Force text mode console in base element.

Apply kernel command line parameters to force Linux to remain in text
mode. Typical distro kernels quickly switch into a graphical screenmode
and this is incompatible with common Lights Out Management hardware
which is able to intercept text mode consoles to display them remotely.

Change-Id: Id553972c4fd87e78c9e6fe344331a399913d965e

README.md

@@ -249,6 +249,15 @@ comma-delimited string. Some examples:
 * break=after-first-boot,before-pre-install will break after the first-boot
   hooks and before the pre-install hooks.
 
+Images are built such that the Linux kernel is instructed not to switch into
+graphical consoles (i.e. it will not activate KMS). This maximises
+compatibility with remote console interception hardware, such as HP's iLO.
+However, you will typicallly only see kernel messages on the console - init
+daemons (e.g. upstart) will usually be instructed to output to a serial
+console so nova's console-log command can function. There is an element in the
+tripleo-image-elements repository called "remove-serial-console" which will
+force all boot messages to appear on the main console.
+
 Testing Elements
 ----------------
 

elements/base/install.d/05-force-text-mode-console

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+set -e
+
+# If lsb_release is missing, just do nothing.
+DISTRO=`lsb_release -si` || true
+
+GRUBFILE=""
+
+case $DISTRO in
+  'Ubuntu'|'Debian')
+    sed -i -e 's/\(^GRUB_CMDLINE_LINUX.*\)"$/\1 nomodeset vga=normal"/' /etc/default/grub
+    ;;
+  'Fedora')
+    echo 'GRUB_CMDLINE_LINUX="nomodeset vga=normal"' >/etc/default/grub
+    sed -i -e 's/terminal_output gfxterm/terminal_output console/' /boot/grub2/grub.cfg
+    ;;
+esac
+
+echo 'GRUB_TERMINAL=console' >>/etc/default/grub
+