From 4795dd05b79c3bd18f2909faa8baf9cd559864d8 Mon Sep 17 00:00:00 2001
From: Daniel Barlow <dan@telent.net>
Date: Wed, 3 Apr 2024 23:07:56 +0100
Subject: [PATCH] unconditionally restart trigger services on liminix-rebuild

We call s6-rc -u -p default to restart/start the base services
on a rebuild, otherwise services that are only in the new
configuration won't come up. However, this stops any service
started by a trigger. So, workaround is to restart the trigger
service and expect it to restart the services it manages if they're
needed
---
 modules/ifwait/ifwait.nix               | 1 +
 pkgs/liminix-tools/services/builder.sh  | 2 +-
 pkgs/liminix-tools/services/default.nix | 2 ++
 pkgs/s6-rc-database/default.nix         | 9 +++++++--
 pkgs/systemconfig/restart-services.fnl  | 7 +++++--
 5 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/modules/ifwait/ifwait.nix b/modules/ifwait/ifwait.nix
index 4c28b52..ee5d957 100644
--- a/modules/ifwait/ifwait.nix
+++ b/modules/ifwait/ifwait.nix
@@ -9,6 +9,7 @@ let
 in longrun {
   name = "ifwait.${interface.name}";
   buildInputs = [ service ];
+  isTrigger = true;
   run = ''
     ${ifwait}/bin/ifwait -s ${service.name}  $(output ${interface} ifname) ${state}
   '';
diff --git a/pkgs/liminix-tools/services/builder.sh b/pkgs/liminix-tools/services/builder.sh
index 744a86e..5edfa5d 100644
--- a/pkgs/liminix-tools/services/builder.sh
+++ b/pkgs/liminix-tools/services/builder.sh
@@ -11,7 +11,7 @@ test -n "$contents" && for d in $contents; do
     touch $out/${name}/contents.d/$d
 done
 
-for i in timeout-up timeout-down run notification-fd up down consumer-for producer-for pipeline-name ; do
+for i in timeout-up timeout-down run notification-fd up down consumer-for producer-for pipeline-name restart-on-upgrade; do
     test -n "$(printenv $i)" && (echo "$(printenv $i)" > $out/${name}/$i)
 done
 
diff --git a/pkgs/liminix-tools/services/default.nix b/pkgs/liminix-tools/services/default.nix
index 881fea0..34c9b7e 100644
--- a/pkgs/liminix-tools/services/default.nix
+++ b/pkgs/liminix-tools/services/default.nix
@@ -36,12 +36,14 @@ let
     , dependencies ? []
     , contents ? []
     , buildInputs ? []
+    , isTrigger ? false
   } @ args:
     stdenvNoCC.mkDerivation {
       # we use stdenvNoCC to avoid generating derivations with names
       # like foo.service-mips-linux-musl
       inherit name serviceType up down run notification-fd
         producer-for consumer-for pipeline-name timeout-up timeout-down;
+      restart-on-upgrade = isTrigger;
       buildInputs = buildInputs ++ dependencies ++ contents;
       dependencies = builtins.map (d: d.name) dependencies;
       contents = builtins.map (d: d.name) contents;
diff --git a/pkgs/s6-rc-database/default.nix b/pkgs/s6-rc-database/default.nix
index 1fabe41..49ef99c 100644
--- a/pkgs/s6-rc-database/default.nix
+++ b/pkgs/s6-rc-database/default.nix
@@ -21,11 +21,16 @@ in stdenvNoCC.mkDerivation  {
       if test -d $i; then
         for j in $i/* ; do
           if test -f $j/type ; then
+            if test -e $j/restart-on-upgrade; then
+              flag=force-restart
+            else
+              unset flag
+            fi
             case $(cat $j/type) in
               longrun|oneshot)
-                # s6-rc-update only wants oneshots in its
+                # s6-rc-update only wants atomics in its
                 # restarts file
-                echo $(basename $j) " " $i >>  $out/hashes
+                echo $(basename $j) " " ''${flag-$i} >>  $out/hashes
                 ;;
               *)
                 ;;
diff --git a/pkgs/systemconfig/restart-services.fnl b/pkgs/systemconfig/restart-services.fnl
index 04c3300..69a5452 100644
--- a/pkgs/systemconfig/restart-services.fnl
+++ b/pkgs/systemconfig/restart-services.fnl
@@ -12,8 +12,11 @@
         new-hashes (hashes-from-file new)]
     (with-open [f (io.open "/tmp/restarts" :w)]
       (each [n h (pairs old-hashes)]
-        (when (not (= h (. new-hashes n)))
-          (f:write (.. n " restart\n")))))))
+        (let [new (. new-hashes n)]
+          (when (or (= h "force-restart")
+                    (= new "force-restart")
+                    (not (= h new)))
+            (f:write (.. n " restart\n"))))))))
 
 (fn exec [text command]
   (io.write (.. text ": "))