Some basic network monitoring scripts

track_stuff.sh

#!/bin/bash

# Perform some basic DNS, TCP, TLS, and ICMP testing targeting a remote endpoint or two,
# to spot transient issues you'd normally miss in 5-minute aggregate date
#
# DNS-TCP pings are emitted as a CSV to stdout, floodping is emitted to stderr

# Example of how to run it and capture both outputs.
#  NOTE: In the stderr redirect target shell, the stdout gets captured by the stdout subshell,
#        so we need to foce that to stderr.
# sudo bash monitor.sh "dontfloodmewithicmp.com" "floodmewithicmp.com" \
#    > >(tee -a `date +%F`.tcping.csv) 2> >(tee -a `date +%F`.pingf.csv >&2)

# Examples of how to run it and capture both outputs.
# sudo bash monitor.sh "dontfloodmewithicmp.com" > >(tee -a `date +%F`.tcping.csv) 2> >(tee -a `date +%F`.pingf.csv)

dnstcp_target="$1"
if [ "$1" != "" ]
then
    (echo "unixtime,host,rtt"
    while [ true ]
    do
        echo "`date -u +%s.%N`,${dnstcp_target},`(
            time nc -vzw2 "${dnstcp_target}" 443) 2>&1 |
            grep  --line-buffered real | tr 's' 'm' |
            cut -d 'm' -f2`"
        sleep 0.5
    done) &
    dnstcp_pid="$!"
fi

flood_ping_target="$2"

if [ "$2" != "" ]
then
    (
        echo "unixtime,num_transmitted,num_received,percent_loss,rtt_min,rtt_avg,rtt_max,rtt_mdev,ipg,ewma" >&2
        while [ true ]
        do
            date -u +"%s.%N"; sudo ping -f "${flood_ping_target}" -w 10
        done |
        sed --unbuffered -n '/^[0-9]*\.[0-9]*/{:a;{/\nrtt/!{N;ba}};s/\n/ /gp}' | tr '/' ' ' |
        sed --unbuffered -n 's/^\([^ ]*\) .* \([0-9]*\) packets trans.* \([0-9]*\) recei.* \([0-9.]*\). packet loss.* = \([^ ]*\) \([^ ]*\) \([^ ]*\) \([^ ]*\) ms.* ewma \([^ ]* [^ ]*\) .*$/\1,\2,\3,\4,\5,\6,\7,\8,\9/p' |
        while read line
        do
            # `tr` has no ability to line-buffer, which is insane.
            echo "$line" | tr ' ' ',' >&2
        done >&2
    ) >&2 &
    flood_ping_pid="$!"
fi

finish() {
    pkill -9 -P $dnstcp_pid
    pkill -9 -P $flood_ping_pid
    kill -9 $dnstcp_pid
    kill -9 $flood_ping_pid
    exit 0
}

trap 'finish' SIGINT

if [ "$dnstcp_pid" != "" ]
then
    wait "$dnstcp_pid"
fi

if [ "$flood_ping_pid" != "" ]
then
    wait "$flood_ping_pid"
fi