OpenSearch uses plugins to add new features. A plugin can be included in the distribution by default (as part of *modules* directory) or can be installed optionally from a plugin repository.
This change provides a separate space called *sandbox* inside OpenSearch for the community to easily experiment new ideas and innovate. Ideally, this is where an experimental feature will reside before it can be promoted to the *modules* directory. All the plugins in this module will only be included in the **snapshot distributions**. During assembling distributions, we will check if the following two conditions are met to include the sandbox modules,
* the distribution is a snapshot i.e. the build system property `build.snapshot` is set to true. We use this because it will prevent accidental bundling of these modules in a release distribution.
* the `enable.sandbox` system property is set to true. By default it is set to true. The purpose of adding this extra flag is that we can exclude the modules from snapshots if needed. For example, we may want to run performance tests on snapshots without the sandbox modules.
Signed-off-by: Rabi Panda <adnapibar@gmail.com>