trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
errors=3
-cbase=$HOME/sysd-mail-once-state
-case "$1" in
+tmp=(~)
+cbase="${tmp[0]}/sysd-mail-once-state"
+to=root
+dryrun=false
+while [[ $1 == -* ]]; do
+ case "$1" in
-h|--help)
- cat <<EOF
-Usage: sysd-log-once [-ERRORS] SERVICE COMMAND [ARGS...]
-For systemd timers, email on repeated failure & success after failure.
+ cat <<EOF
+Usage: sysd-mail-once [-t TO_ADDRESS] [-ERRORS] SERVICE COMMAND [COMMAND_ARGS...]
+
+For use with systemd timers, to email (with exim) on repeated failure &
+success after failure.
In the service triggered by the timer, prepend this script to the ExecStart.
The email will contain the service's logs for the last ERRORS runs.
Stores error counts in $cbase
--ERRORS: ERRORS is the number of failurs to accumulate before mailing the error.
- Default is 3.
+-ERRORS ERRORS is the number of failurs to accumulate before mailing the error.
+ Default is 3.
+
+-t TO_ADDRESS Address to email about errors
+-n Dry run. Execute command but only print out what we would do in response.
EOF
- exit 0
- ;;
+ exit 0
+ ;;
-[0-9]*)
- errors=${1#-}
- shift
- ;;
-esac
-service=$1
+ errors=${1#-}
+ ;;
+ -t)
+ to="$2"
+ shift
+ ;;
+ -n)
+ dryrun=true
+ ;;
+ *)
+ echo "error: unexpected arg: $1"
+ exit 1
+ ;;
+ esac
+ shift
+done
+
+if (( $# < 2 )); then
+ echo "error: expected at least 2 args after options. args:"
+ exit 1
+fi
+
+service="$1"
shift
-c=$cbase/$service
-glob="$c[0-9]*"
+# maybe run, depending on $dryrun
+m() {
+ if $dryrun; then
+ printf "%s\n" "$*"
+ else
+ "$@"
+ fi
+}
+# maybe run, with stdin
+mi() {
+ if $dryrun; then
+ printf "%s <<'EOF'\n" "$*"
+ cat
+ echo EOF
+ else
+ "$@"
+ fi
+}
+e() {
+ printf "dryrun: %s\n" "$*"
+}
+
+c=$cbase/$service # c for command file path base
+
+if $dryrun; then
+ e "c=$c"
+fi
+
+glob="${c}[0-9]*"
arr=($glob); file="${arr[0]}"; [[ $glob != "$file" ]] || file=
-u=${USER:-root}
-[[ -d $cbase ]] || mkdir -p $cbase
+if [[ $dryrun && $file ]]; then
+ e "file=$file"
+fi
+
+if ! [[ -d $cbase ]]; then
+ mkdir -p $cbase
+fi
if [[ ! $file ]]; then
- cursor=$(journalctl --show-cursor -qn0|sed 's/^\s*--\scursor:\s*//')
+ cursor=$(journalctl --show-cursor -qn0|sed 's/^\s*--\scursor:\s*//')
fi
-if "$@"; then
- if [[ $file ]]; then
- rm -f $file
- if [[ $file == $c$errors ]]; then
- echo | mail -s "$HOSTNAME: $service success" $u@localhost
- fi
+
+code=0
+"$@" || code=$?
+if (( code )); then
+ send_mail=false
+ if [[ $file ]]; then
+ i=${file#"$c"}
+ if (( i < errors )); then
+ new_file=$c$((i+1))
+ m mv $file $new_file
+ file=$new_file
+ if [[ $file == $c$errors ]]; then
+ send_mail=true
+ fi
fi
-else # $@ failed
- if [[ $file ]]; then
- i=${file#$c}
- if (( i < errors )); then
- new_file=$c$((i+1))
- mv $file $new_file
- file=$new_file
- if [[ $file == $c$errors ]]; then
- journalctl -u $service.service --after-cursor=$(<$file) | \
- mail -s "$HOSTNAME: $service failure" $u@localhost
- fi
- fi
+ else
+ file=${c}1
+ if $dryrun; then
+ printf "dryrun: creating $file, contents: %s\n" "$cursor"
else
- file=${c}1
- printf "%s\n" "$cursor" >$file
+ printf "%s\n" "$cursor" >$file
+ fi
+ if (( errors == 1 )); then
+ send_mail=true
+ fi
+ fi
+ if $send_mail; then
+ echo "sysd-mail-once: emailing on $errors errors. exit code: $code"
+ mi exim -odf -t <<EOF
+To: $to
+From: $(id -u -n)@$(hostname -f)
+Subject: $HOSTNAME: $service exit code: $code
+
+$(journalctl -u $service.service --after-cursor="$(<$file)")
+EOF
+ fi
+else
+ if [[ $file ]]; then
+ m rm -f $file
+ if [[ $file == $c$errors ]]; then
+ echo "sysd-mail-once: emailing success after >= $errors errors."
+ mi exim -odf -t <<EOF
+To: $to
+From: $(id -u -n)@$(hostname -f)
+Subject: $HOSTNAME: $service success
+
+EOF
fi
+ fi
fi