Simple Log function in Bash

log.sh

# a simple log function in bash
# usage:
#   log "my info message"
#   log "my debug message" debug

log_level=info
# uncomment next line to rise up log level
#log_level=debug

log() {
   local msg=$1
   local level=${2:-info}
   if [[ $level == debug ]] && [[ $log_level != debug ]]; then
          return 0
   fi
   now=$(date --rfc-3339=seconds)
   echo "$now [$level] $msg" >> /dev/stderr
}