class Vagrant::Plugin::V2::Config

This is the base class for a configuration key defined for V2. Any configuration key plugins for V2 should inherit from this class.

Constants

UNSET_VALUE

This constant represents an unset value. This is useful so it is possible to know the difference between a configuration value that was never set, and a value that is nil (explicitly). Best practice is to initialize all variables to this value, then the {#merge} method below will “just work” in many cases.

Public Instance Methods

_detected_errors() click to toggle source

This returns any automatically detected errors.

@return [Array<String>]

# File lib/vagrant/plugin/v2/config.rb, line 145
def _detected_errors
  return [] if !@__invalid_methods || @__invalid_methods.empty?
  return [I18n.t("vagrant.config.common.bad_field",
                 fields: @__invalid_methods.to_a.sort.join(", "))]
end
_finalize!() click to toggle source

An internal finalize call that no subclass should override.

# File lib/vagrant/plugin/v2/config.rb, line 152
def _finalize!
  @__finalized = true
end
clean_up_config_object(config) click to toggle source
# File lib/vagrant/plugin/v2/config.rb, line 156
def clean_up_config_object(config)
  # Remote variables that are internal
  config.delete_if{|k,_| k.start_with?("_") }
  config
end
finalize!() click to toggle source

This is called as a last-minute hook that allows the configuration object to finalize itself before it will be put into use. This is a useful place to do some defaults in the case the user didn’t configure something or so on.

An example of where this sort of thing is used or has been used: the “vm” configuration key uses this to make sure that at least one sub-VM has been defined: the default VM.

The configuration object is expected to mutate itself.

# File lib/vagrant/plugin/v2/config.rb, line 28
def finalize!
  # Default implementation is to do nothing.
end
instance_variables_hash() click to toggle source

Returns the instance variables as a hash of key-value pairs.

# File lib/vagrant/plugin/v2/config.rb, line 125
def instance_variables_hash
  instance_variables.inject({}) do |acc, iv|
    acc[iv.to_s[1..-1]] = instance_variable_get(iv)
    acc
  end
end
merge(other) click to toggle source

Merge another configuration object into this one. This assumes that the other object is the same class as this one. This should not mutate this object, but instead should return a new, merged object.

The default implementation will simply iterate over the instance variables and merge them together, with this object overriding any conflicting instance variables of the older object. Instance variables starting with “__” (double underscores) will be ignored. This lets you set some sort of instance-specific state on your configuration keys without them being merged together later.

@param [Object] other The other configuration object to merge from,

this must be the same type of object as this one.

@return [Object] The merged object.

# File lib/vagrant/plugin/v2/config.rb, line 46
def merge(other)
  result = self.class.new

  # Set all of our instance variables on the new class
  [self, other].each do |obj|
    obj.instance_variables.each do |key|
      # Ignore keys that start with a double underscore. This allows
      # configuration classes to still hold around internal state
      # that isn't propagated.
      if !key.to_s.start_with?("@__")
        # Don't set the value if it is the unset value, either.
        value = obj.instance_variable_get(key)
        result.instance_variable_set(key, value) if value != UNSET_VALUE
      end
    end
  end

  # Persist through the set of invalid methods
  this_invalid  = @__invalid_methods || Set.new
  other_invalid = other.instance_variable_get(:"@__invalid_methods") || Set.new
  result.instance_variable_set(:"@__invalid_methods", this_invalid + other_invalid)

  result
end
method_missing(name, *args, &block) click to toggle source

Capture all bad configuration calls and save them for an error message later during validation.

Calls superclass method
# File lib/vagrant/plugin/v2/config.rb, line 73
def method_missing(name, *args, &block)
  return super if @__finalized

  # There are a few scenarios where ruby will attempt to implicity
  # coerce a given object into a certain type. Configs can end up
  # in some of these scenarios when they're being shipped around in
  # callbacks with splats. If method_missing allows these methods to be
  # called but continues to return Config back, Ruby will raise a
  # TypeError. Doing the normal thing of raising NoMethodError allows
  # Config to behave normally as its being passed through splats.
  #
  # For a bit more detail and some keywords for further searching, see:
  # https://ruby-doc.org/core-2.7.2/doc/implicit_conversion_rdoc.html
  if [:to_hash, :to_ary].include?(name)
    return super
  end

  name = name.to_s
  name = name[0...-1] if name.end_with?("=")

  @__invalid_methods ||= Set.new
  @__invalid_methods.add(name)

  # Return the dummy object so that anything else works
  ::Vagrant::Config::V2::DummyConfig.new
end
set_options(options) click to toggle source

Allows setting options from a hash. By default this simply calls the ‘#{key}=` method on the config class with the value, which is the expected behavior most of the time.

This is expected to mutate itself.

@param [Hash] options A hash of options to set on this configuration

key.
# File lib/vagrant/plugin/v2/config.rb, line 108
def set_options(options)
  options.each do |key, value|
    send("#{key}=", value)
  end
end
to_json(*a) click to toggle source

Converts this configuration object to JSON.

# File lib/vagrant/plugin/v2/config.rb, line 115
def to_json(*a)
  instance_variables_hash.to_json(*a)
end
to_s() click to toggle source

A default to_s implementation.

# File lib/vagrant/plugin/v2/config.rb, line 120
def to_s
  self.class.to_s
end
validate(machine) click to toggle source

Called after the configuration is finalized and loaded to validate this object.

@param [Machine] machine Access to the machine that is being

validated.

@return [Hash]

# File lib/vagrant/plugin/v2/config.rb, line 138
def validate(machine)
  return { self.to_s => _detected_errors }
end