Resources are stateful entities and persist across pipelines, enabling passing of information between pipelines. This is especially useful when creating a pipeline of pipelines.
Steps can store any key-value pair data in a resource using the
write_outpututility function. These values can then be referenced as environment variables by any subsequent cuting step that uses that resource as an input. Therefore, a step can pass information to another step in the run of the pipeline.
The environment variable for the stored value is of the form
res_<resource name>_<key name>.
The following example creates three properties in the resource
write_output myImage sport="baseball" equipment="bat" field="diamond"
When the resource is specified in a step's
inputResources, these properties can be accessed as the following environment variables:
$ printenv res_myImage_sport baseball $ printenv res_myImage_equipment bat $ printenv res_myImage_field diamond
For more information, see Creating Stateful Pipelines.