From 25d6a98aa4b361a35f6c2096bcae59b55240ba92 Mon Sep 17 00:00:00 2001
From: Zaiming Shi <zmstone@gmail.com>
Date: Tue, 16 Nov 2021 09:44:38 +0100
Subject: [PATCH] build: get otp version and export OTP_VSN

---
 Makefile               | 1 +
 scripts/get-otp-vsn.sh | 5 +++++
 2 files changed, 6 insertions(+)
 create mode 100755 scripts/get-otp-vsn.sh

diff --git a/Makefile b/Makefile
index ad5344c39..938ccf736 100644
--- a/Makefile
+++ b/Makefile
@@ -3,6 +3,7 @@ REBAR_VERSION = 3.16.1-emqx-1
 REBAR = $(CURDIR)/rebar3
 BUILD = $(CURDIR)/build
 SCRIPTS = $(CURDIR)/scripts
+export OTP_VSN ?= $(shell $(CURDIR)/scripts/get-otp-vsn.sh)
 export PKG_VSN ?= $(shell $(CURDIR)/pkg-vsn.sh)
 export EMQX_DESC ?= EMQ X
 export EMQX_DASHBOARD_VERSION ?= v5.0.0-beta.18
diff --git a/scripts/get-otp-vsn.sh b/scripts/get-otp-vsn.sh
new file mode 100755
index 000000000..a791318dc
--- /dev/null
+++ b/scripts/get-otp-vsn.sh
@@ -0,0 +1,5 @@
+#!/bin/bash
+
+set -euo pipefail
+
+erl  -noshell -eval '{ok, Version} = file:read_file(filename:join([code:root_dir(), "releases", erlang:system_info(otp_release), "OTP_VERSION"])), io:fwrite(Version), halt().'