Lbspec

Lbspec is an RSpec plugin for easy Loadbalancer testing.

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

# spec/spec_helper.rb
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(%w(node_b node_c)) }
  it { should respond('200 OK') }
end

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

describe 'vhost_c:80' do
  it { should transfer(%w(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(%w(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(%w(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

describe 'loadbalancer' do
  it do should healthcheck('node_c')
      .include('/test/healthcheck').from('192.168.1.1')
  end
end

describe 'loadbalancer' do
  it { should healthcheck('node_c').include('/test/healthcheck').interval(5) }
end

You will get a result:

$ bundle exec rspec spec.rb

vhost_a
  should transfer requests to node_a.
  should respond 200 OK.
vhost_b
  should transfer requests to ["node_b", "node_c"].
  should respond 200 OK.
vhost_c:80
  should transfer requests to ["node_b", "node_c"] port 80.
  should respond 404.
vhost_c:80
  should transfer requests to ["node_b", "node_c"] port 53 udp.
vhost_c:80/test/
  should transfer requests to node_c http.
  should respond 200 OK http.
vhost_c:443
  should transfer requests to ["node_b", "node_c"] port 80 https via /test/.
  should respond 200 OK https via /test/.
vhost_c:443/test/
  should transfer requests to ["node_b", "node_c"] port 80 https.
  should respond 200 OK
vhost_c:80/test/
  should transfer requests to node_c http from node_a.
loadbalancer
  should healthcheck node_c including /test/healthcheck from 192.168.1.1.
loadbalancer
  should healthcheck node_c including /test/healthcheck at interval of 5 sec.

Finished in 5.1 seconds
16 examples, 0 failures
$

Add this line to your application's Gemfile:

gem 'lbspec'

And then execute:

$ bundle

Or install it yourself as:

$ gem install lbspec

You can use lbspec to test load balancers.

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

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 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.

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.

You can use Logger to analyze. You can use Logger if you put codes in spec files or spec_helpers like this:

Lbspec::Util.log_level = Logger::WARN

or

Lbspec::Util.logger = Logger.new('test.log')

The default Logger show Logger::ERROR level on STDOUT.

#healthcheck tests if a load balancer healthchecks to target nodes.

You can use following chains with #healthcheck.

• include
  • Tests if healthchecks include string.
• from
  • Tests if healthchecks are from specific address.
• interval
  • Tests if healthchecks are at intervals of specific time.
• port
  • Tests if healthchecks are on specified port on target nodes.
• icmp
  • Tests if healthchecks are icmp.
• tcp
  • Tests if healthchecks are tcp.
• udp
  • Tests if healthchecks are udp.

• 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.

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

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

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