BagConfig

This cookbook provides helper methods to Recipe instances allowing them to easily
provide configurations from data bag entries, and elegantly fall back to node
attributes if the data bag entry does not exist or the attribute requested does
not exist within the data bag entry.

By default, no attribute modification will be required when providing configuration
to a recipe via data bag entries. The Basic Usage section will cover this simple
usage. The Advanced Usage section will cover available configuration attributes
to handle non-standard naming and extra data bag functionality.

Basic Usage

Recipes

Recipes must make use of the #bag_or_node method(s) for data bag configuration to
be applied. For example, below is a generic recipe:

# recipes/default.rb

template node[:test][:my_file] do
  ...
end

To provide support for data bag configuration, the recipe can be modifed like so:

# recipes/default.rb

template bag_or_node(:my_file) do
  ...
end

This allows the value to come from the configuration data bag if it exists and
the value has been set there, other wise it will fall back to the value defined
by node[:test][:my_file].

Naming scheme

Data bags

The name of the data bag used will correspond to the name of the cookbook the
recipe resides within. For example, if the cookbook is named test, configuration
entries will be searched for within the test data bag. Configuration entries
for a node are based on the node name. If the name of the node is test1.box,
then the test data bag will be searched for an entry with the id of config_test1_box.

Quick Ref:

cookbook: test
node name: test1.box
data bag entry: test/config_test1_box

Advanced Usage

Custom Data Bag

If the configuration entries are not within a data bag that corresponds to the
cookbook name (or #node_key if it has been overriden) it can be explicitly defined
via attribute:

• node[cookbook][:config_data_bag_override] = 'my_custom_bag'

This will force config entries to be searched for within the my_custom_bag data bag.

Custom Data Bag Entry

By default, the configuration entries are based on the current node name, prefixed
with config_. If a custom entry name is required:

• node[cookbook][:config_bag] = 'myconfigentry'

This will force the data bag entry searched for to have the id myconfigentry.

Encrypted Data Bag Entry

Encrypted data bags are supported when the encrypted attribute is set:

• node[cookbook][:config_bag][:encrypted] = true

This will require the secret being provided either inline:

• node[cookbook][:config_bag][:secret] = 'my_secret'

or as a path to the secret file on the node:

• node[cookbook][:config_bag][:secret] = '/etc/config_secret.file'

Note: If a custom data bag entry name is required, it can be supplied via the
:name key:

• node[cookbook][:config_bag][:name] = 'myconfigentry'

Advanced Recipe Usage

This section is for helpers and configurations available to recipes providing
data bag based configuration.

Accessing configuration attributes

To access a single attribute:

file_name = bag_or_node(:file_name)

To access a number of attributes:

config_hash = bag_or_node_args(:file_name, :file_mode, :etc...)
...
config_hash[:file_name]

The latter provides an easy way to fetch all configuration attributes at the
start of the recipe and use the provided hash to access the values throughout
the recipe.

Note: The resulting hash keys will be symbolized regardless of how they are
initially provided to the method.

Non-standard attributes key

If the key used to access attributes on the node is not the same as the cookbook
name of the recipe, it can be overriden in the recipe by calling #override_node_key.

override_node_key('my-test')

Non-standard data bag

A custom data bag can be defined by recipe. Please note that if this approach is
taken (rather than overriding via attributes) it must be done in all applicable
recipes:

override_data_bag('my_bag')