StealthOS/subiquity
StealthOS
/
subiquity
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

doc: many tutorial editorial improvements 

Co-authored-by: Sally <sally.makin@canonical.com>
This commit is contained in:
Dan Bungert 2023-07-07 09:56:22 -06:00 committed by Dan Bungert
parent 35bbd4db18
commit 1418af004f
1 changed files with 30 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

53
doc/tutorial/intro-to-autoinstall.rst
View File

@ -1,10 +1,10 @@
.. _tutorial_intro-to-autoinstall:
Introduction to Autoinstall
Introduction to autoinstall
***************************
Ubuntu installation automation is performed with the autoinstall format.
You might also know this feature as unattended or handsoff or preseeded
Automatic Ubuntu installation is performed with the autoinstall format.
You might also know this feature as "unattended", "hands-off" or "preseeded"
installation.
This format is supported in the following installers:
@ -23,35 +23,36 @@ Differences from debian-installer preseeding
(also known as d-i).
Autoinstalls differ from preseeds in the following ways:
* the format is different (yaml vs debconf-set-selections)
* when the answer to a question is not present in a preseed, d-i stops and
asks the user for input. Autoinstalls are not like this: by default, if
there is any autoinstall configuration at all, the installer takes the
default for any unanswered question (and fails if there is no default).
* You can designate particular sections in the configuration as "interactive",
which means the installer will still stop and ask about those.
* The format is different: autoinstalls use YAML instead of the preseed
debconf-set-selections
* When the answer to a question is not present in a preseed, d-i stops and
asks the user for input. By comparison, if there is any autoinstall
configuration at all, the autoinstall takes the default for any
unanswered question (and fails if there is no default).
* You can designate particular sections in the autoinstall configuration as
"interactive", which means the installer will still stop and ask about those.
Providing the autoinstall configuration
=======================================
There are 2 methods of providing the autoinstall configuration:
There are 2 ways to provide the autoinstall configuration:
* Carried as part of cloud-config
* Directly on the install media
Autoinstall by way of cloud-config
----------------------------------
The suggested method of providing autoinstall to the Ubuntu installer is by way
of cloud-init. This allows the configuration to be applied to the installer
The suggested way of providing autoinstall config to the Ubuntu installer is
via cloud-init. This allows the configuration to be applied to the installer
without having to modify the install media.
The autoinstall config is provided via cloud-init configuration, which is
almost endlessly flexible. In most scenarios the easiest way will be to provide
user-data via the :external+cloud-init:ref:`datasource_nocloud` data source.
user data via the :external+cloud-init:ref:`datasource_nocloud` data source.
When providing autoinstall via cloud-init, the autoinstall config is provided
as :external+cloud-init:ref:`user_data_formats-cloud_config`. This
as :external+cloud-init:ref:`user_data_formats-cloud_config`. This
means we need a :code:`#cloud-config` header. The autoinstall directives are
placed under a top level :code:`autoinstall` key, like so:
@ -62,6 +63,12 @@ placed under a top level :code:`autoinstall` key, like so:
version: 1
....
.. note::
:external+cloud-init:ref:`user_data_formats-cloud_config` files must contain
the ``#cloud-config`` header to be recognized as a valid cloud config data
file.
Autoinstall on the install media
--------------------------------
@ -69,17 +76,17 @@ Another option for supplying autoinstall to the Ubuntu installer is to place a
file named :code:`autoinstall.yaml` on the install media itself.
There are two potential locations for the :code:`autoinstall.yaml` file:
* At the root of the "cdrom". When writing the installation ISO to a USB
* At the root of the "cdrom". When you write the installation ISO to a USB
Flash Drive, this can be done by copying the :code:`autoinstall.yaml` to the
partition containing the contents of the ISO - i.e., in the same directory
containing the :code:`casper` directory.
partition containing the contents of the ISO - i.e.,
in the directory containing the ``casper`` sub-directory.
* On the rootfs of the installation system - this option will typically
require modifying the installation ISO and is not suggested, but is
supported.
Directly specifying autoinstall as a :code:`autoinstall.yaml` file does not
require a :code:`#cloud-config` header, and does not use a top level
:code:`autoinstall` key. The autoinstall directives are placed at the top
:code:`autoinstall` key. The autoinstall directives are placed at the top
level.
.. code-block:: yaml
@ -88,14 +95,14 @@ level.
....
Cloud-init and Autoinstall interaction
Cloud-init and autoinstall interaction
======================================
While cloud-init may assist in providing the autoinstall configuration to the
Ubuntu installer, cloud-init itself is not processing the autoinstall.
While cloud-init may provide the autoinstall configuration to the
Ubuntu installer, it does not process the autoinstall itself.
If cloud-init directives are intended to modify the ephemeral system, they
must appear at the top level of the cloud-config. If instead
must appear at the top level of the cloud-config. If instead
cloud-init directives are intended to modify the system being installed, they
must appear under a :code:`user-data` section in :code:`autoinstall`.