Robert Collins 4319730357 Add a ramdisk-install.d hook path.
We need to be able to do install.d like things for ramdisks
themselves, but install.d runs outside the ramdisk context - and its
likely to break peoples brains if we mangle the two together - so this
adds a new hook point, ramdisk-install, specifically for installing
things into the ramdisk.

Change-Id: I37d1660309cda6e28bd0b316b08f61db4e080613
2014-07-16 19:23:50 +12:00
..
2014-06-04 14:17:22 +01:00

This is the ramdisk element.

Almost any user building a ramdisk will want to include this in their build, as it triggers many of the vital functionality from the basic diskimage-builder libraries (such as init script aggregation, busybox population, etc).

An example of when one might want to use this toolchain to build a ramdisk would be the initial deployment of baremetal nodes in a TripleO setup. Various tools and scripts need to be injected into a ramdisk that will fetch and apply a machine image to local disks. That tooling/scripting customisation can be easily applied in a repeatable and automatable way, using this element.

NOTE: ramdisks require 1GB minimum memory on the machines they are booting.

See the top-level README.md of the project, for more information about the mechanisms available to a ramdisk element.