logentries-dailydownload

#!/bin/bash

# ****************************************************************************
#           .:: LogEntries Downloader - Daily Downloader ::.
#
#   Author: Sylvain Mauduit (@Swop)
#   Company: Simple IT - http://www.simple-it.fr
#
#   Usage:
#   $ logentries-dailydownload [-d logs_dir] [-z] [-s] [-m] [-p prefix]
#
# ****************************************************************************

# Check if dependencies are installed
DEPENDANCIES="readlink"
for DEPT in $DEPENDANCIES; do
  command -v $DEPT >/dev/null 2>&1 || { echo "'$DEPT' is required but it's not installed. Aborting." >&2; exit 1; }
done

SCRIPT_PATH=$(dirname `readlink -m "$0"`)

# Print program usage
function usage()
{
cat << EOF

usage: $0 options

Download the previous daylogs from Logentries, and organize logs into clean 
date-style folder architecture.

OPTIONS:
   -h               Show this message
   -d logs_dir      Directory to use for log storage 
                    (default: /var/log/logentries)
   -m               Create root logs_dir if absent
   -p prefix        Prefix to use in logfile name (default: app)
   -z               Compress logfiles
   -s               Create a symlink to previous day logs, in logs folder root.
EOF
}

function log()
{
    echo "`date --iso-860=seconds` $1"
}

function logerr()
{
    echo "`date --iso-860=seconds` $1" >&2
}

log "Start download of logs"

# Parse arguments
LOGS_DIRECTORY=/var/log/logentries
PREFIX=app
MKDIR=false
COMPRESS_LOGS=false
CREATE_SYMLINK=false
while getopts “hd:zmp:s” OPTION
do
    case $OPTION in
        h)
            usage
            exit 0
            ;;
        d)
            LOGS_DIRECTORY=$(readlink -m "$OPTARG")
            ;;
        z)
            command -v gzip >/dev/null 2>&1 || { echo "'gzip' is required but it's not installed. Aborting." >&2; exit 1; }
            COMPRESS_LOGS=true
            ;;
        m)
            MKDIR=true
            ;;
        p)
            PREFIX=$OPTARG
            ;;
        s)
            CREATE_SYMLINK=true
            ;;
        ?)
            usage
            exit 1
            ;;
    esac
done

# Check the validity of logs directory path
if [[ -d $LOGS_DIRECTORY ]]; then
    if [[ ! -w $LOGS_DIRECTORY ]]; then
        logerr "Logs directory must have write permission. Aborting."
        exit 1
    fi
else
    if $MKDIR; then
            mkdir $LOGS_DIRECTORY
            if [ $? -ne 0 ]; then
                logerr "Error during creation of root log directory. Aborting."
                exit 1
            fi
    else
        logerr "Logs directory doesn't exists. Aborting."
        exit 1
    fi
fi

# Symlink can't be created if logs are compressed
if $CREATE_SYMLINK && $COMPRESS_LOGS; then
    logerr "Symlink creation can't be coupled with log compression. Aborting."
    exit 1
fi

YESTERDAY_YEAR=$(date --utc -d "`date +%D` -1day" +%Y)
YESTERDAY_MONTH=$(date --utc -d "`date +%D` -1day" +%m)
YESTERDAY_DAY=$(date --utc -d "`date +%D` -1day" +%d)

LOGFILE_NAME="${PREFIX}_${YESTERDAY_DAY}.log"
LOGFILE_PARENT_PATH=${LOGS_DIRECTORY}/${YESTERDAY_YEAR}/${YESTERDAY_MONTH}
LOGFILE_PATH=${LOGFILE_PARENT_PATH}/${LOGFILE_NAME}

# Create folder architecture
mkdir -p $LOGFILE_PARENT_PATH
if [ $? -ne 0 ]; then
    logerr "Error during creation of directory architecture. Aborting."
    exit 1
fi

# Check if target log file can be write
if [ -f $LOGFILE_PATH ] && [ ! -w $LOGFILE_PATH ]; then
    logerr "The log file '$LOGFILE_NAME' already exists and is not writable. Aborting."
    exit 1
fi

# Get the logs
${SCRIPT_PATH}/logentries-downloader -y -q > $LOGFILE_PATH
if [ $? -ne 0 ]; then
    logerr "Error during log fetching. Aborting."
    exit 1
fi

# Compress logs
if $COMPRESS_LOGS; then
    gzip -f $LOGFILE_PATH
    if [ $? -ne 0 ]; then
        logerr "Error during log compression. Aborting."
        exit 1
    fi
fi

# Create symlink
if $CREATE_SYMLINK; then
    if [[ ! -L ${LOGS_DIRECTORY}/${PREFIX}_yesterday.log ||  \
        ! -w ${LOGS_DIRECTORY}/${PREFIX}_yesterday.log || \
        ! -w ${LOGS_DIRECTORY} ]]; then 
        logerr "Symlink could not be created (a previous file with the \
same name already exists and could not be overwritten). Aborting."
        exit 1
    fi
    rm -rf ${LOGS_DIRECTORY}/${PREFIX}_yesterday.log
    ln -s $LOGFILE_PATH ${LOGS_DIRECTORY}/${PREFIX}_yesterday.log
    if [ $? -ne 0 ]; then
        logerr "Error during symlink creation. Aborting."
        exit 1
    fi
fi