sudo fusis balancer --bootstrap

You should see something like: [GIN-debug] Listening and serving HTTP on :8000

From another host, send a HTTP request to the API querying for available services available:

curl -i {IP OF FUSIS HOST}:8000/services

And you should get:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Thu, 07 Apr 2016 21:23:18 GMT
Content-Length: 3

[]

Just for testing purposes, lets add a route to a fake IPv4 by runnging this on the fusis host:

sudo ipvsadm -A -t 10.0.0.1:80 -s rr

Then, make another request:

curl -i {FUSIS_HOST_IPV4}:8000/services

You will get that same route you just created as a response:

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Thu, 07 Apr 2016 22:08:42 GMT
Content-Length: 94

[{"Name":"","Host":"10.0.0.1","Port":80,"Protocol":"tcp","Scheduler":"rr","Destinations":[]}]

Logging

Fusis uses Logrus as its logging system. By default, Fusis logs to stdout every minute. You can change its log collection interval by passing the following command line argument:

# The argument --log-interval or -i. The value is in seconds
$> sudo fusis balancer --bootstrap --log-interval 10