feat: add EMQX_LOG_DIR env

rel/emqx_vars

@@ -9,9 +9,9 @@ ERL_OPTS="{{ erl_opts }}"
 RUNNER_BIN_DIR="{{ runner_bin_dir }}"
 RUNNER_LIB_DIR="{{ runner_lib_dir }}"
 IS_ELIXIR="${IS_ELIXIR:-{{ is_elixir }}}"
-## Allow users to pre-set `RUNNER_LOG_DIR` because it only affects boot commands like `start` and `console`,
+## Allow users to pre-set `EMQX_LOG_DIR` because it only affects boot commands like `start` and `console`,
 ## but not other commands such as `ping` and `ctl`.
-RUNNER_LOG_DIR="${RUNNER_LOG_DIR:-{{ runner_log_dir }}}"
+RUNNER_LOG_DIR="${EMQX_LOG_DIR:-${RUNNER_LOG_DIR:-{{ runner_log_dir }}}}"
 EMQX_ETC_DIR="{{ emqx_etc_dir }}"
 RUNNER_USER="{{ runner_user }}"
 SCHEMA_MOD="{{ emqx_schema_mod }}"