feat: support starting emqx from relup dir

We put all of the unpacked files into `relup` dir, and warn the user if boot from it

bin/emqx

@@ -13,53 +13,6 @@ if [ "$DEBUG" -eq 2 ]; then
   export PS4='+(${BASH_SOURCE}:${LINENO}): ${FUNCNAME[0]:+${FUNCNAME[0]}(): }'
 fi
 
-# We need to find real directory with emqx files on all platforms
-# even when bin/emqx is symlinked on several levels
-# - readlink -f works perfectly, but `-f` flag has completely different meaning in BSD version,
-#   so we can't use it universally.
-# - `stat -f%R` on MacOS does exactly what `readlink -f` does on Linux, but we can't use it
-#   as a universal solution either because GNU stat has different syntax and this argument is invalid.
-#   Also, version of stat which supports this syntax is only available since MacOS 12
-if [ "$(uname -s)" == 'Darwin' ]; then
-    product_version="$(sw_vers -productVersion | cut -d '.' -f 1)"
-    if [ "$product_version" -ge 12 ]; then
-        # if homebrew coreutils package is installed, GNU version of stat can take precedence,
-        # so we use absolute path to ensure we are calling MacOS default
-        RUNNER_ROOT_DIR="$(cd "$(dirname "$(/usr/bin/stat -f%R "$0" || echo "$0")")"/..; pwd -P)"
-    else
-        # try our best to resolve link on MacOS <= 11
-        RUNNER_ROOT_DIR="$(cd "$(dirname "$(readlink "$0" || echo "$0")")"/..; pwd -P)"
-    fi
-else
-    RUNNER_ROOT_DIR="$(cd "$(dirname "$(realpath "$0" || echo "$0")")"/..; pwd -P)"
-fi
-
-# shellcheck disable=SC1090,SC1091
-. "$RUNNER_ROOT_DIR"/releases/emqx_vars
-
-# defined in emqx_vars
-export RUNNER_ROOT_DIR
-export EMQX_ETC_DIR
-export REL_VSN
-export SCHEMA_MOD
-export IS_ENTERPRISE
-
-RUNNER_SCRIPT="$RUNNER_BIN_DIR/$REL_NAME"
-CODE_LOADING_MODE="${CODE_LOADING_MODE:-embedded}"
-REL_DIR="$RUNNER_ROOT_DIR/releases/$REL_VSN"
-
-WHOAMI=$(whoami 2>/dev/null || id -u)
-
-# hocon try to read environment variables starting with "EMQX_"
-export HOCON_ENV_OVERRIDE_PREFIX='EMQX_'
-
-export ERTS_DIR="$RUNNER_ROOT_DIR/erts-$ERTS_VSN"
-export BINDIR="$ERTS_DIR/bin"
-export EMU="beam"
-export PROGNAME="erl"
-export ERTS_LIB_DIR="$RUNNER_ROOT_DIR/lib"
-DYNLIBS_DIR="$RUNNER_ROOT_DIR/dynlibs"
-
 logerr() {
     if [ "${TERM:-dumb}" = dumb ]; then
         echo -e "ERROR: $*" 1>&2
@@ -89,6 +42,64 @@ die() {
     exit "$errno"
 }
 
+# We need to find real directory with emqx files on all platforms
+# even when bin/emqx is symlinked on several levels
+# - readlink -f works perfectly, but `-f` flag has completely different meaning in BSD version,
+#   so we can't use it universally.
+# - `stat -f%R` on MacOS does exactly what `readlink -f` does on Linux, but we can't use it
+#   as a universal solution either because GNU stat has different syntax and this argument is invalid.
+#   Also, version of stat which supports this syntax is only available since MacOS 12
+if [ "$(uname -s)" == 'Darwin' ]; then
+    product_version="$(sw_vers -productVersion | cut -d '.' -f 1)"
+    if [ "$product_version" -ge 12 ]; then
+        # if homebrew coreutils package is installed, GNU version of stat can take precedence,
+        # so we use absolute path to ensure we are calling MacOS default
+        RUNNER_ROOT_DIR="$(cd "$(dirname "$(/usr/bin/stat -f%R "$0" || echo "$0")")"/..; pwd -P)"
+    else
+        # try our best to resolve link on MacOS <= 11
+        RUNNER_ROOT_DIR="$(cd "$(dirname "$(readlink "$0" || echo "$0")")"/..; pwd -P)"
+    fi
+else
+    RUNNER_ROOT_DIR="$(cd "$(dirname "$(realpath "$0" || echo "$0")")"/..; pwd -P)"
+fi
+
+BASE_RUNNER_ROOT_DIR="${BASE_RUNNER_ROOT_DIR:-$RUNNER_ROOT_DIR}"
+
+if [ -f "$RUNNER_ROOT_DIR/relup/version" ]; then
+    TARGET_VSN=$(cat "$RUNNER_ROOT_DIR/relup/version")
+    export BASE_RUNNER_ROOT_DIR
+    logwarn "Loading emqx from hot upgrade dir: $RUNNER_ROOT_DIR/relup"
+    exec $RUNNER_ROOT_DIR/relup/$TARGET_VSN/bin/emqx "$@"
+else
+    logdebug "Loading emqx from $RUNNER_ROOT_DIR"
+fi
+
+# shellcheck disable=SC1090,SC1091
+. "$RUNNER_ROOT_DIR"/releases/emqx_vars
+
+# defined in emqx_vars
+export RUNNER_ROOT_DIR
+export EMQX_ETC_DIR
+export REL_VSN
+export SCHEMA_MOD
+export IS_ENTERPRISE
+
+RUNNER_SCRIPT="$RUNNER_BIN_DIR/$REL_NAME"
+CODE_LOADING_MODE="${CODE_LOADING_MODE:-embedded}"
+REL_DIR="$RUNNER_ROOT_DIR/releases/$REL_VSN"
+
+WHOAMI=$(whoami 2>/dev/null || id -u)
+
+# hocon try to read environment variables starting with "EMQX_"
+export HOCON_ENV_OVERRIDE_PREFIX='EMQX_'
+
+export ERTS_DIR="$RUNNER_ROOT_DIR/erts-$ERTS_VSN"
+export BINDIR="$ERTS_DIR/bin"
+export EMU="beam"
+export PROGNAME="erl"
+export ERTS_LIB_DIR="$RUNNER_ROOT_DIR/lib"
+DYNLIBS_DIR="$RUNNER_ROOT_DIR/dynlibs"
+
 assert_node_alive() {
     if ! relx_nodetool "ping" > /dev/null; then
         exit 1
@@ -598,7 +609,7 @@ DATA_DIR="$(get_boot_config 'node.data_dir')"
 DATA_DIR="${DATA_DIR%/}"
 if [[ $DATA_DIR != /* ]]; then
     # relative path
-    DATA_DIR="${RUNNER_ROOT_DIR}/${DATA_DIR}"
+    DATA_DIR="${BASE_RUNNER_ROOT_DIR}/${DATA_DIR}"
 fi
 CONFIGS_DIR="$DATA_DIR/configs"
 mkdir -p "$CONFIGS_DIR"
@@ -1060,7 +1071,7 @@ nodetool_shutdown() {
     logger -t "${REL_NAME}[${PID}]" "STOP: OK"
 }
 
-cd "$RUNNER_ROOT_DIR"
+cd "$BASE_RUNNER_ROOT_DIR"
 
 case "${COMMAND}" in
     start)

rebar.config.erl

@@ -392,9 +392,9 @@ overlay_vars_pkg(bin) ->
         {platform_etc_dir, "etc"},
         {platform_plugins_dir, "plugins"},
         {runner_bin_dir, "$RUNNER_ROOT_DIR/bin"},
-        {emqx_etc_dir, "$RUNNER_ROOT_DIR/etc"},
+        {emqx_etc_dir, "$BASE_RUNNER_ROOT_DIR/etc"},
         {runner_lib_dir, "$RUNNER_ROOT_DIR/lib"},
-        {runner_log_dir, "$RUNNER_ROOT_DIR/log"},
+        {runner_log_dir, "$BASE_RUNNER_ROOT_DIR/log"},
         {runner_user, ""},
         {is_elixir, "no"}
     ];

relup/examples/5.6.1-to-5.6.1+patch.A.relup

@@ -14,8 +14,7 @@
     target_version => "5.6.1+patch.A",
     from_version => "5.6.1",
     code_changes =>
-        [ {load_module, emqx_post_upgrade}
+        [ {load_module, emqx_broker}
-        , {load_module, emqx_broker}
         , {load_module, emqx_metrics}
         , {load_module, emqx_persistent_message}
         , {load_module, emqx_dashboard_monitor}