Lbspec

Lbspec is an RSpec plugin for easy Loadbalancer testing.

Installation

Add this line to your application's Gemfile:

gem 'lbspec'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lbspec

Functions

You can use lbspec to test load balancers.

#transfer

#transfer tests if a virtual host on a load balancer transfer requests to target nodes.

chains

You can use following chains with #transfer.

• port
  • Tests if a virtual host transfers requests to specified port on target nodes.
• include
  • Tests if requests a virtual host transferred include string or are matched with regular expression.
• tcp
  • Tests with tcp packets for the virtual host.
• udp
  • Tests with udp packets for the virtual host.
• http
  • Tests with an http request for the virtual host.
• https
  • Tests with an https request for the virtual host.
• from
  • Specifies which host sends to the virtual host.
• path
  • Specifies a path for http or https requests.
• options
  • Options which can be used in http or https request commands.
  • You can use options if you configure request commands or capture commands.

#respond

#respond tests if a virtual host on a load balancer respond as same as expected. You can use both a string and a regular expression as a expectation.

chains

You can use following chains with #respond.

• tcp
  • Tests with tcp packets for the virtual host.
• udp
  • Tests with udp packets for the virtual host.
• http
  • Tests with an http request for the virtual host.
• https
  • Tests with an https request for the virtual host.
• from
  • Specifies which host sends to the virtual host.
• path
  • Specifies a path for http or https requests.
• with
  • Specifies a string included in requests.
• options
  • Options which can be used in http or https request commands.
  • You can use options if you configure request commands or capture commands.

Requires

• Users need to be able to login with ssh to the target nodes.
• Users need to be able to sudo on the target nodes.
• Netcat and curl are needed on requesting host.
• Grep and ngrep are needed on capturing host.

Limitations

• Lbspec uses only ssh configuration in ~/.ssh/config

Usage

Lbspec is best described by example. First, require lbspec in your spec_helper.rb:

# spec/spec_helper.rb
require 'rspec'
require 'lbspec'

Then, create a spec like this:

require_relative 'spec_helper'

describe 'vhost_a' do
  it { should transfer('node_a') }
  it { should respond('200 OK') }
end

describe 'vhost_b' do
  it { should transfer(['node_b','node_c']) }
  it { should respond('200 OK') }
end

describe 'vhost_c:80' do
  it { should transfer(['node_b','node_c']).port(80) }
  it { should respond('404') }
end

describe 'vhost_c:80' do
  it { should transfer(['node_b','node_c']).port(53).udp }
end

describe 'vhost_c:80/test/' do
  it { should transfer('node_c').http }
  it { should respond('200 OK').http }
end

describe 'vhost_c:443' do
  it { should transfer(['node_b','node_c']).port(80).https.path('/test/' }
  it { should respond('200 OK').https.path('/test/') }
end

describe 'vhost_c:443/test/' do
  it do
    should transfer(['node_b','node_c']).port(80).https
      .options(ignore_valid_ssl: true)
  end
  it do should respond('200 OK').path('/test/').https
      .options(ignore_valid_ssl: true)
  end
end

describe 'vhost_c:80/test/' do
  it { should transfer('node_c').http.from('node_a') }
end

How it works

#transfer

1. ssh to nodes
   • ssh to the nodes which receive requests via the target virtual host
2. capture probe
   • capture packets on the nodes
3. access to the nodes with probe
   • netcat or curl to the virtual host with prove
4. judge
   • judge if expected request are captured on the capturing nodes

Contributing

1. Fork it ( http://github.com/otahi/lbspec/fork )
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request