#!/usr/bin/env bash
# shellcheck disable=SC2086
#
# archive catalina.out
#
# SPDX-License-Identifier: MIT

## SETTINGS MUST BE CHANGED TO USE THIS SCRIPT ##

# This script will operate on the already rotated catalina.out logfiles
# generated by the changing catalina.sh to use a piped logging method
# such as:
#
#  org.apache.catalina.startup.Bootstrap "$@" start \
#  |/usr/bin/rotatelogs "$CATALINA_BASE"/logs/catalina.out.%Y%m%d-%H%M 200M >> /dev/null 2>&1 &

# Run this from crontab nightly at an off hour,
# as gzip can suck up some serious CPU on huge logs:
# 0 2 * * * /opt/sbin/archivecatalina.sh

########## SETTINGS BEGIN ##########

# ARCHIVE_METHOD settings
# 0 = unset (default)
# 1 = compress in place
# 2 = move to another location
# 3 = compress and move
ARCHIVE_METHOD=0

# DURATION_KEEP setting
# <n> = number of days prior to keep around
DURATION_KEEP=28

# CATALINA_LOGS setting
# path to source catalina.out.* files
CATALINA_LOGS=/usr/local/tomcat/logs

# CATALINA_ARCH setting
# path to store older logs based on ARCHIVE_METHOD=2 or 3
# NOTE: this directory is NOT autocleaned on purpose!!
CATALINA_ARCH=/mnt/server/arclogs

# DURATION_WORK setting
# <n> = number of days prior to start working (default 1 day)
DURATION_WORK=1

########## SETTINGS END ##########

# What's our log name
LOG_BASE="catalina.out"

# Errorlevels
ERR_ERROR=33
ERR_PANIC=66

# Default RedHat program locations
MV=/bin/mv
DT=/bin/date
RM=/bin/rm
ID=/usr/bin/id
GZ=/usr/bin/gzip

# Are we root?
USER=$($ID -u)
if [ "X$USER" != "X0" ]; then
  echo "PANIC: Only root can run this script!"
  exit $ERR_PANIC
fi

# Sanity checks
if [ $ARCHIVE_METHOD -eq 0 ]; then
  echo "PANIC: ARCHIVE_METHOD is set to 0, please configure the script."
  exit $ERR_PANIC
fi
if [ $DURATION_WORK -lt 1 ]; then
  echo "PANIC: DURATION_WORK is set to less than one day."
  exit $ERR_PANIC
fi
if [ $DURATION_KEEP -le $DURATION_WORK ]; then
  echo "PANIC: DURATION_KEEP is less than or equal to DURATION_WORK."
  exit $ERR_PANIC
fi

# Does the source path exist?
if [ ! -x "$CATALINA_LOGS" ]; then
  echo "ERROR: $CATALINA_LOGS doesn't exist!"
  exit $ERR_ERROR
fi

# Backup dir exists/writable?
if [ $ARCHIVE_METHOD -eq 2 ] || [ $ARCHIVE_METHOD -eq 3 ]; then
  if [ ! -x "$CATALINA_ARCH" ]; then
    echo "ERROR: $CATALINA_ARCH doesn't exist or isn't writable!"
    exit $ERR_ERROR
  fi
fi

# generate fromat stamps
DATE_WORK=$($DT --date "now - $DURATION_WORK days" +"%Y%m%d")
DATE_KEEP=$($DT --date "now - $DURATION_KEEP days" +"%Y%m%d")

# log actions below depends on formatting looking like:
# /some/path/catalina.out.20100520-1345 (YYYYMMDD-HHMM)
# (.gz is accounted for)

# ARCHIVE_METHOD=1
compress_keep (){
  for logfile in "$CATALINA_LOGS/$LOG_BASE."*; do
    # if it ends in gz it's already compressed
    if [ "${logfile:(-3):3}" == ".gz" ]; then
      continue
    else
      # grab the %Y%m%d out of the name
      DTS=${logfile:(-13):8}
      if [ $DTS -ge $DATE_KEEP ] && [ $DTS -le $DATE_WORK ]; then
        # compress in place
        $GZ "$logfile"
      fi
    fi
  done
}

# ARCHIVE_METHOD=2
move_only (){
  for logfile in "$CATALINA_LOGS/$LOG_BASE."*; do
    # strip off .gz, we don't care if it's compressed
    logtemp=${logfile%.gz}
    DTS=${logtemp:(-13):8}
    if [ $DTS -ge $DATE_KEEP ] && [ $DTS -le $DATE_WORK ]; then
      $MV -f "$logfile" "$CATALINA_ARCH/"
    fi
  done
}

# ARCHIVE_METHOD=3
compress_move (){
  for logfile in "$CATALINA_LOGS/$LOG_BASE."*; do
    logtemp=${logfile%.gz}
    DTS=${logtemp:(-13):8}
    if [ $DTS -ge $DATE_KEEP ] && [ $DTS -le $DATE_WORK ]; then
      # already compressed
      if [ ${logfile:(-3):3} == ".gz" ]; then
        $MV -f "$logfile" "$CATALINA_ARCH/"
      else
        $GZ -c "$logfile" >> "$CATALINA_ARCH/$logfile.gz"
        $RM -f "$logfile"
      fi
    fi
  done
}

# cleanup older than DURATION_KEEP
cleanup_older (){
  for logfile in "$CATALINA_LOGS/$LOG_BASE."*; do
    logtemp=${logfile%.gz}
    DTS=${logtemp:(-13):8}
    if [ $DTS -lt $DATE_KEEP ]; then
      $RM -f "$logfile"
    fi
  done
}

# the main case
case $ARCHIVE_METHOD in
  1)
    compress_keep
    ;;
  2)
    move_only
    ;;
  3)
    compress_move
    ;;
  *)
    echo "PANIC: Invalid ARCHIVE_METHOD settting: $ARCHIVE_METHOD"
    exit $ERR_PANIC
esac

# do a final cleanup
cleanup_older

exit 0