+update-motd (1.12) jaunty; urgency=low
+
+ * Inotify support
+ - big thanks for Jon Bernard <jbernard@librato.com> for all his help!
+ * debian/dirs: add /etc/update-motd directory
+ * debian/install: install /etc/update-motd/iwatch.xml
+ * debian/iwatch.xml: iwatch configuration file
+ * debian/update-motd.cron.d: use the "d" argument for the 10-minute job
+ * update-motd:
+ - default FREQ to "d"
+ - default vars added for inotify
+ - usage statement updated accordingly
+ - ensure that the cronjobs are no-ops, if running in inotify mode
+ - handle starting/stopping inotify via --enable and --disable
+ - move the trap to the top, and make sure the lock is established
+ - do not run the /etc/update-motd.*/ scripts, if in inotify mode
+ * update-motd.1: documentation updated
+
+ -- Dustin Kirkland <kirkland@ubuntu.com> Thu, 05 Mar 2009 13:20:14 -0600
+
update-motd (1.11) jaunty; urgency=low
* update-motd: don't fail the entire script, if renice/ionice fail,
SKEL=/etc/motd.tail
REAL=/var/run/motd
DIR=/etc/$NAME.d
-FREQ=
+FREQ=d
DISABLED=/var/lib/$NAME/disabled
LASTRUN=/var/run/$NAME.lastrun
-FORCE=0
+INOTIFY_PID=/var/run/$NAME-inotify.pid
+INOTIFY_CONFIG=/etc/update-motd/iwatch.xml
+INOTIFY_DAEMON=/usr/bin/iwatch
if [ -f "$NEW" ]; then
# If /var/run/motd.new exists, another instance is running
exit 0
fi
+# Make sure we clean up the motd.new lock file if we exit for any reason
+touch "$NEW"
+trap "rm -f $NEW 2>/dev/null || true" EXIT HUP INT QUIT TERM
+
usage() {
echo "Usage:
update-motd [--disable|--enable|--force] [d|hourly|daily|weekly|monthly]
--disable - will prevent update-motd from running; useful for
- temporarily disabling automatic updates of /etc/motd
- by the /etc/cron.d/update-motd cronjob.
+ disabling automatic updates of /etc/motd by the
+ /etc/cron.d/update-motd cronjob or inotify daemon.
--enable - will allow update-motd to run; useful for enabling
automatic updates of /etc/motd through the
- /etc/cron.d/update-motd cronjob.
+ /etc/cron.d/update-motd cronjob or inotify daemon.
--force - will override a disabled update-motd for a single
update of /etc/motd.
d - will run the scripts in /etc/$NAME.d (Default)
daily - will run the scripts in /etc/$NAME.d/daily
weekly - will run the scripts in /etc/$NAME.d/weekly
monthly - will run the scripts in /etc/$NAME.d/monthly
+ inotify - will watch /var/run/$NAME, updating /etc/motd when a file
+ in that directory changes
" 1>&2
}
FORCE=0
+INOTIFY=0
+DISABLE=0
+ENABLE=0
for arg in $@; do
case $arg in
"--disable"|"-d")
- touch "$DISABLED"
- echo "$NAME is now disabled." 1>&2
- # Regenerate motd created at boot by
- # /etc/init.d/bootmisc.sh
- uname -snrvm > $REAL
- [ -f $SKEL ] && cat $SKEL >> $REAL
- exit 0
+ DISABLE=1
;;
"--enable"|"-e")
- rm -f "$DISABLED"
- echo "$NAME is now enabled." 1>&2
- # Do not exit here, as we want to update the MOTD
- # immediately upon enabling
+ ENABLE=1
;;
"--force"|"-f")
FORCE=1
;;
- "d")
- FREQ=
- ;;
- "hourly"|"daily"|"weekly"|"monthly")
+ "d"|"hourly"|"daily"|"weekly"|"monthly")
FREQ=$arg
;;
+ "inotify")
+ if [ ! -x "/usr/bin/iwatch" ]; then
+ echo "The program 'iwatch' is currently not installed. You can install it by typing:" 1>&2
+ echo "sudo apt-get install iwatch" 1>&2
+ exit 1
+ fi
+ INOTIFY=1
+ FREQ=
+ ;;
*)
usage
exit 1
;;
esac
done
+
+case "$FREQ" in
+ "d"|"hourly"|"daily"|"weekly"|"monthly")
+ if [ -n "$FREQ" -a -r "$INOTIFY_PID" -a "$DISABLE" = "0" -a "$ENABLE" = "0" ]; then
+ if ps `cat $INOTIFY_PID` >/dev/null 2>&1; then
+ # We're running in inotify mode, so exit immediately
+ # This no-ops the cron jobs!
+ exit 0
+ fi
+ fi
+ ;;
+ *)
+ ;;
+esac
+[ "$FREQ" = "d" ] && FREQ=
+
+if [ "$DISABLE" = "1" ]; then
+ if [ "$INOTIFY" = "1" ]; then
+ if [ -f "$INOTIFY_PID" ]; then
+ start-stop-daemon -K -p "$INOTIFY_PID"
+ echo "$NAME inotify daemon now stopped." 1>&2
+ rm -f "$INOTIFY_PID"
+ else
+ echo "$NAME inotify daemon not found." 1>&2
+ exit 1
+ fi
+ else
+ touch "$DISABLED" && echo "$NAME is now disabled." 1>&2
+ rc=$?
+ fi
+ # Regenerate motd created at boot by /etc/init.d/bootmisc.sh
+ uname -snrvm > $REAL
+ [ -f $SKEL ] && cat $SKEL >> $REAL
+ exit $rc
+fi
+
+if [ "$ENABLE" = "1" ]; then
+ rm -f "$DISABLED"
+ echo "$NAME is now enabled." 1>&2
+ # Do not exit here, as we want to update the MOTD
+ # immediately upon enabling
+ if [ "$INOTIFY" = "1" ]; then
+ if [ -f "$INOTIFY_PID" ]; then
+ echo "$NAME inotify daemon already running" 1>&2
+ exit 1
+ else
+ if [ ! -r "$INOTIFY_CONFIG" ]; then
+ echo "Error reading config file: $INOTIFY_CONFIG" 2>&1
+ exit 1
+ fi
+ if $INOTIFY_DAEMON -d -f $INOTIFY_CONFIG -p $INOTIFY_PID; then
+ echo "$NAME inotify daemon started." 1>&2
+ else
+ rc=$?
+ echo "Error starting $NAME inotify daemon." 1>&2
+ exit $rc
+
+ fi
+ fi
+ fi
+fi
+
DIR="$DIR/$FREQ"
if [ -f "$DISABLED" ] && [ "$FORCE" != "1" ]; then
exit 1
fi
-# Make sure we clean up the motd.new lock file if we exit for any reason
-trap "rm -f $NEW 2>/dev/null || true" EXIT HUP INT QUIT TERM
-
if [ "$FORCE" != "1" ]; then
# Be *really* nice, if we're running in the background (not forced)
# But don't fail the script if we're not able to 'nice'
# Create a directory to cache the script output across update-motd
# runs of different frequencies
mkdir -p "/var/run/$NAME"
-# Obtain a list of the current scripts "due" to run
-scripts=`run-parts --lsbsysinit --test $DIR`
-for script in $scripts; do
- file=`basename "$script"`
- # Run each script, writing to a cache file, of the same num-name
- # of the script executing
- $script > "/var/run/$NAME/$file" 2>/dev/null
-done
+
+# If we're not in inotify-mode, run each script
+if [ "$INOTIFY" = "0" ]; then
+ # Obtain a list of the current scripts "due" to run
+ scripts=`run-parts --lsbsysinit --test $DIR`
+ for script in $scripts; do
+ file=`basename "$script"`
+ # Run each script, writing to a cache file, of the same num-name
+ # of the script executing
+ $script > "/var/run/$NAME/$file" 2>/dev/null
+ done
+fi
+
# Now, concatenate ALL of the cached update-motd output, thus collecting
# ordered output across update-motd runs of different frequencies
for file in `ls /var/run/$NAME`; do
.IX Title "UPDATE-MOTD 1"
-.TH UPDATE-MOTD 1 "2008-11-11" update-motd update-motd
+.TH UPDATE-MOTD 1 "2009-03-05" update-motd update-motd
.SH "NAME"
update\-motd \- Automatically update the message-of-the-day (MOTD)
.SH "SYNOPSIS"
.IX Header "SYNOPSIS"
-update\-motd [\-\-disable|\-\-enable|\-\-force] [d|hourly|daily|weekly|monthly]
+update\-motd [\-\-disable|\-\-enable|\-\-force]
+ [d|hourly|daily|weekly|monthly|inotify]
.SH "OPTIONS"
.IX Header "OPTIONS"
.TP
\fB\-\-disable\fP
-Prevent update-motd from running. This is useful for temporarily disabling automatic updates of \fI/etc/motd\fP by the \fI/etc/cron.d/update-motd\fP cronjob. Note that this regenerates a base MOTD without the update-motd additions, and then exits.
+Prevent update-motd from running. This is useful for temporarily disabling automatic updates of \fI/etc/motd\fP by the \fI/etc/cron.d/update-motd\fP cronjob or the inotify daemon. Note that this regenerates a base MOTD without the update-motd additions, and then exits.
.TP
\fB\-\-enable\fP
-Allow update-motd to run. This is useful for enabling automatic updates of \fI/etc/motd\fP through the \fI/etc/cron.d/update-motd\fP cronjob. Note that this updates the MOTD immediately.
+Allow update-motd to run. This is useful for enabling automatic updates of \fI/etc/motd\fP through the \fI/etc/cron.d/update-motd\fP cronjob or inotify daemon. Note that this updates the MOTD immediately.
.TP
\fB\-\-force\fP
Override a disabled update-motd for a single, immediate update of \fI/etc/motd\fP.
.TP
\fBmonthly\fP
Runs the scripts in /etc/update-motd.d/monthly
+.TP
+\fBinotify\fP
+Watches /var/run/$NAME, updating /etc/motd when a file in that directory changes
+
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
-This script executes lists of scripts in lexical order, concatenating and writing the output to \fI/var/lib/motd\fP, which is usually a symbolic link to \fI/etc/motd\fP.
+
+\fBcron mode\fP
+
+By default, \fBupdate-motd\fP is executed by a series of cronjobs at specific intervals (every 10 minutes, hourly, daily, weekly, monthly).
+
+It executes lists of scripts in lexical order, concatenating and writing the output to \fI/var/lib/motd\fP, which is usually a symbolic link to \fI/etc/motd\fP.
Users and/or packages should add symbolic links to \fI/etc/update-motd.d/\fP, \fI/etc/update-motd.d/hourly\fP, \fI/etc/update-motd.d/daily\fP, \fI/etc/update-motd.d/weekly\fP, \fI/etc/update-motd.d/monthly\fP, prepended with a two-digit number to define the displayed order, as obeyed by \fBrun-parts(8)\fP.
If enabled, timestamp of the last \fBupdate-motd\fP run will be written to \fI/var/run/update-motd.lastrun\fP.
+\fBinotify mode\fP
+
+Alternatively, \fBupdate-motd\fP can execute in an inotify mode, using \fBiwatch\fP. In this case, update-motd will 'watch' the \fI/var/run/update-motd\fP directory for changes of any kind and trigger an update of \fI/etc/motd\fP.
+
+To start and stop \fBupdate-motd\fP in inotify-mode, ensure that you have the \fBiwatch\fP package installed, and run:
+ $ sudo update-motd --enable inotify
+ $ sudo update-motd --disable inotify
+
+In this mode, scripts in \fI/etc/update-motd.*/\fP will not be executed at their regular intervals by the cron job. Rather, it is the responsibility of various applications to write data to \fI/var/run/update-motd\fP, and \fBupdate-motd\fP merely picks it up and inserts into the \fI/etc/motd\fP.
+
.SH FILES
-\fI/etc/cron.d/update-motd\fP, \fI/etc/update-motd.d/\fP, \fI/etc/update-motd.d/hourly\fP, \fI/etc/update-motd.d/daily\fP, \fI/etc/update-motd.d/weekly\fP, \fI/etc/update-motd.d/monthly\fP, \fI/etc/motd.tail\fP, \fI/var/run/motd\fP, \fI/var/lib/update-motd/disabled\fP, \fI/var/run/update-motd\fP, \fI/var/run/update-motd.lastrun\fP
+\fI/etc/cron.d/update-motd\fP, \fI/etc/update-motd.d/\fP, \fI/etc/update-motd.d/hourly\fP, \fI/etc/update-motd.d/daily\fP, \fI/etc/update-motd.d/weekly\fP, \fI/etc/update-motd.d/monthly\fP, \fI/etc/motd.tail\fP, \fI/etc/update-motd/iwatch.xml\fP, \fI/var/run/motd\fP, \fI/var/lib/update-motd/disabled\fP, \fI/var/run/update-motd\fP, \fI/var/run/update-motd.lastrun\fP
.SH "AUTHOR"
.IX Header "AUTHOR"
projects / update-motd.git / commitdiff