From fec77a44b5a028ae1e5e3c7930cee9cb46977699 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Tue, 7 Mar 2023 22:02:24 +0000
Subject: [PATCH] DRY loopback interface, it's the same everywhere

---
 extneder.nix                  | 44 +++++++++--------------------------
 modules/base.nix              | 14 +++++++++++
 rotuer.nix                    | 12 +---------
 tests/pppoe/configuration.nix | 12 +---------
 tests/wlan/configuration.nix  | 10 +-------
 vanilla-configuration.nix     | 11 ++-------
 6 files changed, 30 insertions(+), 73 deletions(-)

diff --git a/extneder.nix b/extneder.nix
index 7c5a57c..b651c03 100644
--- a/extneder.nix
+++ b/extneder.nix
@@ -24,28 +24,6 @@
   inherit (pkgs) dropbear ifwait serviceFns
     ;
 in rec {
-  services.loopback = let
-    iface = interface {
-      type = "loopback";
-      device = "lo";
-    };
-  in
-    bundle {
-      name = "loopback";
-      contents = [
-        (address iface {
-          family = "inet4";
-          address = "127.0.0.1";
-          prefixLength = 8;
-        })
-        (address iface {
-          family = "inet6";
-          address = "::1";
-          prefixLength = 128;
-        })
-      ];
-    };
-
   boot = {
     tftp = {
       enable = true;
@@ -177,17 +155,17 @@ in rec {
 
   services.default = target {
     name = "default";
-    contents = with services; [
-      loopback
-      config.hardware.networkInterfaces.eth
-      config.hardware.networkInterfaces.wlan
-      int
-      bridge
-      hostap
-      defaultroute4
-      # resolvconf
-      sshd
-    ];
+    contents =
+      let links = config.hardware.networkInterfaces;
+      in with services; [
+        links.lo links.eth links.wlan
+        int
+        bridge
+        hostap
+        defaultroute4
+        # resolvconf
+        sshd
+      ];
   };
   defaultProfile.packages = with pkgs; [nftables strace tcpdump swconfig];
 }
diff --git a/modules/base.nix b/modules/base.nix
index e0b8656..ed8811b 100644
--- a/modules/base.nix
+++ b/modules/base.nix
@@ -3,6 +3,8 @@ let
   inherit (lib) mkEnableOption mkOption types isDerivation hasAttr ;
   inherit (pkgs.pseudofile) dir symlink;
   inherit (pkgs) busybox;
+  inherit (pkgs.liminix.networking) address interface;
+  inherit (pkgs.liminix.services) bundle;
 
   type_service = types.package // {
     name = "service";
@@ -46,6 +48,18 @@ in {
     defaultProfile.packages = with pkgs;
       [ s6 s6-init-bin busybox execline s6-linux-init s6-rc ];
 
+    hardware.networkInterfaces = {
+      lo =
+        let iface = interface { type = "loopback"; device = "lo";};
+        in bundle {
+          name = "loopback";
+          contents = [
+            (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
+            (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
+          ];
+        };
+    };
+
     kernel = rec {
       config = {
         IKCONFIG = "y";
diff --git a/rotuer.nix b/rotuer.nix
index 660d5e6..e777a64 100644
--- a/rotuer.nix
+++ b/rotuer.nix
@@ -22,16 +22,6 @@ let
     ifwait
     serviceFns;
 in rec {
-  services.loopback =
-    let iface = interface { type = "loopback"; device = "lo";};
-    in bundle {
-      name = "loopback";
-      contents = [
-        (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
-        (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
-      ];
-    };
-
   boot = {
     tftp = {
       enable = true;
@@ -221,7 +211,7 @@ in rec {
   services.default = target {
     name = "default";
     contents = with services; [
-      loopback
+      config.hardware.networkInterfaces.lo
       config.hardware.networkInterfaces.lan
       int
       bridge
diff --git a/tests/pppoe/configuration.nix b/tests/pppoe/configuration.nix
index c6fa632..c9601ae 100644
--- a/tests/pppoe/configuration.nix
+++ b/tests/pppoe/configuration.nix
@@ -3,16 +3,6 @@ let
   inherit (pkgs.liminix.networking) interface address pppoe route dnsmasq;
   inherit (pkgs.liminix.services) oneshot longrun bundle target output;
 in rec {
-  services.loopback =
-    let iface = interface { type = "loopback"; device = "lo";};
-    in bundle {
-      name = "loopback";
-      contents = [
-        (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
-        (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
-      ];
-    };
-
   services.lan4 =
     let iface = interface { type = "hardware"; device = "eth1";};
     in address iface { family = "inet4"; address ="192.168.19.1"; prefixLength = 24;};
@@ -75,7 +65,7 @@ in rec {
   services.default = target {
     name = "default";
     contents = with services; [
-      loopback
+      config.hardware.networkInterfaces.lo
       defaultroute4
       packet_forwarding
       dns
diff --git a/tests/wlan/configuration.nix b/tests/wlan/configuration.nix
index 91300ae..1148e4d 100644
--- a/tests/wlan/configuration.nix
+++ b/tests/wlan/configuration.nix
@@ -3,15 +3,7 @@ let
   inherit (pkgs.liminix.networking) interface address hostapd route dnsmasq;
   inherit (pkgs.liminix.services) oneshot longrun bundle target;
 in rec {
-  services.loopback =
-    let iface = interface { type = "loopback"; device = "lo";};
-    in bundle {
-      name = "loopback";
-      contents = [
-        (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
-        (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
-      ];
-    };
+  services.loopback = config.hardware.networkInterfaces.lo;
 
   imports = [ ../../modules/wlan.nix ];
 
diff --git a/vanilla-configuration.nix b/vanilla-configuration.nix
index e37fbff..1b88f63 100644
--- a/vanilla-configuration.nix
+++ b/vanilla-configuration.nix
@@ -7,15 +7,8 @@ in rec {
     ./modules/tftpboot.nix
     ./modules/wlan.nix
   ];
-  services.loopback =
-    let iface = interface { type = "loopback"; device = "lo";};
-    in bundle {
-      name = "loopback";
-      contents = [
-        (address iface { family = "inet4"; address ="127.0.0.1"; prefixLength = 8;})
-        (address iface { family = "inet6"; address ="::1"; prefixLength = 128;})
-      ];
-    };
+  services.loopback = config.hardware.networkInterfaces.lo;
+
   services.dhcpv4 =
     let iface = interface { type = "hardware"; device = "eth0"; };
     in udhcpc iface {};