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/$service
  48
  49 glob="$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 if "$@"; then
  58   if [[ $file ]]; then
  59     rm -f $file
  60     if [[ $file == $c$errors ]]; then
  61       echo | mail -s "$HOSTNAME: $service success" $u@localhost
  62     fi
  63   fi
  64 else # $@ failed
  65   if [[ $file ]]; then
  66     i=${file#$c}
  67     if (( i < errors )); then
  68       new_file=$c$((i+1))
  69       mv $file $new_file
  70       file=$new_file
  71       if [[ $file == $c$errors ]]; then
  72         journalctl -u $service.service --after-cursor=$(<$file) | \
  73           mail -s "$HOSTNAME: $service failure" $u@localhost
  74       fi
  75     fi
  76   else
  77     file=${c}1
  78     printf "%s\n" "$cursor" >$file
  79   fi
  80 fi