Merge "Deprecate syslinux"

doc/source/install/configure-pxe.rst

@@ -169,71 +169,6 @@ the PXE UEFI environment.
     for them. Please check :doc:`../admin/drivers` for information on whether
     your driver requires manual UEFI configuration.
 
-
-Legacy BIOS - Syslinux setup
-----------------------------
-
-In order to deploy instances with PXE on bare metal using Legacy BIOS boot
-mode, perform these additional steps on the ironic conductor node.
-
-#. Install the syslinux package with the PXE boot images:
-
-   Ubuntu (16.04LTS and later)::
-
-       sudo apt-get install syslinux-common pxelinux
-
-   RHEL8/CentOS8/Fedora::
-
-       sudo dnf install syslinux-tftpboot
-
-   SUSE::
-
-       sudo zypper install syslinux
-
-#. Copy the PXE image to ``/tftpboot``. The PXE image might be found at [1]_:
-
-   Ubuntu (16.04LTS and later)::
-
-       sudo cp /usr/lib/PXELINUX/pxelinux.0 /tftpboot
-
-   RHEL8/CentOS8/SUSE::
-
-       sudo cp /usr/share/syslinux/pxelinux.0 /tftpboot
-
-#. If whole disk images need to be deployed via PXE-netboot, copy the
-   chain.c32 image to ``/tftpboot`` to support it:
-
-   Ubuntu (16.04LTS and later)::
-
-       sudo cp /usr/lib/syslinux/modules/bios/chain.c32 /tftpboot
-
-   Fedora::
-
-       sudo cp /boot/extlinux/chain.c32 /tftpboot
-
-   RHEL8/CentOS8/SUSE::
-
-       sudo cp /usr/share/syslinux/chain.c32 /tftpboot/
-
-#. If the version of syslinux is **greater than** 4 we also need to make sure
-   that we copy the library modules into the ``/tftpboot`` directory [2]_
-   [1]_. For example, for Ubuntu run::
-
-       sudo cp /usr/lib/syslinux/modules/*/ldlinux.* /tftpboot
-
-#. Update the bare metal node with ``boot_mode:bios`` capability in
-   node's properties field. See :ref:`boot_mode_support` for details.
-
-#. Make sure that bare metal node is configured to boot in Legacy BIOS boot mode
-   and boot device is set to network/pxe.
-
-.. [1] On **Fedora/RHEL** the ``syslinux-tftpboot`` package already installs
-       the library modules and PXE image at ``/tftpboot``. If the TFTP server
-       is configured to listen to a different directory you should copy the
-       contents of ``/tftpboot`` to the configured directory
-.. [2] http://www.syslinux.org/wiki/index.php/Library_modules
-
-
 iPXE setup
 ----------
 
@@ -438,18 +373,18 @@ instead.
 
 In the following example, since 'x86' and 'x86_64' keys are not in the
 ``pxe_bootfile_name_by_arch`` or ``pxe_config_template_by_arch`` options, x86
-and x86_64 nodes will be deployed by 'pxelinux.0' or 'bootx64.efi', depending
+and x86_64 nodes will be deployed by 'undionly.kpxe' or 'bootx64.efi', depending
 on the node's ``boot_mode`` capability ('bios' or 'uefi'). However, aarch64
 nodes will be deployed by 'grubaa64.efi', and ppc64 nodes by 'bootppc64'::
 
     [pxe]
 
     # Bootfile DHCP parameter. (string value)
-    pxe_bootfile_name=pxelinux.0
+    pxe_bootfile_name=undionly.kpxe
 
     # On ironic-conductor node, template file for PXE
     # configuration. (string value)
-    pxe_config_template = $pybasedir/drivers/modules/pxe_config.template
+    pxe_config_template = $pybasedir/drivers/modules/ipxe_config.template
 
     # Bootfile DHCP parameter for UEFI boot mode. (string value)
     uefi_pxe_bootfile_name=bootx64.efi
@@ -478,6 +413,12 @@ nodes will be deployed by 'grubaa64.efi', and ppc64 nodes by 'bootppc64'::
    iPXE based deployment, and defaults to the same behavior as the comperable
    ``[pxe]pxe_bootfile_by_arch`` setting for standard PXE.
 
+.. note::
+   When booting PowerPC based machines, the firmware loader directly boots
+   a kernel and ramdisk. It explicitly reads a "pxelinux" style template,
+   and then directly retrieves the files defined in the file without a
+   "network boot program".
+
 PXE timeouts tuning
 -------------------
 

doc/source/user/architecture.rst

@@ -83,8 +83,8 @@ through the steps involved during the provisioning of a bare metal instance.
 These pre-requisites must be met before the deployment process:
 
 * Dependent packages to be configured on the Bare Metal service node(s)
-  where ironic-conductor is running like tftp-server, ipmi, syslinux etc for
+  where ironic-conductor is running like tftp-server, ipmi, grub/ipxe, etc
-  bare metal provisioning.
+  for bare metal provisioning.
 * Nova must be configured to make use of the bare metal service endpoint
   and compute driver should be configured to use ironic driver on the Nova
   compute node(s).

releasenotes/notes/deprecate-syslinux-support-98d327c67607fc8e.yaml

@@ -0,0 +1,26 @@
+---
+deprecations:
+  - |
+    Support for the `syslinux <https://wiki.syslinux.org/wiki/index.php?title=Syslinux_6_Changelog#Changes_in_6.04>`_
+    and the often separately package `isolinux <https://wiki.syslinux.org/wiki/index.php?title=ISOLINUX>`_
+    and `pxelinux <https://wiki.syslinux.org/wiki/index.php?title=PXELINUX>`_.
+    Legacy BIOS boot loaders, is deprecated and will be removed the future.
+    This is for two reasons. The first is because it is a BIOS mode bootloader,
+    and the shift to UEFI booting has reduced the need for these packages.
+    The second reason is a lack of maintenance, which is ultimately the same
+    reason Linux distributions are discussing dropping support and packaging.
+    Syslinux has not been updated since `2019 <https://repo.or.cz/syslinux.git/shortlog>`_.
+    Incidently, the file format it utilizes *is* supported by Power hardware,
+    and that may result in the configuration template remaining in Ironic for
+    the forseeable future.
+  - Support for use of `pxelinux <https://wiki.syslinux.org/wiki/index.php?title=PXELINUX>`_
+    is deprecated due to the deprecation of support for Syslinux.
+  - Support for virtual media booting with x86 Hardware in Legacy BIOS mode is
+    deprecated due to the dependency upon
+    `isolinux <https://wiki.syslinux.org/wiki/index.php?title=ISOLINUX>`_
+    for use of Legacy BIOS boot mode. ``isolinux`` is from the ``syslinux``
+    package and source tree.
+  - Deprecation of ``pxelinux``, as a result of the deprecation of ``syslinux``,
+    does ultimately mean the default for the ``pxe`` boot_interface to carry
+    defaults for the use of grub based network booting, specifically for
+    for operators who are unable to use iPXE.