Export envvars from docker-like envvar file

export_envvars.sh

#!/bin/bash

# As seen here https://stackoverflow.com/questions/2683279/how-to-detect-if-a-script-is-being-sourced
if [[ $0 == $BASH_SOURCE ]]; then
	echo 'You must run this script as `source export_envvars.sh` for it to export the envvars.'
else
  if [[ -z $1 ]]; then
    echo 'You must provide name of the envvars file.'
  else
  	# As seen here http://stackoverflow.com/questions/10929453/read-a-file-line-by-line-assigning-the-value-to-a-variable
  	# Read all the stuff from envvars file and echo it
  	while read -r line || [[ -n $line ]]
  	do
  	  envvar="$line"
  		if [[ -n "$envvar" ]]; then
  	    export "$envvar"
  	  fi
  	done < "$1"
  fi
fi