The set of scripts in this directory is responsible for every step in the process of building a BOSH stemcell, regardless of target hypervisor or virtual machine format.
See bosh-stemcell
This section briefly outlines the different concepts used in the structure of the stemcell builder.
Every stage in the build process is placed in a different directory in
the stages/ directory. These stages are 100% isolated and cannot
express dependency to other stages other than by convention.
The code that is executed when a stage is executed is contained in the
file apply.sh in the root of the stage's directory.
Any assets that a stage may require to successfully execute should also
be placed in the stage's directory. By convention, this is the assets/
directory.
Stages may depend on external configuration to execute successfully.
Instead of configuring every stage independently, and in an ad-hoc
manner, a global configuration file can be seeded to every stage before
a build is started. This enables custom code in every stage to catch any
configuration errors early on, allowing the developer to correct these
errors without wasting time on a build that will fail. The code that is
responsible for taking in the seed configuration, and storing its own
configuration in its own path is config.sh. It is not necessary that
this file exists; stages without this file are assumed not to require
any configuration.