monitor_docker_memory_stat.sh

#!/bin/bash

set -e

# Interval in seconds.
INTERVAL="1"
TIMEFORMAT="%d-%m-%y,%H:%M:%S"

echo "Monitor the memory usage of a running docker container (memory in MBs)"

example="./monitor_docker_memory_stat.sh ccec200a349403170ba088650a6a664f35ef895b6bc734de89eacb887a1ffde6 rss"
if [ -z $1 ];
then
    echo "Error: No container id provided. E.g. $example"
    exit 1
fi

if [ -z $2 ];
then
    echo "Error: No memory variable name provided. E.g. $example"
    exit 1
fi

containerid=$1
statname=$2

dir="$( cd "$( dirname "${BASH_SOURCE[0]}" )" >/dev/null 2>&1 && pwd )"

if [ ! -d "$dir/data" ];
then
    mkdir "$dir/data"
fi

filename=$statname.data
file="$dir/data/$filename"
plotfile=$dir'/'$statname'plot.gn'

cat > "$plotfile" <<EOL
set title "$statname value"
set xdata time
set timefmt "$TIMEFORMAT"
set xtics format "$TIMEFORMAT"
plot [:][:] 'data/$filename' using 1:2 with line
while (1) {
    replot
    pause 1
}
EOL

if [ -f $file ];
then
    rm "$file"
fi
touch "$file"

i=0
while true; do
    sudo cat /sys/fs/cgroup/memory/docker/$containerid/memory.stat | grep "^$statname " | { date +$TIMEFORMAT & grep "[0-9]*$" --only-matching | awk '{print $1/1024/1024}'; } | xargs echo >> $file

    if [ $i -eq 10 ]; then
        echo 'gets in'
        gnuplot $plotfile &
    fi
    i=$((i+1))
    sleep $INTERVAL
done

exit 0