jitsi-videobridge: add passthru.updateScript

Add a script to auto-update to the most recent stable version of
jitsi-videobridge.

pkgs/servers/jitsi-videobridge/default.nix

@@ -38,6 +38,8 @@ stdenv.mkDerivation {
     single-host-smoke-test = nixosTests.jitsi-meet;
   };
 
+  passthru.updateScript = ./update.sh;
+
   meta = with lib; {
     description = "A WebRTC compatible video router";
     longDescription = ''

pkgs/servers/jitsi-videobridge/update.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env nix-shell
+#!nix-shell -i bash -p curl pup common-updater-scripts
+
+set -eu -o pipefail
+
+version="$(curl https://download.jitsi.org/stable/ | \
+    pup 'a[href] text{}' | \
+    awk -F'[_-]' '/jitsi-videobridge2/ {printf $3"-"$4"-"$5"\n"}' | \
+    sort -u | \
+    tail -n 1)"
+
+update-source-version jitsi-videobridge "$version"