wget based cache warmer script

warmly.sh

#!/bin/bash

# RUN
# CACHE_WARMER_LOGFILE=~/cache_warmer.log bash <(curl -# -L http://bit.ly/signalwerk-warmly) https://xyz.com

# wget based cache warmer script
# Original Author: Thomas Fritz
# https://gist.github.com/thomasfr/7926314

CURRENT_DIR="$(pwd)"
SCRIPT_DIR="$(cd "$(dirname "$0")"; pwd)"
cd "$CURRENT_DIR"

DEFAULT_USER_AGENT="Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; CACHE_WARMER)"
USER_AGENT="${2:-$DEFAULT_USER_AGENT}"
START_URL="${1}"
WAIT_NEXT_RUN="600s"
WGET_LOGFILE="${CACHE_WARMER_LOGFILE:-$SCRIPT_DIR/wget.log}"
WAIT_BETWEEN_REQUESTS="0.5"
REJECT_EXTENSIONS="gif,jpg,jpeg,png,pdf,txt,xml,ico,svg,css,js,json"
RUN_COUNT=1

if [ -z "$START_URL" ]; then
    echo "No starting URL set"
    exit 1
fi

echo "Using User-Agent: '$USER_AGENT'"
echo "Cache warming starts at: '$START_URL'"

echo "$(date) START"
while :; do
    echo "$(date) START RUN #${RUN_COUNT}"
    wget --no-cache \
         --reject="${REJECT_EXTENSIONS}" \
         --wait="${WAIT_BETWEEN_REQUESTS}" \
         --limit-rate=400k \
         --delete-after \
         --recursive \
         --no-directories \
         --timestamping \
         --level=3 \
         --tries=3 \
         --timeout=20 \
         --no-verbose \
         --output-file="${WGET_LOGFILE}" \
         --user-agent="${USER_AGENT}" \
         "${START_URL}"
    if [ $? -gt 0 ]; then
        exit 1
    fi
    echo "$(date) WAIT '${WAIT_NEXT_RUN}' for next run"
    sleep "${WAIT_NEXT_RUN}"
    let "RUN_COUNT=RUN_COUNT+1"
done