From 36137dd0e9882090b3b03300f79fa5b0f652a76a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Holger=20Wei=C3=9F?= <holger@zedat.fu-berlin.de>
Date: Mon, 8 Nov 2021 22:05:33 +0100
Subject: [PATCH] extended_bin: Support 'inet_dist_use_interface'

Support specifying the kernel option 'inet_dist_use_interface' in the
vm.args file. If ERL_DIST_PORT is set while using Erlang/OTP 23+, make
sure to hand over the 'inet_dist_use_interface' address to erl_call.
---
 priv/templates/extended_bin | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/priv/templates/extended_bin b/priv/templates/extended_bin
index f02f21872..38ce69faa 100644
--- a/priv/templates/extended_bin
+++ b/priv/templates/extended_bin
@@ -328,8 +328,8 @@ erl_rpc() {
                 DYNAMIC_NAME="-r"
             fi
 
-            if [ "$ERL_DIST_PORT" ]; then
-                result=$("$ERL_RPC" "${DYNAMIC_NAME}" -c "${COOKIE}" -address "${ERL_DIST_PORT}" -timeout "${RELX_RPC_TIMEOUT}" -a "${command}")
+            if [ "$ADDRESS" ]; then
+                result=$("$ERL_RPC" "${DYNAMIC_NAME}" -c "${COOKIE}" -address "${ADDRESS}" -timeout "${RELX_RPC_TIMEOUT}" -a "${command}")
             else
                 result=$("$ERL_RPC" "$NAME_TYPE" "$NAME" "${DYNAMIC_NAME}" -c "${COOKIE}" -timeout "${RELX_RPC_TIMEOUT}" -a "${command}")
             fi
@@ -352,7 +352,7 @@ erl_eval() {
             command=$*
 
             if [ "$ERL_DIST_PORT" ]; then
-                result=$(echo "${command}" | "$ERL_RPC" "${DYNAMIC_NAME}" -c "${COOKIE}" -address "${ERL_DIST_PORT}" -timeout "${RELX_RPC_TIMEOUT}" -e)
+                result=$(echo "${command}" | "$ERL_RPC" "${DYNAMIC_NAME}" -c "${COOKIE}" -address "${ADDRESS}" -timeout "${RELX_RPC_TIMEOUT}" -e)
             else
                 result=$(echo "${command}" | "$ERL_RPC" "$NAME_TYPE" "$NAME" "${DYNAMIC_NAME}" -c "${COOKIE}" -timeout "${RELX_RPC_TIMEOUT}" -e)
             fi
@@ -410,6 +410,22 @@ relx_escript() {
     "$ERTS_DIR/bin/escript" "$ROOTDIR/$scriptpath" "$@"
 }
 
+# Convert {127,0,0,1} to 127.0.0.1 (inet:ntoa/1)
+addr_tuple_to_str() {
+    addr="$1"
+    saved_IFS="$IFS"
+    IFS="{,}'\" "
+    # shellcheck disable=SC2086
+    eval set -- $addr
+    IFS="$saved_IFS"
+
+    case $# in
+    4) printf '%u.%u.%u.%u' "$@";;
+    8) printf '%.4x:%.4x:%.4x:%.4x:%.4x:%.4x:%.4x:%.4x' "$@";;
+    *) echo "Cannot parse IP address tuple: '$addr'" 1>&2;;
+    esac
+}
+
 make_out_file_path() {
     # Use output directory provided in the RELX_OUT_FILE_PATH environment variable
     # (default to the current location of vm.args and sys.config)
@@ -674,8 +690,17 @@ EPMD_MODULE="$(grep '^-epmd_module' "$VMARGS_PATH" || true)"
 if [ "$EPMD_MODULE" ]; then
     DIST_ARGS="${DIST_ARGS} ${EPMD_MODULE}"
 fi
+INET_DIST_USE_INTERFACE="$(grep '^-kernel  *inet_dist_use_interface' "$VMARGS_PATH" || true)"
+if [ "$INET_DIST_USE_INTERFACE" ]; then
+    DIST_ARGS="${DIST_ARGS} ${INET_DIST_USE_INTERFACE}"
+fi
 
 if [ "$ERL_DIST_PORT" ]; then
+    if [ "$INET_DIST_USE_INTERFACE" ]; then
+        ADDRESS="$(addr_tuple_to_str "${INET_DIST_USE_INTERFACE#*inet_dist_use_interface }"):$ERL_DIST_PORT"
+    else
+        ADDRESS="$ERL_DIST_PORT"
+    fi
     if [  "11.1" = "$(printf "%s\n11.1" "${ERTS_VSN}" | sort -V | head -n1)" ] ; then
         # unless set by the user, set start_epmd to false when ERL_DIST_PORT is used
         if [ ! "$START_EPMD" ]; then