Alternative Loaders

Runner deployments utilize element, value and secret loaders for loading their configurations and key-value lookups, which are highly customizable

It is possible to define any number and type of new loaders with specialized configurations, and typical loaders deployed with Rierino are described in this section.

Loader configurations are predefined and automatically populated in a typical Rierino deployment. This section provides information for possibilities in setting up a completely isolated development or testing environment on a local machine.

Element Loaders

Element loaders are used for loading runner members (such as systems, handlers, states) from a source, defined by "rierino.config.loader.class" property.

NoopElementLoader

This loader (com.rierino.runner.loader.NoopElementLoader) uses only local properties file and does not load any additional elements from a source.

StateElementLoader

This loader (com.rierino.runner.loader.StateElementLoader) uses a state manager, for loading elements, with the following configuration parameters:

Setting	Definition	Example	Default
rierino.config.loader.state.manager	Fully qualified name of the state manager class	com.rierino.state.manager.MongoStateManager	-
rierino.config.loader.system.*	Parameters for loader state manager's system	db=devops	-
rierino.config.loader.runner.*	Parameters for the "runner" state manager	collection=runner	-
rierino.config.loader.element.*	Parameters for the "element" state manager	collection=element	-

Key-Value Loader

KV loaders are used for loading values and secrets that are injected into element parameters. Two types of KV loaders are used for runners:

Value Loaders

Value loaders are used to replace ${{VARIABLE}} parameters. The loader to be used is defined by the "rierino.value.loader.class" property.

Secret Loaders

Secret loaders are used to replace #{{VARIABLE}} parameters. The loader to be used is defined by the "rierino.secret.loader.class" property.

Loader Types

EnvironmentKVLoader

This loader (com.rierino.runner.loader.EnvironmentKVLoader) loads VARIABLE from system environment variables.

FileKVLoader

This loader (com.rierino.runner.loader.FileKVLoader) loads VARIABLE from a text file with two options based on "rierino.*.loader.singleDir" parameter:

• Single Directory: Reads from [root]/[key1.key2] file for VARIABLE=key1.key2

• Not a Single Directory: Reads from [root]/[key1]/[key2] file for VARIABLE=key1.key2

where [root] is defined by "rierino.*.loader.root" parameter.

PropertiesKVLoader

This loader(com.rierino.runner.loader.PropertiesKVLoader) loads VARIABLE from a which is defined by "rierino.*.loader.path" parameter. It also has a "rierino.*.loader.dynamic" parameter, which forces values to be looked up each time from the file when set to "true".

Certain runner elements support "ephemeral" parameters, which are refreshed each time the element is reconnected (e.g. after a database connection failure). These parameters are defined using $!{{VARIABLE}} and #!{{VARIABLE}}.

An additional convention exists for allowing use of environment variables for any value or secret, by adding a question mark before the variable name (e.g. #{{?VARIABLE}} or ${{?VARIABLE}}).