Handle new 'predictable' network interface naming style

[dougneal]

Explicitly discover the names of the ethernet interfaces, and don't assume that they are eth0, eth1 etc as this does not hold true under newer systemd-based distributions.

Addresses: #7155 #6871

[cnk]

I would love to be able to try this out; it looks like it fixes a number of the issues I am having building an Ubuntu 16.04 LTS dev VM.

Where do the scripts live to build a binary release locally? I tried building the vagrant gem from source and installing it along with its dependencies. But when I run it, I just get the 'vagrant doesn't run as a gem anymore' warnings.

[dougneal]

Hey @cnk - not sure on the process for doing a local build but you should be able to run it from the checked out source tree: https://github.com/mitchellh/vagrant/wiki/Installing-Vagrant-from-Source

[cnk]

Yeh I figured that out. I still need to figure out how to run with a salt provisioner.

@dougneal I am still getting the error from sudo hostname -f not resolving. So I will have to do some more poking around.

[dougneal]

I ran into that too, it's because the image doesn't have libnss-myhostname. Try the boxcutter/ubuntu1604 image for now, it seems to work better!

[caldwell]

I'm not sure this is technically correct. My systemd based machine (though not Ubuntu) has an ethernet adapter named enp0s31f6. This wouldn't be caught by this RE.

[geerlingguy]

This would only be for debian-based guests... is your machine running a Debian derivative, or something else (e.g. RHEL)?

[caldwell]

Debian GNU/Linux stretch/sid

[caldwell]

The name format appears to be described in systemd's udev-builtin-net_id.c

[ahrenstein]

+1 for this fix

[geerlingguy]

Here's a workaround for those interested in getting a Xenial base box working prior to this PR getting pulled in: geerlingguy/packer-boxes#1 (comment)

[krzysbaranski]

for now I use the following script in ubuntu/xenial64, after that I can reload box with provisioning

  # fix hosts ubuntu/xenial
  echo 127.0.0.1 `hostname` |sudo tee -a /etc/hosts

  # fix network ubuntu/xenial
  # disable Predictable Network Interface Names
  ip a show dev eth1 > /dev/null
  if (($? > 0)); then
    echo "#### eth1 not exists (eth1 and eth2 is expected by vagrant)"
    echo "#### turning off Predictable Network Interface Names"
    grep -q "net.ifnames=0" /etc/default/grub
    if (($? > 0)); then
      echo "GRUB_CMDLINE_LINUX=\"net.ifnames=0"\" | sudo tee -a /etc/default/grub
      sudo update-grub
      echo "#### restart box to disable Predictable Network Interface Names"
    fi
  fi

[hnakamur]

I created a simpler pull request #7253 to fix this issue and also a patch to vagrant 1.8.1 #7253 (comment)

[domnulnopcea]

when is this going to be merged?

[sebi-hgdata]

Just tested it out with

Vagrant.configure(2) do |config|
  config.vm.box = "ubuntu/xenial64"

  config.vm.provider "virtualbox" do |v|
    v.memory = 1024
    v.cpus = 1
  end

  config.vm.define "b1" do |b1|
    b1.vm.network "private_network", ip: "192.168.33.2"
  end

end

and it works.