replace sed -i on /etc/hosts by simple sed with cp

Hello, there is a problem on Docker to use "sed -i" on /etc/hosts file, because it's mouted on other fs.
However, it's possible to use simple sed with tempory file and cp / rm.
Thanks

Ref from Docker documentation : https://docs.docker.com/v1.3/userguide/dockervolumes/
Note: Many tools used to edit files including vi and sed --in-place may result in an inode change. Since Docker v1.1.0, this will produce an error such as "sed: cannot rename ./sedKdJ9Dy: Device or resource busy". In the case where you want to edit the mounted file, it is often easiest to instead mount the parent directory.