set -u
MAX=2
+SYNSTATUSONLY="0"
+
+usage(){
+ ret=$1
+
+ cat <<EOF
+$0: usage:
+ $0 <options>
+
+ Check NTP sync status (per timedatectl's output) and offset to RTC clock.
+ The latter is particularly interesting for VMs.
+
+ -o <secs> Maximum offset to tolerate (Default: $MAX)
+ -s Check sync status only, do not diff against RTC.
+EOF
+
+ exit $ret
+}
+
+while getopts o:sh opt ; do
+ case "$opt" in
+ o) MAX="$OPTARG" ;;
+ s) SYNSTATUSONLY="1";;
+ h) usage 0
+ esac
+done
+shift $(($OPTIND - 1))
+if [ "$#" -gt 0 ]; then
+ usage 1 >&2
+fi
+
temp="$(mktemp)"
trap "rm -f '$temp'" EXIT
-timedatectl > "$temp"
+LC_ALL=C timedatectl > "$temp"
ut=$(sed '/Universal time:/ { s/^[^:]*: *//; p}; d' "$temp")
rtc=$(sed '/RTC time:/ { s/^[^:]*: *//; p}; d' "$temp")
+ntpenabled=$(sed '/\(NTP enabled\|Network time on\):/ { s/^[^:]*: *//; p}; d' "$temp")
+ntpsynced=$(sed '/NTP synchronized:/ { s/^[^:]*: *//; p}; d' "$temp")
-uts=$(date -d "$ut" +%s)
-rtcs=$(date -d "$rtc" +%s)
-
-d=$((uts - rtcs))
-
-if [ "$d" -lt "-$MAX" ] ||
- [ "$d" -gt "$MAX" ]; then
- echo "Warning: time desync $d: RTC vs. system time: $rtc vs. $ut"
- exit 1
+uts=$(TZ=UTC date -d "$ut" +%s)
+rtcs=$(TZ=UTC date -d "$rtc" +%s 2>/dev/null || echo "N/A")
+if [ "$rtcs" != "N/A" ]; then
+ delta=$((uts - rtcs))
fi
+if [ "$SYNSTATUSONLY" -ge 1 ]; then
+ if [ "$ntpsynced" != "yes" ]; then
+ echo "Warning: not synced with NTP."
+ exit 1
+ fi
+else
+ if [ "$rtcs" = "N/A" ]; then
+ echo "Warning: Cannot parse RTC $rtc."
+ exit 1
+ fi
-bool=$(sed '/NTP enabled:/ { s/^[^:]*: *//; p}; d' "$temp")
-if [ "$bool" != "yes" ]; then
- echo "Warning: NTP not enabled!"
- exit 1
-fi
+ if [ "$delta" -lt "-$MAX" ] ||
+ [ "$delta" -gt "$MAX" ]; then
+ echo "Warning: time desync $delta: RTC vs. system time: $rtc vs. $ut"
+ exit 1
+ fi
+
+ if [ "$ntpenabled" != "yes" ]; then
+ echo "Warning: NTP not enabled!"
+ exit 1
+ fi
-bool=$(sed '/NTP synchronized:/ { s/^[^:]*: *//; p}; d' "$temp")
-if [ "$bool" != "yes" ]; then
- echo "Warning: not synced with NTP (but clock is OK for now)."
- exit 1
+ if [ "$ntpsynced" != "yes" ]; then
+ echo "Warning: not synced with NTP (but clock is OK for now)."
+ exit 1
+ fi
fi
echo "OK: synced at $ut."