```ruby
module HiveTests
  class Configuration
    attr_accessor :host,
                  :port,
                  :host_shared_directory_path,
                  :docker_shared_directory_path,
                  :logger,
                  :hive_version

    def initialize(path_to_config_file = nil)
      if path_to_config_file.nil?
        load_default_variables
      else
        config = YAML.load_file(path_to_config_file)['hive']
        load_variables_from_config(config)
      end
      @logger = Logger.new(STDOUT)
    end

    private

    def load_default_variables
      @host = '192.168.99.100'
      @port = '10000'
      @host_shared_directory_path = '/Users/Shared/tmp/spec-tmp-files'
      @docker_shared_directory_path = '/tmp/spec-tmp-files'
      @hive_version = 10
    end

    def load_variables_from_config(config)
      @host = config['host']
      @port = config['port']
      @host_shared_directory_path = config['host_shared_directory_path']
      @docker_shared_directory_path = config['docker_shared_directory_path']
      @hive_version = config['hive_version'].to_i || 10
    end
  end
end
```

Allow to use ERB syntax in YAML config
user
```ruby
require 'tmpdir'

module HiveTests
  class Configuration
    attr_accessor :host,
                  :port,
                  :host_shared_directory_path,
                  :docker_shared_directory_path,
                  :logger,
                  :hive_version

    def initialize(path_to_config_file = nil)
      if path_to_config_file.nil?
        load_default_variables
      else
        interpolated = ERB.new(File.read(path_to_config_file)).result
        config = YAML.load(interpolated)['hive']
        load_variables_from_config(config)
      end
      @logger = Logger.new(STDOUT)
    end

    private

    def load_default_variables
      @host = '192.168.99.100'
      @port = 10000
      @host_shared_directory_path = '/Users/Shared/tmp/spec-tmp-files'
      @docker_shared_directory_path = '/tmp/spec-tmp-files'
      @hive_version = 10
    end

    def load_variables_from_config(config)
      @host = config['host']
      @port = config['port']
      @host_shared_directory_path = config['host_shared_directory_path']
      @docker_shared_directory_path = config['docker_shared_directory_path']
      @hive_version = config['hive_version'].to_i || 10
    end
  end
end
```
assistant