Script bash para executar comando em um container de php71

php71.sh

#
# uso: php71 /var/www/html/foo composer install
#
#!/bin/bash

path=$1
args=("$@")
unset args[0]

if [ -z "$path" ]
  then
    path=$(pwd)
fi

container=$PHP71_CONTAINER

if [ -z "$PHP71_CONTAINER" ]
  then
    container="php71-apache_php71_1"
fi

docker exec -it -w $path $container ${args[@]}