Mcrain

Mcrain helps you to use docker container in test cases. It supports redis, rabbitmq and riak (stand alone node or clustering) currently.

• install docker into Mac
• install docker into Windows

The docker daemon must be started with tcp socket option like -H tcp://0.0.0.0:2375. Because mcrain uses Docker Remote API.

After installing docker, edit the configuration file /etc/default/docker for Debian or Ubuntu, or /etc/sysconfig/docker for CentOS.

And add tcp option to DOCKER_OPTS like this:

DOCKER_OPTS="-H unix:///var/run/docker.sock -H tcp://0.0.0.0:2375"

Then restart the docker daemon.

Set DOCKER_HOST environment variable for mcrain.

export DOCKER_HOST='tcp://127.0.0.1:2375'

The port num must be equal to the port of tcp option in DOCKER_OPTS.

See the following documents for more information:

• https://docs.docker.com/reference/commandline/daemon/
• https://docs.docker.com/articles/networking/

Add this line to your application's Gemfile:

gem 'mcrain'

And then execute:

$ bundle

Or install it yourself as:

$ gem install mcrain

Mcrain.configure do |config|
  config.images[:mysql] = "mysql:5.6"
  config.images[:redis] = "redis:3.2-alpine"
  # config.images[:rabbitmq] = ...
  # config.images[:riak] = ...
  # config.images[:hbase] = ...
end

Or put .mcrain.yml file with following content

---
images:
  mysql: "mysql:5.6"
  redis: "redis:3.2-alpine"
  # rabbitmq: ...
  # riak: ...
  # hbase: ...

and load it by Mcrain.load_config:

Mcrain.load_config "/path/to/.mcrain.yml"

mcrain command accepts -c (--config) option to configure images by yaml file, and its default is .mcrain.yml.

Mcrain::Redis.new.start do |s|
  c = s.client # Redis::Client object
  c.ping
end

Mcrain::Rabbitmq.new.start do |s|
  c = s.client # RabbitMQ::HTTP::Client object
  c.list_nodes
end

Mcrain::Riak uses hectcastro/docker-riak.

Mcrain::Riak.new.start do |s|
  c = s.client # Riak::Client object
  obj = c.bucket("bucket1").get_or_new("foo")
  obj.data = data
  obj.store
end

Mcrain::Hbase uses nerdammer/hbase.

Add a line like this to /etc/hosts

Mcrain::Hbase.new.start do |s|
  c = s.client # HBase object defined by hbase-jruby
  c.list
  c[:my_table].create! :f
  c[:my_table].put 100, 'f:a' => 1, 'f:b' => 'two', 'f:c' => 3.14
  c[:my_table].get(100).double('f:c') #=> 3.14
end

$ mcrain start redis
To connect:
require 'redis'
client = Redis.new({:host=>"192.168.59.103", :port=>50669})
OK

$ mcrain stop redis
OK

$ mcrain start rabbitmq
To connect:
require 'rabbitmq/http/client'
client = RabbitMQ::HTTP::Client.new(*["http://192.168.59.103:50684", {:username=>"guest", :password=>"guest"}])
OK

$ mcrain stop rabbitmq
OK

$ mcrain start riak
To connect:
require 'riak'
client = Riak::Client.new({:nodes=>[{:host=>"192.168.59.103", :pb_port=>33152}]})
OK

$ mcrain stop riak
OK

$ export DOCKER_RIAK_PATH=/path/to/docker-riak
$ mcrain start riak 5
To connect:
require 'riak'
client = Riak::Client.new({:nodes=>[{:host=>"192.168.59.103", :pb_port=>33162}, {:host=>"192.168.59.103", :pb_port=>33160}, {:host=>"192.168.59.103", :pb_port=>33158}, {:host=>"192.168.59.103", :pb_port=>33157}, {:host=>"192.168.59.103", :pb_port=>33155}]})
OK

$ mcrain stop riak 5
OK

Add a line like this to /etc/hosts

$ mcrain start hbase
(snip)
To connect:
$CLASSPATH << "/Users/akima/.mcrain/hbase/hbase-client-dep-1.0.jar"
$LOAD_PATH << "hbase-jruby/lib"
require 'hbase-jruby'
client = HBase.new(*[{"hbase.zookeeper.quorum"=>"192.168.99.100", "hbase.zookeeper.property.clientPort"=>54489, "hbase.master.port"=>60000, "hbase.master.info.port"=>54490, "hbase.regionserver.port"=>60020, "hbase.regionserver.info.port"=>54491}])
OK

$ mcrain stop riak
(snip)
86a8dd6c13cd2c346fe9111e16f97265cb4fdb67cc67873c495622a28f0c1062
OK

use irb or something in JRuby.

Use Mcrain.before_setup hook if you don't want your test or spec always works with mcrain. Set block to Mcrain.before_setup like this:

unless ENV['WITH_MCRAIN'] =~ /true|yes|on|1/i
  Mcrain.before_setup = ->(s){
    # RSpec::Core::Pending#skip
    # https://github.com/rspec/rspec-core/blob/5fc29a15b9af9dc1c9815e278caca869c4769767/lib/rspec/core/pending.rb#L118-L124
    message = "skip examples which uses mcrain"
    current_example = RSpec.current_example
    RSpec::Core::Pending.mark_skipped!(current_example, message) if current_example
    raise RSpec::Core::Pending::SkipDeclaredInExample.new(message)
  }
end

After checking out the repo, run bin/setup to install dependencies. Then, run bin/console for an interactive prompt that will allow you to experiment. Run bundle exec mcrain to use the code located in this directory, ignoring other installed copies of this gem.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release to create a git tag for the version, push git commits and tags, and push the .gem file to rubygems.org.

1. Fork it ( https://github.com/groovenauts/mcrain/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 a new Pull Request