How to modify run options to a existing container?

I created a container and add a lot of work in it.Then I realized I forgot to do volume mapping with run option -v.
I want to add volume mapping in my existing container(NOT A NEW ONE).I’ve searched on google,but found nothing.

So how can I add volume mapping?

And this raises a more general question:
How to modify run options to a existing container?

I am afraid, you will not like the answer. Docker provides very limited update functionality for existing containers, see

Though, there might be some dirty ways to still get the data outside the container:
– you might get lucky with checking the subfolders of /var/lib/docker/container// and /var/lib/docker/volumes//_data and find the files there…
– you might use docker container cp to copy the data form the container to the hostl

If the image declared any volumes, you can exec into your container and copy the files to the folder declared as volume, and check /var/lib/docker/volumes/*/_data again OR create a new container where you use --volumes-from to mount all volumes from your first container and of course provide a volume mapping as the target to copy the files to the host…