Class: Beaker::DSL::InstallUtils::FeatureFlags

Inherits:
Object
  • Object
show all
Defined in:
lib/beaker-pe/install/feature_flags.rb

Overview

This helper class encapsulates querying feature flag settings from options which can be used to drive Beaker’s install behavior around new or experimental features, typically in the PE Modules.

Also handles initializing feature flag settings from environment variables for CI. In this way, flags can be pulled in without needing to munge Beaker’s config file which is often handled inside of a script in Jenkins.

Flags are expected to be found in a feature_flags hash in the options under the key :feature_flags. Beaker::OptionHash should ensure that all keys end up as symbols. If you are programatically constructing the answers, you must take care to use merge() to add elements.

All flag keys are expected to be downcased with underscores.

Environment variables may be uppercased.

Examples:

The use of the pe-modules-next package is handled by:

:answers => {
  :feature_flags => {
    :pe_modules_next => true
  }
}

Constant Summary collapse

FLAGS = 
%w{
  pe_modules_next
}.freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ FeatureFlags

Returns a new instance of FeatureFlags.



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# File 'lib/beaker-pe/install/feature_flags.rb', line 33

def initialize(options)
  @options = options
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



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# File 'lib/beaker-pe/install/feature_flags.rb', line 31

def options
  @options
end

Instance Method Details

#flag?(flag) ⇒ Boolean?

Returns the boolean state of the flag as found in options, or if not found in the answers, then it checks for an environment variable.

Parameters:

  • String —

    flag key

Returns:

  • (Boolean, nil) —

    boolean true or false unless not found at all, then nil.



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# File 'lib/beaker-pe/install/feature_flags.rb', line 42

def flag?(flag)
  key = canonical_key(flag)
  state = flags[key] if flags?
  state = environment_flag?(key) if state.nil?

  case state
  when nil then nil
  else state.to_s == 'true'
  end
end

#register_flags! ⇒ Object

Updates options[:feature_flags] with any environment variables found based on FLAGS, but if and only if they are not already present.

(existing :answers take precedence)



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# File 'lib/beaker-pe/install/feature_flags.rb', line 57

def register_flags!
  answers_with_registered_flags = answers
  answers_with_registered_flags[:feature_flags] ||= StringifyHash.new
  new_flags = answers_with_registered_flags[:feature_flags]

  FLAGS.each do |flag|
    key = canonical_key(flag)
    value = flag?(key)
    if !new_flags.include?(key) && !value.nil?
      new_flags[key] = value
    end
  end

  options.merge!(
    :answers => answers_with_registered_flags
  ) if !new_flags.empty?

  options
end