From 2c890482a7b01514befde78b155cd3d3d9d58fa5 Mon Sep 17 00:00:00 2001
From: Badlop <badlop@process-one.net>
Date: Tue, 20 Aug 2024 13:19:14 +0200
Subject: [PATCH] Apply uid changes

---
 ecs/bin/ejabberdctl | 37 ++++++++++++++++++++++++++++---------
 1 file changed, 28 insertions(+), 9 deletions(-)

diff --git a/ecs/bin/ejabberdctl b/ecs/bin/ejabberdctl
index 4dd128e..a9ef6c0 100644
--- a/ecs/bin/ejabberdctl
+++ b/ecs/bin/ejabberdctl
@@ -258,15 +258,34 @@ help()
 }
 
 # dynamic node name helper
-uid()
-{
-    uuid=$(uuidgen 2>/dev/null)
-    [ -z "$uuid" ] && [ -f /proc/sys/kernel/random/uuid ] && uuid=$(cat /proc/sys/kernel/random/uuid)
-    [ -z "$uuid" ] && uuid=$(printf "%X" "${RANDOM:-$$}$(date +%M%S)")
-    uuid=$(printf '%s' $uuid | sed 's/^\(...\).*$/\1/')
-    [ $# -eq 0 ] && echo "${uuid}-${ERLANG_NODE}"
-    [ $# -eq 1 ] && echo "${uuid}-${1}-${ERLANG_NODE}"
-    [ $# -eq 2 ] && echo "${uuid}-${1}@${2}"
+uid() {
+  ERTSVERSION="$("$ERL" -version 2>&1 | sed 's|.*\([0-9][0-9]\).*|\1|g')"
+  if [ $ERTSVERSION -lt 11 ] ; then # otp 23.0 includes erts 11.0
+    # Erlang/OTP lower than 23, which doesn's support dynamic node code
+    N=1
+    PF=$(( $$ % 97 ))
+    while
+      case $# in
+        0) NN="${PF}-${N}-${ERLANG_NODE}"
+          ;;
+        1) NN="${PF}-${N}-${1}-${ERLANG_NODE}"
+          ;;
+        2) NN="${PF}-${N}-${1}@${2}"
+          ;;
+      esac
+      N=$(( N + 1 + ( $$ % 5 ) ))
+      "$EPMD" -names 2>/dev/null | grep -q " ${NN%@*} "
+    do :; done
+    echo $NN
+  else
+    # Erlang/OTP 23 or higher: use native dynamic node code
+    # https://www.erlang.org/patches/otp-23.0#OTP-13812
+    if [ "$ERLANG_NODE" != "${ERLANG_NODE%.*}" ]; then
+      echo "undefined@${ERLANG_NODE#*@}"
+    else
+      echo "undefined"
+    fi
+  fi
 }
 
 # stop epmd if there is no other running node