cccheck

#!/bin/bash
## cccheck
##
## Check for connections of a specific container across EC2 (ECS/docker) instances
## Will not fail if no containers are found
##
#

if [ $# -eq 0 -o $# -gt 2 ]; then
	echo "Usage: cccheck container-name1[,container-name-2,container-name3...container-name-N] [TIME_WAIT]" 1>&2
	exit 1
fi

CONTAINERS="$1" ## container names
ST="$2" ## optional

## program starts here

PAD=45

## get own IP
IPv4=$(/sbin/ifconfig eth0 | grep 'inet addr:' | cut -d: -f2 | awk '{ print $1}')
if [ -z "$IPv4" ]; then
	echo "ERROR: could not get IPv4 of eth0" 1>&2
	exit 1
fi

TMPF=$(mktemp)

## access ip_conntrack via sudo only once
if [ ! -z "$ST" ]; then
	sudo grep -F "$ST" /proc/net/ip_conntrack >> "$TMPF" || exit $?
else
	sudo cat /proc/net/ip_conntrack >> "$TMPF" || exit $?
fi

## split by comma
IFS=',' read -a CONTAINERS <<< "$CONTAINERS"

for CNAME in ${CONTAINERS[@]}; do
	for IMGCID in $(docker ps | awk '{ printf "%s=%s\n", $NF, $2}' | grep "^$CNAME"); do
		CID=$(echo "$IMGCID" | awk -F= '{ print $1} ')
		IMAGE=$(echo "$IMGCID" | awk -F= '{ print $2} '| awk -F/ '{ print $NF}')
		CIP=$(docker inspect --format='{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' $CID) || exit $?
		printf "%s\t%.${PAD}s\t\t%s\t" ${IPv4} $IMAGE $CID
		grep -F "src=$CIP" "$TMPF" | wc -l
	done
done | sort -V -k2

rm "$TMPF"