Developer Installation ====================== Note that for non-development use you can use distribution packages or install the latest release via ``pip`` in a ``virtualenv``. For development purposes, you can use ``pip -e`` to install the latest git tree checkout into a local development/testing ``virtualenv``, or use ``tox -e venv -- disk-image-create`` to run within a ``tox`` created environment. For example, to create a ``virtualenv`` and install :: $ mkdir dib $ cd dib $ virtualenv env $ source env/bin/activate $ git clone https://git.openstack.org/openstack/diskimage-builder $ cd diskimage-builder $ pip install -e . Invocation ========== The scripts can generally just be run. Options can be set on the command line or by exporting variables to override those present in lib/img-defaults. -h to get help. The image building scripts expect to be able to invoke commands with sudo, so if you want them to run non-interactively, you should either run them as root, with sudo -E, or allow your build user to run any sudo command without password. The variable ``ELEMENTS_PATH`` is a colon (:) separated path list to search for elements. The included ``elements`` tree is used when no path is supplied and is always added to the end of the path if a path is supplied. Earlier elements will override later elements, i.e. with ``ELEMENTS_PATH=foo:bar`` the element ``my-element`` will be chosen from ``foo/my-element`` over ``bar/my-element``, or any in-built element of the same name. By default, the image building scripts will not overwrite existing disk images, allowing you to compare the newly built image with the existing one. To change that behaviour, set the variable ``OVERWRITE_OLD_IMAGE`` to any value that isn't ``0``. If this value is zero then any existing image will be moved before the new image is written to the destination. Setting the variable ``DIB_SHOW_IMAGE_USAGE`` will print out a summarised disk-usage report for the final image of files and directories over 10MiB in size. Setting ``DIB_SHOW_IMAGE_USAGE_FULL`` will show all files and directories. These settings can be useful additions to the logs in automated build situations where debugging image-growth may be important.