Start a docker container with environment variables for external port and IP

run.sh

#!/bin/bash
#Start a docker container with environment variables for external port and IP

if [ -z $1 ]
then
	echo pass in starting port
	exit 1
fi

START_PORT=$1
MAX_PORT=$(($START_PORT+10))
# assumes datacenter IPs look like 10.x.y.z
HOST=$(ip addr | grep ' 10\.' | sed 's/.*\(10\..*\)\/.*/\1/')

for (( PORT=$START_PORT; $PORT <= $MAX_PORT; PORT++ ))
do
	MSG=$(docker run -e PORT_80_EXTERNAL=$PORT -e HOST_EXTERNAL=$HOST -v /var/tmp/:/usr/share/nginx/html:ro -d -p $PORT:80 nginx 2>&1)
	RES=$?
	echo $MSG | grep 'port is already allocated' > /dev/null
	PORT_ISSUE=$?
	#echo res $RES msg $MSG port issue $PORT_ISSUE
	if [ $RES -eq 0 ]
	then
		echo successfully started on external port $PORT on host $HOST
		exit 0
	fi
	if [ $PORT_ISSUE -ne 0 ] && [ $RES -ne 0 ]
	then
		echo error starting docker!
		exit $RES
	fi
done
echo found no free port between $START_PORT and $MAX_PORT
exit 1