diskimage-builder/diskimage_builder/elements/ubuntu-minimal/README.rst
Ian Wienand 97c01e48ed Move elements & lib relative to diskimage_builder package
Currently we have all our elements and library files in a top-level
directory and install them into
<root>/share/diskimage-builder/[elements|lib] (where root is either /
or the root of a virtualenv).

The problem with this is that editable/development installs (pip -e)
do *not* install data_files.  Thus we have no canonical location to
look for elements -- leading to the various odd things we do such as a
whole bunch of guessing at the top of disk-image-create and having a
special test-loader in tests/test_elements.py so we can run python
unit tests on those elements that have it.

data_files is really the wrong thing to use for what are essentially
assets of the program.  data_files install works well for things like
config-files, init.d files or dropping documentation files.

By moving the elements under the diskimage_builder package, we always
know where they are relative to where we import from.  In fact,
pkg_resources has an api for this which we wrap in the new
diskimage_builder/paths.py helper [1].

We use this helper to find the correct path in the couple of places we
need to find the base-elements dir, and for the paths to import the
library shell functions.

Elements such as svc-map and pkg-map include python unit-tests, which
we do not need tests/test_elements.py to special-case load any more.
They just get found automatically by the normal subunit loader.

I have a follow-on change (I69ca3d26fede0506a6353c077c69f735c8d84d28)
to move disk-image-create to a regular python entry-point.

Unfortunately, this has to move to work with setuptools.  You'd think
a symlink under diskimage_builder/[elements|lib] would work, but it
doesn't.

[1] this API handles stuff like getting files out of .zip archive
modules, which we don't do.  Essentially for us it's returning
__file__.

Change-Id: I5e3e3c97f385b1a4ff2031a161a55b231895df5b
2016-11-01 17:27:41 -07:00

1.3 KiB

ubuntu-minimal

Note: The ubuntu element is likely what you want unless you really know you want this one for some reason. The ubuntu element gets a lot more testing coverage and use.

Create a minimal image based on Ubuntu. We default to trusty but DIB_RELEASE is mapped to any series of Ubuntu.

If necessary, a custom apt keyring and debootstrap script can be supplied to the debootstrap command via DIB_APT_KEYRING and DIB_DEBIAN_DEBOOTSTRAP_SCRIPT respectively. Both options require the use of absolute rather than relative paths.

Use of this element will also require the tool 'debootstrap' to be available on your system. It should be available on Ubuntu, Debian, and Fedora.

The DIB_OFFLINE or more specific DIB_DEBIAN_USE_DEBOOTSTRAP_CACHE variables can be set to prefer the use of a pre-cached root filesystem tarball.

The DIB_DEBOOTSTRAP_EXTRA_ARGS environment variable may be used to pass extra arguments to the debootstrap command used to create the base filesystem image. If --keyring is is used in DIB_DEBOOTSTRAP_EXTRA_ARGS, it will override DIB_APT_KEYRING if that is used as well.

For further information about DIB_DEBIAN_DEBOOTSTRAP_SCRIPT, DIB_DEBIAN_USE_DEBOOTSTRAP_CACHE and DIB_DEBOOTSTRAP_EXTRA_ARGS please consult "README.rst" of the debootstrap element.