Merge ~kotodama/ubuntu-mirror-charm:kotodama into ubuntu-mirror-charm:master

[Loïc Gomez]

Fixing CRIT alerting over the weekend:

- do not CRIT on weekends for mirrors that can stay out of date for 4 days+
- preemptively CRIT on Friday instead of WARN, if it would CRIT over the weekend

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Laurent Sesquès (sajoupa)]

review: Approve

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

Change successfully merged at revision 27896e15879f6170112ff6558ad2d83085f38747

diff --git a/files/check-updates.sh b/files/check-updates.sh
index 3fb11bc..144171d 100755
--- a/files/check-updates.sh
+++ b/files/check-updates.sh
@@ -26,6 +26,8 @@ if [ ! -r ${LOGFILE} ]; then
 fi
 
 now=$(date +"%s")
+# Day of week, 1 = mon
+dow=$(date +"%u")
 file_mtime=$(stat --format="%Y" ${LOGFILE})
 
 file_age=$(($now - $file_mtime))
@@ -34,6 +36,9 @@ function days {
     echo $(( $1 * 24 * 3600 ))
 }
 
+# If mirror crit_age > weekend_threshold, do not crit on weekends
+weekend_threshold=$(days 4)
+
 case $NAME in
     extras.ubuntu.com)
 	# This will never be updated again.
@@ -53,9 +58,23 @@ esac
 warn_age=$(( crit_age / 2 ))
 
 if [ ${file_age} -gt $crit_age ]; then
+    # If we're on weekend and crit threshold is longer than weekend threshold, that's not critical
+    # dow = 6 = Saturday
+    if [ ${dow} -ge 6 -a ${crit_age} -ge ${weekend_threshold} ]; then
+        echo "WARNING Mirror ${NAME} [Has not updated for at least $(( $crit_age / 3600 )) hours] - Weekend shield WARN-only !"
+        exit 1
+    fi
     echo "CRITICAL Mirror ${NAME} [Has not updated for at least $(( $crit_age / 3600 )) hours]"
     exit 2
 elif [ ${file_age} -gt $warn_age ]; then
+    # If we're a Friday, and that alert would CRIT over the weekend, CRIT now !
+    monday_ts=$(date +"%s" -d "next monday")
+    monday_file_age=$(($monday_ts - $file_mtime))
+    # dow = 5 = Friday
+    if [ ${dow} -eq 5 -a ${monday_file_age} -gt ${crit_age} ]; then
+        echo "CRITICAL Mirror ${NAME} [Has not updated for at least $(( $warn_age / 3600 )) hours] - Weekend shield pre-CRIT !"
+        exit 2
+    fi
     echo "WARNING Mirror ${NAME} [Has not updated for at least $(( $warn_age / 3600 )) hours]"
     exit 1
 fi