Are you trying to mount a directory onto a file (or vice-versa)?

I have a docker with version 17.06.0-ce. When I trying to install NGINX using docker with command:

docker run -p 80:80 -p 8080:8080 --name nginx -v $PWD/www:/www -v $PWD/conf/nginx.conf:/etc/nginx/nginx.conf -v $PWD/logs:/wwwlogs -d nginx:latest

It shows that

docker: Error response from daemon: oci runtime error: container_linux.go:262: starting container process caused "process_linux.go:339: container init caused "rootfs_linux.go:57: mounting \"/appdata/nginx/conf/nginx.conf\" to rootfs \"/var/lib/docker/aufs/mnt/dcea22444e9ffda114593b18fc8b574adfada06947385aedc2ac09f199188fa0\" at \"/var/lib/docker/aufs/mnt/dcea22444e9ffda114593b18fc8b574adfada06947385aedc2ac09f199188fa0/etc/nginx/nginx.conf\" caused \"not a directory\""" : Are you trying to mount a directory onto a file (or vice-versa)? Check if the specified host path exists and is the expected type.

If do not mount the nginx.conf file, everything is okay. So, how can I mount the configuration file?