#!/bin/bash
## docker-ports
##
## @author gdm85
## script to show docker allocated ports of a container
#

if ! type jq >/dev/null 2>/dev/null; then
	echo "jq must be installed" 1>&2
	exit 1
fi

if [ $# -lt 1 ]; then
	echo "Please specify at least one container" 1>&2
	exit 1
fi

function show_ports() {
	local CID="$1"

	local CONTAINER_IPv4=$(docker inspect --format '{{ .NetworkSettings.IPAddress }}' $CID) || return $?
	if [[ -z "$CONTAINER_IPv4" || "$CONTAINER_IPv4" == "<no value>" ]]; then
		echo "Invalid container: $CID" 1>&2
		return 1
	fi

	local NAME=$(docker inspect --format '{{ .Name }}' $CID | awk '{ print substr($0, 2, length($0)-1) }')

	local STANZA="$(docker inspect --format '{{json .HostConfig.PortBindings }}' $CID)" || return $?

	echo "$NAME:"

	let I=0
	for P in $(echo "$STANZA" | jq -M 'keys' | tail -n+2 | head -n-1 | sed s/,$// | sed 's/"//g' ); do
		## port on container
		local SRCPORT="$(echo $P | awk -F/ '{ print $1 }')"

		echo -e -n "\t$SRCPORT\t<-\t"

		## get port binding (if any)
		local SNIP=$(echo $STANZA | jq -M "to_entries | .[$I].value")

		if [[ -z "$SNIP" || "$SNIP" == "null" ]]; then
			echo "$CONTAINER_IPv4:$SRCPORT"
		else
			local HOSTIP="$(echo $SNIP | jq -M -r '.[0].HostIp')"

			## match only bindings on dockerhost
			if [[ -z "$HOSTIP" || "$HOSTIP" == '0.0.0.0' ]]; then
				local HOSTPORT="$(echo $SNIP | jq -M -r '.[0].HostPort')"
				echo "0.0.0.0:$HOSTPORT"
			else
				echo "$HOSTIP:$SRCPORT"
			fi
		fi
		let I=I+1
	done
}

for CID in $@; do
	show_ports "$CID"
done