fluid-project/fluid-launcher

variables that are deeply nested in an options structure](http://yargs.js.org/docs/#api-reference-deep-key). For example, given the following configuration: ```json { "type": "launcherConfig", "options": { "gradeNames": ["my.launcher.worker"], "var1": { "var2": "set in the options file." } } } ``` You could launch the above configuration using `node examples/my-launcher.js --var1.var2 "Set from the command line."` ## Pulling Environment Variables by Reference As noted above, by default the launcher will merge options in a particular order (command line, then environment variables, then options file, then defaults). However, it is possible to "pull" an option from an earlier stage in the merge process. This can be useful if you need to load configuration from an options file, but want to use environment variables to set sensitive information like passwords and API keys. The following example shows how to "pull" a variable from the environment: ```json { "type": "launcherConfig", "options": { "gradeNames": ["my.launcher.worker"], "var1":