diskimage-builder

History

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
..
extra-data.d	Move elements & lib relative to diskimage_builder package	2016-11-01 17:27:41 -07:00
post-install.d	Move elements & lib relative to diskimage_builder package	2016-11-01 17:27:41 -07:00
pre-install.d	Move elements & lib relative to diskimage_builder package	2016-11-01 17:27:41 -07:00
README.rst	Move elements & lib relative to diskimage_builder package	2016-11-01 17:27:41 -07:00

README.rst

====
pypi
====
Inject a PyPI mirror
====================

Use a custom PyPI mirror to build images. The default is to bind mount one from
~/.cache/image-create/pypi/mirror into the build environment as mirror URL
file:///tmp/pypi. The element temporarily overwrites /root/.pip.conf
and .pydistutils.cfg to use it.

When online, the official pypi.python.org pypi index is supplied as an
extra-url, so uncached dependencies will still be available. When offline, only
the mirror is used - be warned that a stale mirror will cause build failures.
To disable the pypi.python.org index without using --offline (e.g. when working
behind a corporate firewall that prohibits pypi.python.org) set
DIB\_NO\_PYPI\_PIP to any non-empty value.

To use an arbitrary mirror set DIB\_PYPI\_MIRROR\_URL=http[s]://somevalue/

Additional mirrors can be added by exporting DIB\_PYPI\_MIRROR\_URL\_1=... etc.
Only the one mirror can be used by easy-install, but since wheels need to be in
the first mirror to be used, the last listed mirror is used as the pydistutils
index. NB: The sort order for these variables is a simple string sort - if you
have more than 9 additional mirrors, some care will be needed.

You can also set the number of retries that occur on failure by setting the
DIB\_PIP\_RETRIES environment variable. If setting fallback pip mirrors you
typically want to set this to 0 to prevent the need to fail multiple times
before falling back.

A typical use of this element is thus:
export DIB\_PYPI\_MIRROR\_URL=http://site/pypi/Ubuntu-13.10
export DIB\_PYPI\_MIRROR\_URL\_1=http://site/pypi/
export DIB\_PYPI\_MIRROR\_URL\_2=file:///tmp/pypi
export DIB\_PIP\_RETRIES=0

[devpi-server](https://git.openstack.org/cgit/openstack-infra/pypi-mirro://pypi.python.org/pypi/devpi-server)
can be useful in making a partial PyPI mirror suitable for building images. For
instance:

 * pip install -U devpi

 * devpi-server quickstart

 * devpi use http://machinename:3141

* Re-export your variables to point at the new mirror:

    export DIB\_PYPI\_MIRROR\_URL=http://machinename:3141/
    unset DIB\_PYPI\__MIRROR\_URL\_1
    unset DIB\_PYPI\__MIRROR\_URL\_2

The next time packages are installed, they'll be cached on the local devpi
server; subsequent runs pointed at the same mirror will use the local cache if
the upstream can't be contacted.

Note that this process only has the server running temporarily; see
[Quickstart: Permanent install on
server/laptop](http://doc.devpi.net/latest/quickstart-server.html) guide from
the devpi developers for more information on a more permanent setup.