Monitor your ADSL Connection for Outages & Uptime

I had the misfortune of choosing demon as my ISP and for the first couple of months managed to exceed my fair use policy and experience extended outages. In an effort to document my issues I wrote a couple of scripts on a NetBSD box that monitor the connection and automatically create a graph using gnuplot of the uptime.

The scripts are driven by a crontab script:

        $ crontab -l
        SHELL=/bin/sh
        MAILTO=msw
        @hourly /home/msw/router/getstats
        5,10,15,20,25,30,35,40,45,50,55 * * * * /home/msw/router/ping-internet.sh
        5,10,15,20,25,30,35,40,45,50,55 * * * * /home/msw/router/plot-stats.sh
        0,15,30,45 * * * *      /home/msw/router/upload-stats.sh

Every five minutes the ping-internet.sh script attempts to ping one of the demon nameservers using its' IP address:

        #!/usr/pkg/bin/bash
        LOGFILE=/home/msw/router/ping-stats.txt
        TIME="`date +%C%y%m%d%H%M`"
        /sbin/ping -c 1 158.152.1.58 > /dev/null 2>&1
        if [ "$?" == "0" ]
        then
                STATUS=1
        else
                STATUS=0
        fi
        echo "$TIME $STATUS" >> $LOGFILE

This generates a line in the LOGFILE which looks like this:

        200907091945 1
        200907091950 1
        200907091955 1
        200907092005 1
        200907092010 1
        200907092015 1
        200907092020 1
        200907092025 1
        200907092030 1
        200907092035 1

where the first number is the date and time and the second number is a '1' if the ping was successful, or a '0' if it was not.

The plot-stats.sh script turns these numbers into a nice graph with the help of GnuPlot then puts the resulting jpeg onto the local apache webserver:

        #!/usr/pkg/bin/bash
        sleep 30
        export PATH=/bin:/sbin:/usr/pkg/bin
        export RS=/home/msw/router
        export HTDOCS=/usr/pkg/share/httpd/htdocs
        export STATS_FILE=$RS/ping-stats.txt
        export JPG_FILE=ping-stats.jpg
        export SHARE_DIR=/usr/local/archive
        export HTTPD_DIR=/usr/pkg/share/httpd/htdocs
        cp $STATS_FILE $RS/ping-stats-copy.txt
        gnuplot $RS/plot-stats.gnuplot > $SHARE_DIR/$JPG_FILE
        cp $SHARE_DIR/$JPG_FILE $HTTPD_DIR

The gnuplot script plot-stats.gnuplot that works the magic:

        set terminal jpeg large size 1024, 600
        #set terminal dumb
        set title "Demon Internet HomeOffice 8000, hostname: waldo"
        set lmargin 10
        set rmargin 10
        set tmargin 5
        set bmargin 8
        set xdata time
        set format x "%d/%m"
        set xlabel "Date, 2009" offset 0,-2
        set ylabel "ADSL Status"
        set yrange [-1:2]
        set ytics 0,1,1 ("Off" 0, "On" 1)
        set mxtics 6
        set timefmt "%Y%m%d%H%M%S"
        plot "/home/msw/router/ping-stats-copy.txt" using 1:2 with lines title
        "Status at `date`"
        #set title "ADSL status" offset 0,-10
        # - generated on %Y%m%d %H%M"
        show title

Then once every 1/4 hour the upload-stats.sh script pushes the stats up to my remote web host (assuming the connection is up of course!)

        #!/usr/pkg/bin/bash
        cp /usr/local/archive/ping-stats.jpg /tmp
        cd /tmp
        ftp ftp://username:password@ftp.wickensonline.co.uk <<-END_OF_INPUT
                bin
                cd public_html
                put ping-stats.jpg
                dir
                bye
        END_OF_INPUT

The end result being this lovely image: