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 [COMMAND_ARGS...]
  27
  28 For use with systemd timers, to email (with exim) on repeated failure &
  29 success after failure.
  30
  31 In the service triggered by the timer, prepend this script to the ExecStart.
  32 The email will contain the service's logs for the last ERRORS runs.
  33
  34
  35 Stores error counts in $cbase
  36
  37 -ERRORS:  ERRORS is the number of failurs to accumulate before mailing the error.
  38           Default is 3.
  39
  40 -t TO_ADDRESS:  Address to email about errors
  41 EOF
  42     exit 0
  43     ;;
  44   -[0-9]*)
  45     errors=${1#-}
  46     shift
  47     ;;
  48   -t)
  49     to="$2"
  50     shift 2
  51     ;;
  52 esac
  53 service=$1
  54 shift
  55
  56 c=$cbase/$service # c for command file path base
  57
  58 glob="${c}[0-9]*"
  59 arr=($glob); file="${arr[0]}"; [[ $glob != "$file" ]] || file=
  60 [[ -d $cbase ]] || mkdir -p $cbase
  61
  62 if [[ ! $file ]]; then
  63   cursor=$(journalctl --show-cursor -qn0|sed 's/^\s*--\scursor:\s*//')
  64 fi
  65
  66 code=0
  67 "$@" || code=$?
  68 if (( code )); then
  69   send_mail=false
  70   if [[ $file ]]; then
  71     i=${file#"$c"}
  72     if (( i < errors )); then
  73       new_file=$c$((i+1))
  74       mv $file $new_file
  75       file=$new_file
  76       if [[ $file == $c$errors ]]; then
  77         send_mail=true
  78       fi
  79     fi
  80   else
  81     file=${c}1
  82     printf "%s\n" "$cursor" >$file
  83     if (( errors == 1 )); then
  84       send_mail=true
  85     fi
  86   fi
  87   if $send_mail; then
  88       exim -odf -t <<EOF
  89 To: $to
  90 From: $USER@$(hostname -f)
  91 Subject: $HOSTNAME: $service exit code: $code
  92
  93 $(journalctl -u $service.service --after-cursor="$(<$file)")
  94 EOF
  95   fi
  96 else
  97   if [[ $file ]]; then
  98     rm -f $file
  99     if [[ $file == $c$errors ]]; then
 100       exim -odf -t <<EOF
 101 To: $to
 102 From: $USER@$(hostname -f)
 103 Subject: $HOSTNAME: $service success
 104
 105 EOF
 106     fi
 107   fi
 108 fi