Module | Hiera::Backend |
In: |
lib/hiera/backend/yaml_backend.rb
lib/hiera/backend.rb |
Data lives in /var/lib/hiera by default. If a backend supplies a datadir in the config it will be used and subject to variable expansion based on scope
Finds the path to a datafile based on the Backend#datadir and extension
If the file is not found nil is returned
Constructs a list of data sources to search
If you give it a specific hierarchy it will just use that else it will use the global configured one, failing that it will just look in the ‘common’ data source.
An override can be supplied that will be pre-pended to the hierarchy.
The source names will be subject to variable expansion based on scope
Calls out to all configured backends in the order they were specified. The first one to answer will win.
This lets you declare multiple backends, a possible use case might be in Puppet where a Puppet module declares default data using in-module data while users can override using JSON/YAML etc. By layering the backends and putting the Puppet one last you can override module author data easily.
Backend instances are cached so if you need to connect to any databases then do so in your constructor, future calls to your backend will not create new instances
Parses a answer received from data files
Ultimately it just pass the data through parse_string but it makes some effort to handle arrays of strings as well
Parse a string like ’%{foo}’ against a supplied scope and additional scope. If either scope or extra_scope includes the varaible ‘foo’ it will be replaced else an empty string will be placed.
If both scope and extra_data has "foo" scope will win. See hiera-puppet for an example of this to make hiera aware of additional non scope variables