From f6a2452d4c72d52af1abd6f9d4165ff19a0506ba Mon Sep 17 00:00:00 2001
From: Ian Wienand <iwienand@redhat.com>
Date: Wed, 12 Sep 2018 17:07:19 +1000
Subject: [PATCH] Only append DIB_BOOTLOADER_DEFAULT_CMDLINE to default grub
 entry

The grub.cfg has two variables [1]

 GRUB_CMDLINE_LINUX : used on all boots
 GRUB_CMDLINE_LINUX_DEFAULT : additionally used on all "normal" boots

The problem with I2298675dda1f699c572b3423e7274bc8bd7c1c9d is that it
appened the values in DIB_BOOTLOADER_DEFAULT_CMDLINE to both of these,
resulting in duplicated arguments.  I don't think we considered that
GRUB_CMDLINE_LINUX_DEFAULT actually already appends to the
GRUB_CMDLINE_LINUX values.

Make DIB_BOOTLOADER_DEFAULT_CMDLINE only append itself to
GRUB_CMDLINE_LINUX_DEFAULT.  That seems to line up sensibly with the
name of the variable.

Documentation is enhanced around this, and a releasenote added.

[1] https://help.ubuntu.com/community/Grub2/Setup

Change-Id: I76b5442a9090c19a6540ed2d4ab324546f241ebf
Closes: #1791736
---
 diskimage_builder/elements/bootloader/README.rst           | 6 +++---
 .../elements/bootloader/finalise.d/50-bootloader           | 3 +--
 .../notes/bootloader-commandline-d2db7524f1f9ad28.yaml     | 7 +++++++
 3 files changed, 11 insertions(+), 5 deletions(-)
 create mode 100644 releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml

diff --git a/diskimage_builder/elements/bootloader/README.rst b/diskimage_builder/elements/bootloader/README.rst
index ce2147bc..56e17076 100644
--- a/diskimage_builder/elements/bootloader/README.rst
+++ b/diskimage_builder/elements/bootloader/README.rst
@@ -13,6 +13,6 @@ Arguments
 * ``DIB_GRUB_TIMEOUT`` sets the ``grub`` menu timeout.  It defaults to
   5 seconds.  Set this to 0 (no timeout) for fast boot times.
 
-* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets the CMDLINE parameters that
-  are appended to the grub.cfg configuration. It defaults to
-  'nofb nomodeset vga=normal'
+* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets parameters that are appended
+  to the ``GRUB_CMDLINE_LINUX_DEFAULT`` values in ``grub.cfg``
+  configuration. It defaults to ``nofb nomodeset vga=normal``.
diff --git a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
index 0a6b0db6..75dfd78c 100755
--- a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
+++ b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
@@ -185,9 +185,8 @@ function install_grub2 {
 
     GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=${SERIAL_CONSOLE} no_timer_check"
 
-    echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT}\"" >>/etc/default/grub
+    echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT} ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"" >>/etc/default/grub
     echo 'GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"' >>/etc/default/grub
-    sed -i -e "s/\(^GRUB_CMDLINE_LINUX.*\)\"$/\1 ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"/" /etc/default/grub
 
     if type grub2-mkconfig >/dev/null; then
         GRUB_MKCONFIG="grub2-mkconfig -o $GRUB_CFG"
diff --git a/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
new file mode 100644
index 00000000..643d22b9
--- /dev/null
+++ b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
@@ -0,0 +1,7 @@
+---
+other:
+  - It has been clarified that the ``DIB_BOOTLOADER_DEFAULT_CMDLINE``
+    variable appends its values to grubs
+    ``GRUB_CMDLINE_LINUX_DEFAULT``, which is used during all normal
+    boots but not rescue boots; as opposed to applying to
+    ``GRUB_CMDLINE_LINUX``