Install types permit elements to be installed from different sources, such as git repositories, distribution packages, or pip. The default install type is ‘source’ but it can be modified on the disk-image-create command line via the –install-type option. For example you can set:
to enable package installs by default. Alternately, you can also set DIB_DEFAULT_INSTALLTYPE.
Many elements expose different install types. The different implementations live under <install-dir-prefix>-<install-type>-install directories under an element’s install.d. The base element enables the chosen install type by symlinking the correct hook scripts under install.d directly. <install-dir-prefix> can be a string of alphanumeric and ‘-’ characters, but typically corresponds to the element name.
For example, the nova element would provide:
The following symlink would be created for the package install type:
install.d/74-nova -> nova-package-install/74-nova
Or, for the source install type:
install.d/74-nova -> nova-source-install/74-nova
All other scripts that exist under install.d for an element will be executed as normal. This allows common install code to live in a script under install.d.
To set the install type for an element define an environment variable DIB_INSTALLTYPE_<install_dir_prefx>. Note that if you used - characters in your install directory prefix, those need to be replaced with _ in the environment variable.
For example, to enable the package install type for the set of nova elements that use nova as the install type prefix, define the following: