From 2b14dd6a9b02aa2be46276517404f9ee3818eb87 Mon Sep 17 00:00:00 2001
From: Jocelyn Le Sage <jocelyn@le-sage.com>
Date: Mon, 10 Oct 2022 13:49:35 -0400
Subject: [PATCH] Fixed handling of supplementary groups for sound device.

---
 rootfs/etc/cont-init.d/55-check-snd.sh |  4 ----
 rootfs/etc/services.d/app/sgid         | 28 ++++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)
 create mode 100755 rootfs/etc/services.d/app/sgid

diff --git a/rootfs/etc/cont-init.d/55-check-snd.sh b/rootfs/etc/cont-init.d/55-check-snd.sh
index 1e917f3..58b805c 100755
--- a/rootfs/etc/cont-init.d/55-check-snd.sh
+++ b/rootfs/etc/cont-init.d/55-check-snd.sh
@@ -13,9 +13,5 @@ fi
 # Save the associated group.
 SND_GRP="$(find "$SND_DEV" -maxdepth 1 -not -type d -exec stat -c "%g" {} \; | sort -u | tail -n1)"
 echo "sound device group $SND_GRP."
-if [ -f /var/run/s6/container_environment/SUP_GROUP_IDS ]; then
-    echo -n "," >> /var/run/s6/container_environment/SUP_GROUP_IDS
-fi
-echo -n "$SND_GRP" >> /var/run/s6/container_environment/SUP_GROUP_IDS
 
 # vim: set ft=sh :
diff --git a/rootfs/etc/services.d/app/sgid b/rootfs/etc/services.d/app/sgid
new file mode 100755
index 0000000..48f972d
--- /dev/null
+++ b/rootfs/etc/services.d/app/sgid
@@ -0,0 +1,28 @@
+#!/bin/sh
+#
+# Get the supplementary group ID(s) needed to access sound device.  These are
+# added to the ones provided by $SUP_GROUP_IDS.
+#
+
+set -e # Exit immediately if a command exits with a non-zero status.
+set -u # Treat unset variables as an error.
+
+SND_DEV="/dev/snd"
+
+SUP_GROUP_IDS="${SUP_GROUP_IDS:-}"
+
+# Add group associated to the sound device.
+if [ -d "$SND_DEV" ]; then
+    # Save the associated group.
+    SND_GRP="$(find "$SND_DEV" -maxdepth 1 -not -type d -exec stat -c "%g" {} \; | sort -u | tail -n1)"
+
+    if [ -n "$SUP_GROUP_IDS" ]; then
+        SUP_GROUP_IDS="$SUP_GROUP_IDS,$SND_GRP"
+    else
+        SUP_GROUP_IDS="$SND_GRP"
+    fi
+fi
+
+echo "$SUP_GROUP_IDS" | tr ',' '\n'
+
+# vim:ft=sh:ts=4:sw=4:et:sts=4