From 44e289f93bcf6d04c3eab231bac57dade06fc0c6 Mon Sep 17 00:00:00 2001
From: Franz Pletz <fpletz@fnordicwalking.de>
Date: Sun, 22 Sep 2019 17:14:47 +0200
Subject: [PATCH] nixos/stage-1: fix predictable interfaces names

This makes predictable interfaces names available as soon as possible
with udev by adding the default network link units to initrd which are read
by udev. Also adds some udev rules that are needed but which would normally
loaded from the udev store path which is not included in the initrd.
---
 nixos/modules/system/boot/stage-1-init.sh   |  6 ++++--
 nixos/modules/system/boot/stage-1.nix       | 15 +++++++++++++--
 nixos/tests/predictable-interface-names.nix |  6 ++++++
 3 files changed, 23 insertions(+), 4 deletions(-)

diff --git a/nixos/modules/system/boot/stage-1-init.sh b/nixos/modules/system/boot/stage-1-init.sh
index 8736613c3d2..607aec87f01 100644
--- a/nixos/modules/system/boot/stage-1-init.sh
+++ b/nixos/modules/system/boot/stage-1-init.sh
@@ -210,6 +210,8 @@ done
 # Create device nodes in /dev.
 @preDeviceCommands@
 echo "running udev..."
+mkdir -p /etc/systemd
+ln -sfn @linkUnits@ /etc/systemd/network
 mkdir -p /etc/udev
 ln -sfn @udevRules@ /etc/udev/rules.d
 mkdir -p /dev/.mdadm
@@ -266,7 +268,7 @@ checkFS() {
         return 0
     fi
 
-    # Device might be already mounted manually 
+    # Device might be already mounted manually
     # e.g. NBD-device or the host filesystem of the file which contains encrypted root fs
     if mount | grep -q "^$device on "; then
         echo "skip checking already mounted $device"
@@ -351,7 +353,7 @@ mountFS() {
             elif [ "$fsType" = f2fs ]; then
                 echo "resizing $device..."
                 fsck.f2fs -fp "$device"
-                resize.f2fs "$device" 
+                resize.f2fs "$device"
             fi
             ;;
     esac
diff --git a/nixos/modules/system/boot/stage-1.nix b/nixos/modules/system/boot/stage-1.nix
index 4c2d130d5a5..26117cffeda 100644
--- a/nixos/modules/system/boot/stage-1.nix
+++ b/nixos/modules/system/boot/stage-1.nix
@@ -120,6 +120,7 @@ let
 
       # Copy udev.
       copy_bin_and_libs ${udev}/lib/systemd/systemd-udevd
+      copy_bin_and_libs ${udev}/lib/systemd/systemd-sysctl
       copy_bin_and_libs ${udev}/bin/udevadm
       for BIN in ${udev}/lib/udev/*_id; do
         copy_bin_and_libs $BIN
@@ -198,6 +199,14 @@ let
     ''; # */
 
 
+  linkUnits = pkgs.runCommand "link-units" {
+      allowedReferences = [ extraUtils ];
+      preferLocalBuild = true;
+    } ''
+      mkdir -p $out
+      cp -v ${udev}/lib/systemd/network/*.link $out/
+    '';
+
   udevRules = pkgs.runCommand "udev-rules" {
       allowedReferences = [ extraUtils ];
       preferLocalBuild = true;
@@ -208,7 +217,9 @@ let
 
       cp -v ${udev}/lib/udev/rules.d/60-cdrom_id.rules $out/
       cp -v ${udev}/lib/udev/rules.d/60-persistent-storage.rules $out/
+      cp -v ${udev}/lib/udev/rules.d/75-net-description.rules $out/
       cp -v ${udev}/lib/udev/rules.d/80-drivers.rules $out/
+      cp -v ${udev}/lib/udev/rules.d/80-net-setup-link.rules $out/
       cp -v ${pkgs.lvm2}/lib/udev/rules.d/*.rules $out/
       ${config.boot.initrd.extraUdevRulesCommands}
 
@@ -222,7 +233,7 @@ let
             --replace ${pkgs.lvm2}/sbin ${extraUtils}/bin \
             --replace ${pkgs.mdadm}/sbin ${extraUtils}/sbin \
             --replace ${pkgs.bash}/bin/sh ${extraUtils}/bin/sh \
-            --replace ${udev}/bin/udevadm ${extraUtils}/bin/udevadm
+            --replace ${udev} ${extraUtils}
       done
 
       # Work around a bug in QEMU, which doesn't implement the "READ
@@ -257,7 +268,7 @@ let
       ${pkgs.buildPackages.busybox}/bin/ash -n $target
     '';
 
-    inherit udevRules extraUtils modulesClosure;
+    inherit linkUnits udevRules extraUtils modulesClosure;
 
     inherit (config.boot) resumeDevice;
 
diff --git a/nixos/tests/predictable-interface-names.nix b/nixos/tests/predictable-interface-names.nix
index 83883477a5c..bab091d57ac 100644
--- a/nixos/tests/predictable-interface-names.nix
+++ b/nixos/tests/predictable-interface-names.nix
@@ -17,6 +17,12 @@ in pkgs.lib.listToAttrs (pkgs.lib.crossLists (predictable: withNetworkd: {
       networking.useNetworkd = withNetworkd;
       networking.dhcpcd.enable = !withNetworkd;
       networking.useDHCP = !withNetworkd;
+
+      # Check if predictable interface names are working in stage-1
+      boot.initrd.postDeviceCommands = ''
+        ip link
+        ip link show eth0 ${if predictable then "&&" else "||"} exit 1
+      '';
     };
 
     testScript = ''