check_duplicity - Monitoring Duplicity log files

#!/bin/bash
# Checks backup statistics part of a Duplicity log file
# Provided by itefix.net
#

<<'LOG_SEGMENT_EXAMPLE'
--------------[ Backup Statistics ]--------------
StartTime 1589934609.17 (Wed May 20 02:30:09 2020)
EndTime 1589934611.97 (Wed May 20 02:30:11 2020)
ElapsedTime 2.80 (2.80 seconds)
SourceFiles 13106
SourceFileSize 1012789998 (966 MB)
NewFiles 5
NewFileSize 114206 (112 KB)
DeletedFiles 0
ChangedFiles 0
ChangedFileSize 0 (0 bytes)
ChangedDeltaSize 0 (0 bytes)
DeltaEntries 5
RawDeltaSize 77342 (75.5 KB)
TotalDestinationSizeChange 23197 (22.7 KB)
Errors 0
-------------------------------------------------
LOG_SEGMENT_EXAMPLE

# Exit codes
OK=0
WARNING=1
CRITICAL=2
UNKNOWN=3

exitcode=$UNKNOWN
codetext=("Ok" "Warning" "Critical" "Unknown")

# Usage help
usage() {

  text="
USAGE: ${0} -l <path> [-c | -w]
-l <path> : Duplicity log file path (required)
-c : return critical if errors
-w : return warning if errors
"
  echo "$text"

  exit $exitcode
}

# check for command line arguments
while getopts "l:wch" option
do
  case "$option" in
    l) logfile=$OPTARG;;
    c) exitcode=$CRITICAL;;
    w) exitcode=$WARNING;;
    h) usage;;
    *) usage;;
  esac
done

[[ -z $logfile ]] && usage

[[ ! -f $logfile ]] && echo "Log file $logfile does not exist." && exit $exitcode

# Metrics array
declare -A metrics=()

# Extract statistics from the bottom of the log file
stats=$(tail -25 $logfile | sed -n '/--------------\[ Backup Statistics \]--------------/,$p')

# Populates the metrics array, message and perfdata
# 1.argument: Metrics name, 2.argument: Nagios perfdata metrics unit (s,B,empty)
function ExtractNumericMetric ()
{
  [[ $stats =~ $1[[:blank:]]([0-9.]+)\s? ]]

  metrics[$1]=${BASH_REMATCH[1]}

  [[ -z ${metrics[$1]} ]] && echo "Metric $1 can't be extracted. Possible backup problem." && exit $UNKNOWN

  message+="$1: "

  # Human output
  case "$2" in

  s)  message+="${metrics[$1]} secs"
      ;;
  B)  sizekb=$((${metrics[$1]}/1024))
      message+="$sizekb KB"
      ;;
  *)  message+="${metrics[$1]}"
      ;;

  esac

  message+=", "

  perfdata+="$1=${metrics[$1]}$2 "

}

perfdata=""
message=""

ExtractNumericMetric StartTime
ExtractNumericMetric EndTime

start_time=$(date -d@${metrics[StartTime]})
end_time=$(date -d@${metrics[EndTime]})
message="Started: ${start_time}, Ended: ${end_time}, "
perfdata=""

# Extract metrics
ExtractNumericMetric ElapsedTime s
ExtractNumericMetric SourceFiles
ExtractNumericMetric SourceFileSize B
ExtractNumericMetric NewFiles
ExtractNumericMetric NewFileSize B
ExtractNumericMetric DeletedFiles
ExtractNumericMetric ChangedFiles
ExtractNumericMetric ChangedFileSize B
ExtractNumericMetric ChangedDeltaSize B
ExtractNumericMetric DeltaEntries
ExtractNumericMetric RawDeltaSize B
ExtractNumericMetric TotalDestinationSizeChange B
ExtractNumericMetric Errors

[[ ${metrics[Errors]} -eq 0 ]] && exitcode=$OK

echo "Duplicity ${codetext[$exitcode]} - ${message%??} | ${perfdata}"
exit $exitcode