From 8bedc860aef192d1dbdc0d8669e92dd4f2aa7e12 Mon Sep 17 00:00:00 2001
From: Colin <colin@uninsane.org>
Date: Tue, 19 Mar 2024 06:50:03 +0000
Subject: [PATCH] s6: add some minimal logging

the root s6 call seems to be doing some logging, notably feedbackd; still don't know where the other logs are going
---
 modules/users/s6-rc.nix | 77 +++++++++++++++++++++++------------------
 1 file changed, 43 insertions(+), 34 deletions(-)

diff --git a/modules/users/s6-rc.nix b/modules/users/s6-rc.nix
index 63e2be88..e3b632b2 100644
--- a/modules/users/s6-rc.nix
+++ b/modules/users/s6-rc.nix
@@ -1,20 +1,18 @@
 { lib, pkgs, ... }:
 let
+  logBase = "$HOME/.local/state/s6/logs";
   normalizeName = name: lib.removeSuffix ".service" (lib.removeSuffix ".target" name);
 
   # infers the service type from the arguments and dispatches appropriately
-  genService = { name, run, depends }: if run != null then
-    genService' (normalizeName name) "longrun" depends [
-      (pkgs.writeTextFile {
-        name = "s6-${name}-run";
-        destination = "/${normalizeName name}/run";
-        executable = true;
-        # TODO: consider using `makeWrapper`/`makeWrapperBin`?
-        text = ''
-          #!/bin/sh
-          exec ${run}
-        '';
-      })
+  genService = { name, run, depends }: let
+    name' = normalizeName name;
+    logDir = "${logBase}/${name'}";
+    # N.B. s6-log will create the logDir. at least, if the parent dir exists (haven't tested without that)
+    logger = genRun "${name'}/log" ''s6-log -- T "${logDir}"'';
+  in if run != null then
+    genService' name' "longrun" depends [
+      (genRun name' run)
+      logger
     ]
   else
     # TODO: a bundle can totally have dependencies. i can't just map them *all* to contents.
@@ -33,10 +31,10 @@ let
     #     '')
     #   ]
     # )
-    genService' (normalizeName name) "bundle" [] [
+    genService' name' "bundle" [] [
       (pkgs.writeTextFile {
-        name = "s6-${name}-contents";
-        destination = "/${normalizeName name}/contents";
+        name = "s6-${name'}-contents";
+        destination = "/${name'}/contents";
         text = lib.concatStringsSep "\n" (builtins.map normalizeName depends);
       })
     ]
@@ -58,6 +56,17 @@ let
       depends;
   };
 
+  genRun = serviceName: shellCommand: pkgs.writeTextFile {
+    name = "s6-${serviceName}-run";
+    destination = "/${serviceName}/run";
+    executable = true;
+    # TODO: consider using `makeWrapper`/`makeBinaryWrapper`?
+    text = ''
+      #!/bin/sh
+      exec ${shellCommand} 2>&1
+    '';
+  };
+
   # create a directory, containing N subdirectories:
   # - svc-a/
   #   - type
@@ -139,37 +148,37 @@ in
         function startS6() {
           local S6_TARGET="''${1:-default}"
 
-          local COMPILED=$HOME/.config/s6/compiled
-          local LIVE=$HOME/.config/s6/live
-          local SCANDIR=$HOME/.config/s6/scandir
+          local COMPILED="$HOME/.config/s6/compiled"
+          local LIVE="$HOME/.config/s6/live"
+          local SCANDIR="$HOME/.config/s6/scandir"
 
-          rm -rf $SCANDIR
-          mkdir $SCANDIR
-          s6-svscan $SCANDIR &
+          rm -rf "$SCANDIR"
+          mkdir "$SCANDIR"
+          s6-svscan "$SCANDIR" &
           local SVSCAN=$!
 
           # the scandir is just links back into the compiled dir,
           # so the compiled dir therefore needs to be writable:
-          rm -rf $COMPILED
-          cp --dereference -R $COMPILED-static $COMPILED
-          chmod -R 0700 $COMPILED
+          rm -rf "$COMPILED"
+          cp --dereference -R "$COMPILED-static" "$COMPILED"
+          chmod -R 0700 "$COMPILED"
 
-          s6-rc-init -c $COMPILED -l $LIVE -d $SCANDIR
-
-          # echo default: deps
-          # s6-rc-db -c $COMPILED contents default
-          # echo graphical-session: deps
-          # s6-rc-db -c $COMPILED contents graphical-session
+          s6-rc-init -c "$COMPILED" -l "$LIVE" -d "$SCANDIR"
 
           if [ -n "$S6_TARGET" ]; then
-            s6-rc -l $LIVE start "$S6_TARGET"
+            s6-rc -l "$LIVE" start "$S6_TARGET"
           fi
 
-          echo "s6 initialized: Ctrl+C to stop"
-          wait $SVSCAN
+          echo 's6 initialized: Ctrl+C to stop'
+          wait "$SVSCAN"
+        }
+        function startS6WithLogging() {
+          # TODO: might not want to create log dir here: move to nix fs/persistence.
+          mkdir -p "${logBase}"
+          startS6 2>&1 | tee /dev/stderr | s6-log -- T "${logBase}"
         }
 
-        primarySessionCommands+=('startS6 &')
+        primarySessionCommands+=('startS6WithLogging &')
       '';
     }));
   };