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 case "$1" in
  23   -h|--help)
  24     cat <<EOF
  25 Usage: sysd-log-once [-ERRORS] SERVICE COMMAND [ARGS...]
  26 For systemd timers, email on repeated failure & success after failure.
  27
  28 In the service triggered by the timer, prepend this script to the ExecStart.
  29 The email will contain the service's logs for the last ERRORS runs.
  30
  31
  32 Stores error counts in $cbase
  33
  34 -ERRORS:  ERRORS is the number of failurs to accumulate before mailing the error.
  35           Default is 3.
  36 EOF
  37     exit 0
  38     ;;
  39   -[0-9]*)
  40     errors=${1#-}
  41     shift
  42     ;;
  43 esac
  44 service=$1
  45 shift
  46
  47 c=$cbase/$service # c for command file path base
  48
  49 glob="$c[0-9]*"
  50 arr=($glob); file="${arr[0]}"; [[ $glob != "$file" ]] || file=
  51 u=${USER:-root}
  52 [[ -d $cbase ]] || mkdir -p $cbase
  53
  54 if [[ ! $file ]]; then
  55   cursor=$(journalctl --show-cursor -qn0|sed 's/^\s*--\scursor:\s*//')
  56 fi
  57
  58 code=0
  59 "$@" || code=$?
  60 if (( code )); then
  61   send_mail=false
  62   if [[ $file ]]; then
  63     i=${file#$c}
  64     if (( i < errors )); then
  65       new_file=$c$((i+1))
  66       mv $file $new_file
  67       file=$new_file
  68       if [[ $file == $c$errors ]]; then
  69         send_mail=true
  70       fi
  71     fi
  72   else
  73     file=${c}1
  74     printf "%s\n" "$cursor" >$file
  75     if (( errors == 1 )); then
  76       send_mail=true
  77     fi
  78   fi
  79   if $send_mail; then
  80     journalctl -u $service.service --after-cursor=$(<$file) | \
  81       mail -s "$HOSTNAME: $service exit code: $code" $u@localhost
  82   fi
  83 else
  84   if [[ $file ]]; then
  85     rm -f $file
  86     if [[ $file == $c$errors ]]; then
  87       echo | mail -s "$HOSTNAME: $service success" $u@localhost
  88     fi
  89   fi
  90 fi