add a notify.d script to post messages to a Matrix room

Makefile

@@ -11,6 +11,8 @@ install: all
 	cp hooks/* "$(DESTDIR)/etc/needrestart/hook.d/"
 	cp ex/needrestart.conf "$(DESTDIR)/etc/needrestart/"
 	cp ex/notify.conf "$(DESTDIR)/etc/needrestart/"
+	cp ex/matrix.conf "$(DESTDIR)/etc/needrestart/"
+	chmod 0600 "$(DESTDIR)/etc/needrestart/matrix.conf"
 	cp ex/iucode.sh "$(DESTDIR)/etc/needrestart/"
 	mkdir -p "$(DESTDIR)/etc/needrestart/conf.d"
 	cp ex/conf.d/* "$(DESTDIR)/etc/needrestart/conf.d/"

ex/matrix.conf

@@ -0,0 +1,11 @@
+
+export MATRIX_SERVER="https://matrix.org/"
+
+# The room ID where the message should be posted (not the room alias).
+# https://matrix.org/docs/older/client-server-api/#creating-a-room
+export MATRIX_ROOM_ID=""
+
+# Authentication Token from the account that posts the messages.
+# https://matrix.org/docs/older/client-server-api/#registration
+# Therefore, this file should be kept secret! chmod 0600 matrix.conf
+export MATRIX_TOKEN=""

ex/notify.conf

@@ -15,6 +15,9 @@
 # Disable mail to user (notify.d/600-mail)
 NR_NOTIFYD_DISABLE_MAIL='1'
 
+# Disable matrix messages (notify.d/800-matrix)
+NR_NOTIFYD_DISABLE_MATRIX='1'
+
 
 # Where to find the shell function library from gettext-base
 #GETTEXTLIB='/usr/bin/gettext.sh'

ex/notify.d/800-matrix

@@ -0,0 +1,62 @@
+#!/bin/sh
+
+# needrestart - Restart daemons after library updates.
+#
+# Authors:
+#   Hans-Christoph Steiner <hans@eds.org>
+#
+# Copyright Holder:
+#   2026 (C) Hans-Christoph Steiner <hans@eds.org>
+#
+# License:
+#   This program is free software; you can redistribute it and/or modify
+#   it under the terms of the GNU General Public License as published by
+#   the Free Software Foundation; either version 2 of the License, or
+#   (at your option) any later version.
+#
+
+# Use /usr/bin/curl to post a message to a Matrix room
+
+CURL=/usr/bin/curl
+test -x "$CURL" || exit 1
+
+. /usr/lib/needrestart/notify.d.sh
+
+if [ "$NR_NOTIFYD_DISABLE_MATRIX" = '1' ]; then
+    echo "[$0] disabled in global config" 1>&2
+    exit 1
+fi
+
+MATRIXCONF="$(dirname "$NOTIFYCONF")/matrix.conf"
+
+perms=$(stat --format=%a "$MATRIXCONF")
+if [ "$perms" -ne "600" ]; then
+    echo "[$0] $MATRIXCONF has unsafe permissions $perms - aborting!" 1>&2
+    exit 1;
+fi
+
+if [ ! -r "$MATRIXCONF" ]; then
+    echo "[$0] Unable to read $MATRIXCONF - aborting!" 1>&2
+    exit 1;
+fi
+
+. "$MATRIXCONF"
+
+echo "[$0] notify Matrix room $MATRIX_ROOM_ID on $MATRIX_SERVER" 1>&2
+
+body=$({
+    _NR_FQDN=$(hostname -f)
+    eval_gettext 'Your session on host $_NR_FQDN ($NR_SESSION) is running obsolete binaries or libraries as listed below.'
+    echo
+    echo
+    gettext "Please consider a relogin or restart of the affected processes!"
+    echo
+    echo
+    cat
+})
+
+$CURL \
+    --header "Authorization: Bearer $MATRIX_TOKEN" \
+    --header "Content-Type: application/json" \
+    --json "{\"msgtype\": \"m.text\", \"body\": \"$(echo $body)\"}" \
+    "${MATRIX_SERVER}_matrix/client/r0/rooms/${MATRIX_ROOM_ID}/send/m.room.message"