support dhcp static leases

THOUGHTS.txt

@@ -2141,8 +2141,8 @@ Thu Aug 31 23:53:54 BST 2023
   - packet forwarding
 - and arhcive
   - rsync
-  - watchdog
-  - mount
+  - [done] watchdog
+  - [done] mount
 - nftables syntax error
 - tidy up the dependency handling in serviceDefn build
    (interface is fine, implementation is a bit brutal)
@@ -2151,3 +2151,99 @@ Thu Aug 31 23:53:54 BST 2023
 - [done] ntp is not setting the time
 - static dhcp(6) lease support reqd for dogfooding
 
+Sat Sep  2 21:35:41 BST 2023
+
+Considerations for "mount" service: each filesystem needs to depend on
+any mount points for its parent directories, and maybe also on other
+services (e.g. filesystem modules, network devices, routes)
+
+mountpoints = {
+ mnt = {
+   media = svc.mountpoint.build {
+     fstype = "msdos";
+     device = "/dev/sda1";
+     options = [ ...];
+   };
+   archive = svc.mountpoint.build {
+     fstype = "ext4";
+     device = "/dev/sda2";
+     options = [ ...];
+     mountpoints = {
+       remote = svc.mountpoint.build {
+         fstype = "nfs";
+	 device = "doc.ic.ac.uk:/public";
+       };
+     };
+   };
+  };
+}
+
+services.somethingelse = svc.ftpd.build {
+  # ...
+  dependencies = [ mountpoints.mnt.archive ];
+}
+
+what don't we like about this? we have to walk the nested attrset in a
+weird way, because the services may contain other mountpoints. Maybe
+just keep it simple and do
+
+
+services.mountpoints = bundle {
+ name = "mountpoints";
+ contents = [
+   svc.mountpoint.build {
+     device = "/dev/sda2"; fstype = "ext4"; directory = "/mnt/isos";
+   };
+   svc.mountpoint.build {
+     device = "/dev/sdb1"; fstype = "msdos"; directory = "/mnt/backup";
+     dependencies = [ load-vfat-module ];
+   };
+ ];
+}
+
+Sun Sep  3 17:34:36 BST 2023
+
+how to dogfood
+
+DHCP6 server: static lease support
+DHCP client and acquire-{lan-prefix,wan-address}
+
+The emergency boot thingy in glinet u-boot won't help because it
+expects to flash from its tftp request instead of booting it. So we
+could use kexec instead except that the openwrt install doesn't have
+it.  So we could swap the hardware devices, the only downside of that
+being that then I don't have a test system any more. Or we could YOLO it.
+
+Sun Sep  3 22:11:02 BST 2023
+
+I think we should rejigger the documentation ...
+
+- "getting started": worked example, building and installing Liminix
+with a very simple config (wifi AP with ssh daemon)
+
+- using modules
+  - link to module reference
+
+- creating custom services
+  - longrun or oneshot
+  - dependencies
+  - outputs
+
+- creating your own modules
+
+- hacking on Liminix itself
+
+- contributing
+
+- external links and resources
+
+- module reference
+
+- hardware device reference
+
+---
+
+I think we might rename wlan_24 to wlan and wlan_5 to wlan1.
+This is on the assumption that almost no device is 5GHz only, so
+would make it easier to write a basic wlan example that works
+both on 2.4GHz boards and dual radio boards

examples/arhcive.nix

@@ -30,6 +30,7 @@ in rec {
     ../modules/vlan
     ../modules/ssh
     ../modules/watchdog
+    ../modules/mount
   ];
 
   hostname = "arhcive";
@@ -101,27 +102,18 @@ in rec {
   };
 
   programs.busybox  = {
-    applets = ["blkid" "lsusb" "findfs" "tar"];
+    applets = ["lsusb" "tar"];
     options = {
       FEATURE_LS_TIMESTAMPS = "y";
       FEATURE_LS_SORTFILES = "y";
-      FEATURE_BLKID_TYPE = "y";
-      FEATURE_MOUNT_FLAGS = "y";
-      FEATURE_MOUNT_LABEL = "y";
       FEATURE_VOLUMEID_EXT = "y";
     };
   };
 
-  services.mount_external_disk = oneshot {
-    name = "mount_external_disk";
-    up = ''
-      while ! findfs LABEL=backup-disk; do
-        echo waiting for backup-disk
-        sleep 1
-      done
-      mount -t ext4 LABEL=backup-disk /srv
-    '';
-    down = "umount /srv";
+  services.mount_external_disk = svc.mount.build {
+    device = "LABEL=backup-disk";
+    mountpoint = "/srv";
+    fstype = "ext4";
   };
 
   services.rsync =

examples/rotuer.nix

@@ -9,13 +9,8 @@
 { config, pkgs, lib, ... } :
 let
   secrets = import ./rotuer-secrets.nix;
-  inherit (pkgs.liminix.services) oneshot longrun bundle target;
-  inherit (pkgs)
-    dropbear
-    ifwait
-    writeText
-    writeFennelScript
-    serviceFns;
+  inherit (pkgs.liminix.services) oneshot longrun;
+  inherit (pkgs) serviceFns;
   svc = config.system.service;
   wirelessConfig =  {
     country_code = "GB";
@@ -131,6 +126,7 @@ in rec {
       rm -rf /run/service-state/${name}/
     '';
   };
+
   filesystem =
     let inherit (pkgs.pseudofile) dir symlink;
     in dir {
@@ -139,7 +135,6 @@ in rec {
       };
     };
 
-
   services.defaultroute4 = svc.network.route.build {
     via = "$(output ${services.wan} address)";
     target = "default";

modules/dnsmasq/default.nix

@@ -42,6 +42,37 @@ in {
       ranges = mkOption {
         type = types.listOf types.str;
       };
+      hosts = mkOption {
+        type = types.attrsOf (types.submodule {
+          options = {
+            mac = mkOption {
+              description = ''
+                MAC or other hardware address to match on. For Ethernet
+                this is a 48 bit address represented as colon-separated
+                hex bytes, or "id:clientid" to match a presented
+                client id (IPv6 DUID)
+              '';
+              type = types.str;
+              example = "01:20:31:4a:50";
+            };
+            v4 = mkOption  {
+              description = "IPv4 address to assign to this client";
+              example = "192.0.2.1";
+              type = types.str;
+            };
+            v6 = mkOption  {
+              type = types.listOf types.str;
+              description = "IPv6 addresses or interface-ids to assign to this client";
+              default = [];
+              example = [ "fe80::42:1eff:fefd:b341" "::1234"];
+            };
+            leasetime = mkOption {
+              type = types.int;
+              default = 86400;
+            };
+          };
+        });
+      };
       domain = mkOption {
         # this can be given multiple times so probably should be
         # domains plural and list of string

modules/dnsmasq/service.nix

@@ -10,13 +10,17 @@
 , domain
 , group
 , ranges
+, hosts
 , upstreams
 , resolvconf
 }:
 let
   name = "${interface.name}.dnsmasq";
   inherit (liminix.services) longrun;
-  inherit (lib) concatStringsSep;
+  inherit (lib) concatStrings concatStringsSep mapAttrsToList;
+  hostOpt = name : { mac, v4, v6, leasetime } @ attrs:
+    let v6s = concatStrings (map (a : ",[${a}]") v6);
+    in "--dhcp-host=${mac},${v4}${v6s},${name},${builtins.toString leasetime}";
 in
 longrun {
   inherit name;
@@ -33,6 +37,7 @@ longrun {
     --keep-in-foreground \
     --dhcp-authoritative \
     ${if resolvconf != null then "--resolv-file=$(output_path ${resolvconf} resolv.conf)" else "--no-resolv"} \
+    ${lib.concatStringsSep " " (mapAttrsToList hostOpt hosts)} \
     --no-hosts \
     --log-dhcp \
     --enable-ra \

modules/mount/default.nix

@@ -0,0 +1,49 @@
+
+{ lib, pkgs, config, ...}:
+let
+  inherit (lib) mkOption types;
+  inherit (pkgs) liminix;
+  mkBoolOption = description : mkOption {
+    type = types.bool;
+    inherit description;
+    default = true;
+  };
+
+in {
+  options = {
+    system.service.mount = mkOption {
+      type = liminix.lib.types.serviceDefn;
+    };
+  };
+  config.system.service = {
+    mount = liminix.callService ./service.nix {
+      device = mkOption {
+        type = types.str;
+        example = "/dev/sda1";
+      };
+      mountpoint = mkOption {
+        type = types.str;
+        example = "/mnt/media";
+      };
+      options = mkOption {
+        type = types.listOf types.str;
+        default = [];
+        example = ["noatime" "ro" "sync"];
+      };
+      fstype = mkOption {
+        type = types.str;
+        default = "auto";
+        example = "vfat";
+      };
+    };
+  };
+  config.programs.busybox  = {
+    applets = ["blkid" "findfs"];
+    options = {
+      FEATURE_BLKID_TYPE = "y";
+      FEATURE_MOUNT_FLAGS = "y";
+      FEATURE_MOUNT_LABEL = "y";
+      FEATURE_VOLUMEID_EXT = "y";
+    };
+  };
+}

modules/mount/service.nix

@@ -0,0 +1,18 @@
+{
+  liminix
+, lib
+}:
+{ device, mountpoint, options, fstype }:
+let
+  inherit (liminix.services) oneshot;
+in oneshot {
+  name = "mount.${lib.escapeURL mountpoint}";
+  up = ''
+    while ! findfs ${device}; do
+      echo waiting for device ${device}
+      sleep 1
+    done
+    mount -t ${fstype} -o ${lib.concatStringsSep "," options} ${device} ${mountpoint}
+  '';
+  down = "umount ${mountpoint}";
+}