From ba43da1b8e6b3e00ebde5b63f32c593a6c33d4f0 Mon Sep 17 00:00:00 2001
From: ieQu1 <99872536+ieQu1@users.noreply.github.com>
Date: Tue, 26 Mar 2024 13:32:14 +0100
Subject: [PATCH] fix(mria): Strictly check compatibility of the replicant with
 core

---
 apps/emqx/rebar.config                 |  2 +-
 apps/emqx_machine/src/emqx_machine.erl | 26 ++++++++++++++++++++++++++
 changes/ce/fix-12786.en.md             |  2 ++
 mix.exs                                |  2 +-
 rebar.config                           |  2 +-
 5 files changed, 31 insertions(+), 3 deletions(-)
 create mode 100644 changes/ce/fix-12786.en.md

diff --git a/apps/emqx/rebar.config b/apps/emqx/rebar.config
index 3822078b7..60ac6343f 100644
--- a/apps/emqx/rebar.config
+++ b/apps/emqx/rebar.config
@@ -28,7 +28,7 @@
     {gproc, {git, "https://github.com/emqx/gproc", {tag, "0.9.0.1"}}},
     {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.9.2"}}},
     {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.11.1"}}},
-    {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.19.0"}}},
+    {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.19.1"}}},
     {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "3.3.1"}}},
     {hocon, {git, "https://github.com/emqx/hocon.git", {tag, "0.42.1"}}},
     {emqx_http_lib, {git, "https://github.com/emqx/emqx_http_lib.git", {tag, "0.5.3"}}},
diff --git a/apps/emqx_machine/src/emqx_machine.erl b/apps/emqx_machine/src/emqx_machine.erl
index d8858ff16..14f871e8a 100644
--- a/apps/emqx_machine/src/emqx_machine.erl
+++ b/apps/emqx_machine/src/emqx_machine.erl
@@ -27,6 +27,7 @@
 ]).
 
 -export([open_ports_check/0]).
+-export([mria_lb_custom_info/0, mria_lb_custom_info_check/1]).
 
 -ifdef(TEST).
 -export([create_plan/0]).
@@ -51,6 +52,13 @@ start() ->
     configure_shard_transports(),
     set_mnesia_extra_diagnostic_checks(),
     emqx_otel_app:configure_otel_deps(),
+    %% Register mria callbacks that help to check compatibility of the
+    %% replicant with the core node. Currently they rely on the exact
+    %% match of the version of EMQX OTP application:
+    _ = application:load(mria),
+    _ = application:load(emqx),
+    mria_config:register_callback(lb_custom_info, fun ?MODULE:mria_lb_custom_info/0),
+    mria_config:register_callback(lb_custom_info_check, fun ?MODULE:mria_lb_custom_info_check/1),
     ekka:start(),
     ok.
 
@@ -227,3 +235,21 @@ resolve_dist_address_type() ->
         _ ->
             inet
     end.
+
+%% Note: this function is stored in the Mria's application environment
+mria_lb_custom_info() ->
+    get_emqx_vsn().
+
+%% Note: this function is stored in the Mria's application environment
+mria_lb_custom_info_check(undefined) ->
+    false;
+mria_lb_custom_info_check(OtherVsn) ->
+    get_emqx_vsn() =:= OtherVsn.
+
+get_emqx_vsn() ->
+    case application:get_key(emqx, vsn) of
+        {ok, Vsn} ->
+            Vsn;
+        undefined ->
+            undefined
+    end.
diff --git a/changes/ce/fix-12786.en.md b/changes/ce/fix-12786.en.md
new file mode 100644
index 000000000..49acef7da
--- /dev/null
+++ b/changes/ce/fix-12786.en.md
@@ -0,0 +1,2 @@
+Add a strict check that prevents replicant nodes from connecting to the core nodes running with a different version of EMQX application.
+Effectively it means that during the rolling upgrades the replicant nodes can only work if there is at least one core node with the matching EMQX release.
diff --git a/mix.exs b/mix.exs
index 74dbfad5c..09f5f0692 100644
--- a/mix.exs
+++ b/mix.exs
@@ -55,7 +55,7 @@ defmodule EMQXUmbrella.MixProject do
       {:cowboy, github: "emqx/cowboy", tag: "2.9.2", override: true},
       {:esockd, github: "emqx/esockd", tag: "5.11.1", override: true},
       {:rocksdb, github: "emqx/erlang-rocksdb", tag: "1.8.0-emqx-2", override: true},
-      {:ekka, github: "emqx/ekka", tag: "0.19.0", override: true},
+      {:ekka, github: "emqx/ekka", tag: "0.19.1", override: true},
       {:gen_rpc, github: "emqx/gen_rpc", tag: "3.3.1", override: true},
       {:grpc, github: "emqx/grpc-erl", tag: "0.6.12", override: true},
       {:minirest, github: "emqx/minirest", tag: "1.4.0", override: true},
diff --git a/rebar.config b/rebar.config
index 6713b5c9b..238dca515 100644
--- a/rebar.config
+++ b/rebar.config
@@ -83,7 +83,7 @@
     {cowboy, {git, "https://github.com/emqx/cowboy", {tag, "2.9.2"}}},
     {esockd, {git, "https://github.com/emqx/esockd", {tag, "5.11.1"}}},
     {rocksdb, {git, "https://github.com/emqx/erlang-rocksdb", {tag, "1.8.0-emqx-2"}}},
-    {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.19.0"}}},
+    {ekka, {git, "https://github.com/emqx/ekka", {tag, "0.19.1"}}},
     {gen_rpc, {git, "https://github.com/emqx/gen_rpc", {tag, "3.3.1"}}},
     {grpc, {git, "https://github.com/emqx/grpc-erl", {tag, "0.6.12"}}},
     {minirest, {git, "https://github.com/emqx/minirest", {tag, "1.4.0"}}},