message: define defaults in the dockerfile for username and password.
diff: @@ -17,8 +17,8 @@ ENV RABBITMQ_HOST="rabbitmq" \
  RABBITMQ_USER="guest" \
  RABBITMQ_PASSWORD="guest" \
  ELASTICSEARCH_URL="http://logs-db:9200" \
  - LOGSTASH_USERNAME="$LOGSTASH_USERNAME" \
  - LOGSTASH_PASSWORD="$LOGSTASH_PASSWORD"
  + LOGSTASH_USERNAME="username" \
  + LOGSTASH_PASSWORD="password"
  ENV XPACK_MONITORING_ELASTICSEARCH_URL=$ELASTICSEARCH_URL
  EXPOSE 8080 9600
  