For the vagrant instance we use the `bento/ubuntu-16.04` boxes, which receive periodic updates, that are pulled down either when someone opts into an update on their machine, or if no earlier version of the image already existed (eg a contributor starting out): https://app.vagrantup.com/bento/boxes/ubuntu-16.04 It turns out that the recent release of this image has renamed the network interface yet again (pre-Xenial used `eth0`, then Ubuntu renamed it to ``, then bento have reverted that to `eth0`), breaking the iptables commands we use to allow external connections to reach the servers bound to 127.0.0.1. This change occurred in: https://github.com/chef/bento/pull/900 I've found a way to calculated the interface name dynamically, so the iptable command will work no matter what version of the box image people happen to have on their machine. Longer term, moving to docker and having proper 0.0.0.0 bind options set in the RUN commands will mean we can avoid the iptables hack.

Commit pushed to master at https://github.com/mozilla/treeherder https://github.com/mozilla/treeherder/commit/c9500cf3d239113eb5d777e1dd0f9e035111bf07 Bug 1417099 - Vagrant: Fix networking when using latest Bento images (#2945) The bento image has renamed the network interface from `enp0s3` back to `eth0`, effectively reverting the upstream Ubuntu 16.04 "predictable network interface names" feature. We now have to calculate the name dynamically, since we don't know which version of the bento image will be installed locally when people use the Treeherder Vagrant environment.