IPerf network performance/throughput trend plot graph script

iperfplot.sh

#!/bin/bash -xeu

# ENV Vars with defaults
IPERF_HOST="${IPERF_HOST:-mercury}"
IPERF_LOG="${IPERF_LOG:-iperf.10145.log}"
SPEED_CSV="${SPEED_CSV:-speed2.csv}"
OUTPUT_PNG="${OUTPUT_PNG:-throughput2.png}"
OUTPUT_SIZE="${OUTPUT_SIZE:-1000,500}"
INTERVAL="${INTERVAL:-60}"

# Constants
TIMEFMT="%Y-%m-%d %H:%M:%S"

# Plot function, requires gnuplot to be installed
plot(){
  gnuplot <<PLOT
     set xdata time
     set timefmt "${TIMEFMT}"
     #set xrange ["2019-05-29 09:44":"2019-05-31 10:00"]
     set format x "%m/%d %H:%M"
     set datafile separator ","
     set xlabel "Date/Time"
     set ylabel "MBits/s"
     set terminal png large size ${OUTPUT_SIZE}
     set output "${OUTPUT_PNG}"
     plot "${SPEED_CSV}" using 1:2 title "IPerf to local machine across Gigabit switch"
PLOT
}

# Main loop
while :; do
  iperf -c ${IPERF_HOST} \
    |ts "${TIMEFMT}" \
    |tee -a ${IPERF_LOG}
    awk '/Mbits/{print $1,$2","$9}' ${IPERF_LOG} > ${SPEED_CSV}
    plot
  sleep ${INTERVAL}
done