From 9f468d2626447d6f32ba4cfebf1837a6d343211d Mon Sep 17 00:00:00 2001
From: Chris Roberts <code@chrisroberts.org>
Date: Thu, 29 Sep 2016 15:33:29 -0700
Subject: [PATCH 1/2] guests/linux: Place ethernet devices at start of device
 list

---
 plugins/guests/linux/cap/network_interfaces.rb | 18 ++++++++++++++++++
 .../linux/cap/network_interfaces_test.rb       | 13 +++++++++++++
 2 files changed, 31 insertions(+)

diff --git a/plugins/guests/linux/cap/network_interfaces.rb b/plugins/guests/linux/cap/network_interfaces.rb
index 8a4c64dd3..ea7dc32da 100644
--- a/plugins/guests/linux/cap/network_interfaces.rb
+++ b/plugins/guests/linux/cap/network_interfaces.rb
@@ -2,6 +2,11 @@ module VagrantPlugins
   module GuestLinux
     module Cap
       class NetworkInterfaces
+        # Valid ethernet device prefix values.
+        # eth - classic prefix
+        # en  - predictable interface names prefix
+        ETHERNET_PREFIX = ["eth", "en"]
+
         @@logger = Log4r::Logger.new("vagrant::guest::linux::network_interfaces")
 
         # Get network interfaces as a list. The result will be something like:
@@ -15,10 +20,16 @@ module VagrantPlugins
             s << data if type == :stdout
           end
           ifaces = s.split("\n")
+          eth_prefix = nil
           @@logger.debug("Unsorted list: #{ifaces.inspect}")
           # Break out integers from strings and sort the arrays to provide
           # a natural sort for the interface names
           ifaces = ifaces.map do |iface|
+            unless eth_prefix
+              eth_prefix = ETHERNET_PREFIX.detect do |prefix|
+                iface.start_with?(prefix)
+              end
+            end
             iface.scan(/(.+?)(\d+)/).flatten.map do |iface_part|
               if iface_part.to_i.to_s == iface_part
                 iface_part.to_i
@@ -28,6 +39,13 @@ module VagrantPlugins
             end
           end.sort.map(&:join)
           @@logger.debug("Sorted list: #{ifaces.inspect}")
+          # Extract ethernet devices and place at start of list
+          if eth_prefix
+            eth_start = ifaces.index{|iface| iface.start_with?(eth_prefix) }
+            eth_end = ifaces.rindex{|iface| iface.start_with?(eth_prefix) }
+            ifaces.unshift(*ifaces.slice!(eth_start, eth_end - 1))
+            @@logger.debug("Ethernet preferred sorted list: #{ifaces.inspect}")
+          end
           ifaces
         end
       end
diff --git a/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb b/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
index 8dd4498a7..139cebfdc 100644
--- a/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
+++ b/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
@@ -44,5 +44,18 @@ describe "VagrantPlugins::GuestLinux::Cap::NetworkInterfaces" do
       result = cap.network_interfaces(machine)
       expect(result).to eq(["enp0s3", "enp0s5", "enp0s8", "enp0s10", "enp1s3"])
     end
+
+    it "sorts ethernet devices discovered with classic naming first in list" do
+      expect(comm).to receive(:sudo).and_yield(:stdout, "eth1\neth2\ndocker0\nbridge0\neth0")
+      result = cap.network_interfaces(machine)
+      expect(result).to eq(["eth0", "eth1", "eth2", "bridge0", "docker0"])
+    end
+
+    it "sorts ethernet devices discovered with predictable network interfaces naming first in list" do
+      expect(comm).to receive(:sudo).and_yield(:stdout, "enp0s8\ndocker0\nenp0s3\nbridge0\nenp0s5")
+      result = cap.network_interfaces(machine)
+      expect(result).to eq(["enp0s3", "enp0s5", "enp0s8", "bridge0", "docker0"])
+    end
+
   end
 end

From 0300df09fb3aa4f05cca754de10a828502bf0321 Mon Sep 17 00:00:00 2001
From: Chris Roberts <code@chrisroberts.org>
Date: Fri, 30 Sep 2016 12:11:54 -0700
Subject: [PATCH 2/2] guests/linux: Update constant name, freeze constant
 values

---
 plugins/guests/linux/cap/network_interfaces.rb              | 6 +++---
 .../plugins/guests/linux/cap/network_interfaces_test.rb     | 1 -
 2 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/plugins/guests/linux/cap/network_interfaces.rb b/plugins/guests/linux/cap/network_interfaces.rb
index ea7dc32da..6d3ce657c 100644
--- a/plugins/guests/linux/cap/network_interfaces.rb
+++ b/plugins/guests/linux/cap/network_interfaces.rb
@@ -5,7 +5,7 @@ module VagrantPlugins
         # Valid ethernet device prefix values.
         # eth - classic prefix
         # en  - predictable interface names prefix
-        ETHERNET_PREFIX = ["eth", "en"]
+        POSSIBLE_ETHERNET_PREFIXES = ["eth".freeze, "en".freeze].freeze
 
         @@logger = Log4r::Logger.new("vagrant::guest::linux::network_interfaces")
 
@@ -25,8 +25,8 @@ module VagrantPlugins
           # Break out integers from strings and sort the arrays to provide
           # a natural sort for the interface names
           ifaces = ifaces.map do |iface|
-            unless eth_prefix
-              eth_prefix = ETHERNET_PREFIX.detect do |prefix|
+            if eth_prefix.nil?
+              eth_prefix = POSSIBLE_ETHERNET_PREFIXES.detect do |prefix|
                 iface.start_with?(prefix)
               end
             end
diff --git a/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb b/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
index 139cebfdc..810606f2a 100644
--- a/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
+++ b/test/unit/plugins/guests/linux/cap/network_interfaces_test.rb
@@ -56,6 +56,5 @@ describe "VagrantPlugins::GuestLinux::Cap::NetworkInterfaces" do
       result = cap.network_interfaces(machine)
       expect(result).to eq(["enp0s3", "enp0s5", "enp0s8", "bridge0", "docker0"])
     end
-
   end
 end