lorax-composer ============== :Authors: Brian C. Lane lorax-composer is an API server that is compatible with the Weldr project's bdcs-api REST protocol. More information on Weldr can be found `on the Weldr blog `_. The server runs as root, and communication with it is via a unix domain socket (``/run/weldr/api.socket`` by default). The directory and socket are owned by root:weldr so that any user in the weldr group can use the API to control lorax-composer. When starting the server it will check for the correct permissions and ownership of a pre-existing directory, or it will create a new one if it doesn't exist. The socket path and group owner's name can be changed from the cmdline by passing it the ``--socket`` and ``--group`` arguments. As of version 19.7.7 it will drop root privileges for the API thread. The queue and compose thread still runs as root because it needs to be able to mount/umount files and run Anaconda. Logs ---- Logs are stored under ``/var/log/lorax-composer/`` and include all console messages as well as extra debugging info and API requests. Quickstart ---------- 1. Create a ``weldr`` user and group by running ``useradd weldr`` 2. Remove any pre-existing socket directory with ``rm -rf /run/weldr/`` A new directory with correct permissions will be created the first time the server runs. 3. Either start it via systemd with ``systemctl start lorax-composer`` or run it directly with ``lorax-composer /path/to/blueprints/`` The ``/path/to/blueprints/`` is where the blueprint's git repo will be created, and all the blueprints created with the ``/api/v0/blueprints/new`` route will be stored. If there are blueprint ``.toml`` files in the top level of the directory they will be imported into the blueprint git storage. Composing Images ---------------- As of version 19.7.7 lorax-composer can create ``tar`` output images. You can use curl to start a compose like this:: curl --unix-socket /run/weldr/api.socket -X POST -H "Content-Type: application/json" -d '{"blueprint_name": "http-server", "compose_type": "tar", "branch": "master"}' http:///api/v0/compose And then monitor it by passing the returned build UUID to ``/compose/status/``. Version 19.7.10 adds support for ``live-iso`` and ``partitioned-disk`` Adding Output Types ------------------- livemedia-creator supports a large number of output types, and only some of these are currently available via lorax-composer. To add a new output type to lorax-composer a kickstart file needs to be added to ``./share/composer/``. The name of the kickstart is what will be used by the ``/compose/types`` route, and the ``compose_type`` field of the POST to start a compose. It also needs to have code added to the :py:func:`pylorax.api.compose.compose_args` function. The ``_MAP`` entry in this function defines what lorax-composer will pass to :py:func:`pylorax.installer.novirt_install` when it runs the compose. When the compose is finished the output files need to be copied out of the build directory (``/var/lib/lorax/composer/results//compose/``), :py:func:`pylorax.api.compose.move_compose_results` handles this for each type. You should move them instead of copying to save space. If the new output type does not have support in livemedia-creator it should be added there first. This will make the output available to the widest number of users. Example: Add partitioned disk support ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Partitioned disk support is something that livemedia-creator already supports via the ``--make-disk`` cmdline argument. To add this to lorax-composer it needs 3 things: * A ``partitioned-disk.ks`` file in ``./share/composer/`` * A new entry in the _MAP in :py:func:`pylorax.api.compose.compose_args` * Add a bit of code to :py:func:`pylorax.api.compose.move_compose_results` to move the disk image from the compose directory to the results directory. The ``partitioned-disk.ks`` is pretty similar to the example minimal kickstart in ``./docs/rhel7-minimal.ks``. You should remove the ``url`` and ``repo`` commands, they will be added by the compose process. Make sure the bootloader packages are included in the ``%packages`` section at the end of the kickstart, and you will want to leave off the ``%end`` so that the compose can append the list of packages from the blueprint. The new ``_MAP`` entry should be a copy of one of the existing entries, but with ``make_disk`` set to ``True``. Make sure that none of the other ``make_*`` options are ``True``. The ``image_name`` is what the name of the final image will be. ``move_compose_results()`` can be as simple as moving the output file into the results directory, or it could do some post-processing on it. The end of the function should always clean up the ``./compose/`` directory, removing any unneeded extra files. This is especially true for the ``live-iso`` since it produces the contents of the iso as well as the boot.iso itself.