Configuration of instance creation
----------------------------------
+Note: the minimum disk size accepted is 256MB, as ``debootstrap``
+requires disk space both for downloading the packages and installing
+them.
+
The kind of instance created can be customized via a settings file. This
file is not installed by default, as the instance creation will work
without it. The creation scripts will look for it in
-``$sysconfdir/defaults/ganeti-instance-debootstrap``, so if you have run
+``$sysconfdir/default/ganeti-instance-debootstrap``, so if you have run
configure with the parameter ``--sysconfdir=/etc``, the final filename
-will be ``/etc/defaults/ganeti-instance-debootstrap``.
+will be ``/etc/default/ganeti-instance-debootstrap``.
The following settings will be examined in this file (see also the file
named 'defaults' in the source distribution for more details):
+- PROXY: http proxy to use for non-cached installs
- MIRROR: the mirror to use if not the default one
- ARCH: either i386 or amd64, otherwise your current architecture will
be used
- SUITE: the actual OS to be installed; the current default is Debian
- *lenny*, and you can choose any of the OSes supported deboostrap (on
+ *wheezy*, and you can choose any of the OSes supported deboostrap (on
Debian, look into /usr/share/deboostrap/scripts)
- EXTRAPKGS: most OSes will need some extra packages installed to make
them work nicely under Xen; the example file containts a few
suggestions
+- COMPONENTS: if defined, overrides the default debootstrap components
+ ("main"); this can be helpful e.g. by using "main,contrib,nonfree" for
+ Debian, or "main,universe" for Ubuntu
+- CUSTOMIZE_DIR: a directory containing customization script for the
+ instance. (by default $sysconfdir/ganeti/instance-debootstrap/hooks)
+ See "Customization of the instance" below.
- GENERATE_CACHE: if 'yes' (the default), the installation process will
save and reuse a cache file to speed reinstalls (located under
$localstatedir/cache/ganeti-instance-debootstrap)
otherwise, the value of this variable will be taken as the number of
days after which to remove the cache file; the default is 14 (two
weeks)
+- PARTITION_STYLE: if 'none' the device will be formatted directly, if 'msdos'
+ a partition table will be installed on it. You need to have kpartx installed
+ to use the 'msdos' option. The default is 'msdos' from Ganeti 2.0 onwards,
+ but still 'none' if installing under Ganeti 1.2
Note that the settings file is important on the node that the instance
is installed on, not the cluster master. This is indeed not a very good
model of using this OS but currently the OS interface in ganeti is
limiting.
+Creating OS variants
+--------------------
+
+Every Ganeti OS supports variants, so it's possible to define custom OS
+variants with instance-debootstrap as well. First, an additional variant has
+to be defined in ``$osdir/debootstrap/variants.list`` (with ``$osdir`` being
+``/usr/share/ganeti/os`` by default). Secondly, you can configure this
+instance variant in
+``$sysconfdir/ganeti/instance-debootstrap/variants/$variant.conf``, overriding
+the settings mentioned in the previous section.
+
+To use the newly created instance variant, specify it in ``gnt-instance`` like
+this::
+
+ gnt-instance add -o debootstrap+precise ...
+
+Example
++++++++
+
+To create a Ubuntu 12.04 (precise) instance variant, add the following to
+``$osdir/debootstrap/variants.list``::
+
+ precise
+
+Now create the file
+``$sysconfdir/ganeti/instance-debootstrap/variants/precise.conf`` with the
+following content::
+
+ MIRROR="http://archive.ubuntu.com/ubuntu/"
+ SUITE="precise"
+ COMPONENTS="main,universe"
+ ARCH="amd64"
+
+You can create Ubuntu 12.04 instances as follows::
+
+ gnt-instance add -t plain -o debootstrap+precise --disk 0:size=10000m -n node1.example.com instance1.example.com
+
+For this to work, make sure that you have the appropriate debootstrap script
+for precise (or just create a symlink called ``precise`` to ``gutsy`` in
+``/usr/share/debootstrap/scripts``).
+
+Instance creation parameters
+----------------------------
+
+Some aspects of the created instance can be conrolled via parameters at
+instance creation time with the ``-O`` parameter of ``gnt-instance``.
+
+The supported parameters are:
+
+- filesystem: the filesystem type to use for the root partition. This has to
+ be a filesystem type supported by ``mke2fs``. The default is 'ext4'.
+
+Customization of the instance
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+If run-parts is in the os create script, and the CUSTOMIZE_DIR (by
+default $sysconfdir/ganeti/instance-debootstrap/hooks,
+/etc/ganeti/instance-debootstrap/hooks if you configured the os with
+--sysconfdir=/etc) directory exists any executable whose name matches
+the run-parts execution rules (quoting run-parts(8): the names must
+consist entirely of upper and lower case letters, digits, underscores,
+and hyphens) is executed to allow further personalization of the
+installation. The following environment variables are passed, in
+addition to the ones ganeti passes to the OS scripts:
+
+TARGET: directory in which the filesystem is mounted
+SUITE: suite installed by debootstrap (eg: wheezy)
+ARCH: target architecture
+PARTITION_STYLE: style of the disk partitioning (see above)
+EXTRA_PKGS: extra packages installed by debootstrap
+BLOCKDEV: ganeti block device
+FSYSDEV: device in which the filesystem resides (the one mounted in TARGET)
+
+The scripts in CUSTOMIZE_DIR can exit with an error code to signal an error in
+the instance creation, should they fail.
+
+The scripts in CUSTOMIZE_DIR should not start any long-term processes or
+daemons using this directory, otherwise the installation will fail because it
+won't be able to umount the filesystem from the directory, and hand the
+instance back to Ganeti.
+
+Example
++++++++
+
+The root password can be automatically set when the instance is created. In
+order to do this, the ``examples/hooks/defaultpasswords`` file has to be copied
+to ``$sysconfdir/ganeti/instance-debootstrap/hooks/``, and its data file
+``examples/hooks/confdata/defaultpasswords`` has to be copied to
+``$sysconfdir/ganeti/instance-debootstrap/hooks/confdata/`` and modified
+accordingly to one's own need. The file syntax is such that each line represent
+a user, with the format::
+
+ username:password
+
+After copying the two files, just running the instance creation as usual will
+automatically cause their execution.
+
Caching
~~~~~~~
definitions to /etc/network/interfaces
- after configuring the network, it is recommended to run ``apt-get
update`` so that signatures for the release files are picked up
+
+.. vim: set textwidth=72 :
+.. Local Variables:
+.. mode: rst
+.. fill-column: 72
+.. End:
projects / ext/instance-debootstrap.git / blobdiff