iankelling.org Git - log-quiet/blob - sysd-mail-once

   1 #!/bin/bash
   2 # Copyright (C) 2016 Ian Kelling
   3
   4 # Licensed under the Apache License, Version 2.0 (the "License");
   5 # you may not use this file except in compliance with the License.
   6 # You may obtain a copy of the License at
   7
   8 #     http://www.apache.org/licenses/LICENSE-2.0
   9
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS,
  12 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13 # See the License for the specific language governing permissions and
  14 # limitations under the License.
  15
  16
  17 set -eE -o pipefail
  18 trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
  19
  20 errors=3
  21 cbase=$HOME/sysd-mail-once-state
  22 to=root
  23 case "$1" in
  24   -h|--help)
  25     cat <<EOF
  26 Usage: sysd-mail-once [-t TO_ADDRESS] [-ERRORS] SERVICE COMMAND [ARGS...]
  27 For systemd timers, email on repeated failure & success after failure.
  28
  29 In the service triggered by the timer, prepend this script to the ExecStart.
  30 The email will contain the service's logs for the last ERRORS runs.
  31
  32
  33 Stores error counts in $cbase
  34
  35 -ERRORS:  ERRORS is the number of failurs to accumulate before mailing the error.
  36           Default is 3.
  37 EOF
  38     exit 0
  39     ;;
  40   -[0-9]*)
  41     errors=${1#-}
  42     shift
  43     ;;
  44   -t)
  45     to="$2"
  46     shift 2
  47     ;;
  48 esac
  49 service=$1
  50 shift
  51
  52 c=$cbase/$service # c for command file path base
  53
  54 glob="$c[0-9]*"
  55 arr=($glob); file="${arr[0]}"; [[ $glob != "$file" ]] || file=
  56 [[ -d $cbase ]] || mkdir -p $cbase
  57
  58 if [[ ! $file ]]; then
  59   cursor=$(journalctl --show-cursor -qn0|sed 's/^\s*--\scursor:\s*//')
  60 fi
  61
  62 code=0
  63 "$@" || code=$?
  64 if (( code )); then
  65   send_mail=false
  66   if [[ $file ]]; then
  67     i=${file#$c}
  68     if (( i < errors )); then
  69       new_file=$c$((i+1))
  70       mv $file $new_file
  71       file=$new_file
  72       if [[ $file == $c$errors ]]; then
  73         send_mail=true
  74       fi
  75     fi
  76   else
  77     file=${c}1
  78     printf "%s\n" "$cursor" >$file
  79     if (( errors == 1 )); then
  80       send_mail=true
  81     fi
  82   fi
  83   if $send_mail; then
  84     journalctl -u $service.service --after-cursor=$(<$file) | \
  85       mail -s "$HOSTNAME: $service exit code: $code" "$to"
  86   fi
  87 else
  88   if [[ $file ]]; then
  89     rm -f $file
  90     if [[ $file == $c$errors ]]; then
  91       echo | mail -s "$HOSTNAME: $service success" "$to"
  92     fi
  93   fi
  94 fi