I made a basic script that uses debmirror to mirror ROS packages onto a local server to improve download times when setting up a bunch of robots.
I like debmirror a bit better than the apt-mirror based solution, as there is no configuration file, just a script that does the mirror. Also it looks like debmirror gives a bit more control over what gets mirrored.
Here is the script:
It downloads Ubuntu armhf packages for trusty (indigo and jade), and xenial (kinetic), but can be easily modified. (1.8GB)
Before running it, you will need to make a gpg keychain that trusts the ros key.
gpg --no-default-keyring --keyring /home/ubuntu/mirrorkeyring/trustedkeys.gpg --import ./ros.key
The script can be run periodically in a cron job to keep the mirror up to date.