How to edit config files in docker container?

I'm running DVWA on a container and I want to change the configuration files of php to allow_url_include option that is disabled by default. I tried to run sudo docker run -t -i my_image /bin/bash and edit files manually. Later on I realized that despite of my editings docker daemon always overwrites them. So I tried to use RUN command in Dockerfile when building the image. Without any sucess. Any thoughts on this?