linuxrc: Add gk.userinteraction.disabled

When this option is set and enabled, genkernel initramfs will not prompt
on errors, i.e. this will disable any user interaction, e.g. for a kiosk system.

Bug: https://bugs.gentoo.org/730966
Signed-off-by: Thomas Deutschmann <whissi@gentoo.org>

4 files changed, 69 insertions, 0 deletions

diff --git a/defaults/initrd.defaults b/defaults/initrd.defaults
index 15326dd2..79d7322c 100644
--- a/defaults/initrd.defaults
+++ b/defaults/initrd.defaults
@@ -96,6 +96,7 @@ GK_SSHD_LOCKFILE='/tmp/remote-rescueshell.lock'
 GK_SSHD_PIDFILE='/var/run/dropbear.pid'
 GK_SSHD_PORT=22
 GK_SSHD_WAIT=
+GK_USERINTERACTION_DISABLED_STATEFILE='/tmp/user-interaction.disabled'
 
 CRYPT_ENV_FILE='/etc/CRYPT_ENV.conf'
 CRYPT_KEYFILE_ROOT='/tmp/root.key'
diff --git a/defaults/initrd.scripts b/defaults/initrd.scripts
index d5378b7b..6dc588f7 100644
--- a/defaults/initrd.scripts
+++ b/defaults/initrd.scripts
@@ -959,6 +959,12 @@ run() {
 }
 
 run_shell() {
+	if [ -f "${GK_USERINTERACTION_DISABLED_STATEFILE}" ]
+	then
+		bad_msg "gk.userinteraction.disabled is set; Spawning a shell is disabled!"
+		return
+	fi
+
 	[ -x /bin/sh ] && SH=/bin/sh || SH=/bin/ash
 
 	run touch "${GK_SHELL_LOCKFILE}"
@@ -1114,6 +1120,15 @@ warn_msg() {
 	[ "$2" != '1' ] && printf "%b\n" "${WARN}**${NORMAL}${BOLD} ${msg_string} ${NORMAL}"
 }
 
+warn_msg_n() {
+	local msg_string=${1}
+	msg_string="${msg_string:-...}"
+
+	log_msg "[**] ${msg_string}"
+
+	[ "$2" != '1' ] && printf "%b" "${WARN}**${NORMAL}${BOLD} ${msg_string}"
+}
+
 write_env_file() {
 	local env_file=${1}
 	shift
@@ -1233,6 +1248,43 @@ prompt_user() {
 	[ -n "${3}" ] && local explnt=" or : ${3}" || local explnt="."
 
 	bad_msg "Could not find the ${2} in ${oldvalue}${explnt}"
+
+	if [ -f "${GK_USERINTERACTION_DISABLED_STATEFILE}" ]
+	then
+		bad_msg "gk.userinteraction.disabled is set; No user interaction allowed!"
+
+		wait_sshd
+
+		if [ -f "${GK_SSHD_LOCKFILE}" ]
+		then
+			warn_msg "The lockfile at '${GK_SSHD_LOCKFILE}' exists."
+			warn_msg "The boot process will be paused until the lock is removed."
+			while true
+			do
+				if [ -f "${GK_SSHD_LOCKFILE}" ]
+				then
+					sleep 1
+				else
+					break
+				fi
+			done
+		fi
+
+		local timeout=${GK_PROMPT_TIMEOUT}
+		[ ${timeout} -eq 0 ] && timeout=10
+
+		warn_msg_n "System will automatically reboot in ${timeout} seconds ..."
+		while [ ${timeout} -gt 0 ]
+		do
+			let timeout=${timeout}-1
+			sleep 1
+			printf "."
+		done
+		echo
+
+		reboot -f
+	fi
+
 	bad_msg "Please specify another value or:"
 	bad_msg "- press Enter for the same"
 	bad_msg '- type "shell" for a shell'
diff --git a/defaults/linuxrc b/defaults/linuxrc
index 682f6470..5354d09b 100644
--- a/defaults/linuxrc
+++ b/defaults/linuxrc
@@ -356,6 +356,14 @@ do
 			fi
 			unset tmp_wait
 		;;
+		gk.userinteraction.disabled=*)
+			tmp_disabled=${x#*=}
+			if is_true "${tmp_disabled}"
+			then
+				touch "${GK_USERINTERACTION_DISABLED_STATEFILE}"
+			fi
+			unset tmp_disabled
+		;;
 		gk.prompt.timeout=*)
 			tmp_timeout=${x#*=}
 			if is_int "${tmp_timeout}"
diff --git a/doc/genkernel.8.txt b/doc/genkernel.8.txt
index 5b15a021..f84892c4 100644
--- a/doc/genkernel.8.txt
+++ b/doc/genkernel.8.txt
@@ -835,6 +835,14 @@ genkernel's initramfs will only mount root filesystem by default. If you
 want to store the log file in '/var/log/genkernel-boot.log' for example
 make sure that this mountpoint is accessible, see *initramfs.mounts*.
 
+*gk.userinteraction.disabled*=<...>::
+By default, genkernel will prompt on errors. In case this is not wanted
+or desired, e.g. for a kiosk system, this boolean option will disable
+any prompting, including the rescue shell.
+
+NOTE: Because no user interaction is possible when this option is set,
+system will automatically reboot on error after a timeout.
+
 *noload*=<...>::
     List of modules to skip loading.
     Separate using commas or spaces.