MINOR: lua: post initialisation bindings
This system permits to execute some lua function after than HAProxy
complete his initialisation. These functions are executed between
the end of the configuration parsing and check and the begin of the
scheduler.
diff --git a/src/haproxy.c b/src/haproxy.c
index 7656167..c3d6255 100644
--- a/src/haproxy.c
+++ b/src/haproxy.c
@@ -1058,6 +1058,10 @@
if (!global.node)
global.node = strdup(hostname);
+#ifdef USE_LUA
+ if (!hlua_post_init())
+ exit(1);
+#endif
}
static void deinit_acl_cond(struct acl_cond *cond)
diff --git a/src/hlua.c b/src/hlua.c
index 00b88ca..666aaf2 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -30,6 +30,9 @@
*/
struct pool_head *pool2_hlua_com;
+/* List head of the function called at the initialisation time. */
+struct list hlua_init_functions = LIST_HEAD_INIT(hlua_init_functions);
+
/* Store the fast lua context for coroutines. This tree uses the
* Lua stack pointer value as indexed entry, and store the associated
* hlua context.
@@ -435,6 +438,30 @@
return ret;
}
+/* This function is an LUA binding that register LUA function to be
+ * executed after the HAProxy configuration parsing and before the
+ * HAProxy scheduler starts. This function expect only one LUA
+ * argument that is a function. This function returns nothing, but
+ * throws if an error is encountered.
+ */
+__LJMP static int hlua_register_init(lua_State *L)
+{
+ struct hlua_init_function *init;
+ int ref;
+
+ MAY_LJMP(check_args(L, 1, "register_init"));
+
+ ref = MAY_LJMP(hlua_checkfunction(L, 1));
+
+ init = malloc(sizeof(*init));
+ if (!init)
+ WILL_LJMP(luaL_error(L, "lua out of memory error."));
+
+ init->function_ref = ref;
+ LIST_ADDQ(&hlua_init_functions, &init->l);
+ return 0;
+}
+
/* This function is called by the main configuration key "lua-load". It loads and
* execute an lua file during the parsing of the HAProxy configuration file. It is
* the main lua entry point.
@@ -494,6 +521,35 @@
{ 0, NULL, NULL },
}};
+int hlua_post_init()
+{
+ struct hlua_init_function *init;
+ const char *msg;
+ enum hlua_exec ret;
+
+ list_for_each_entry(init, &hlua_init_functions, l) {
+ lua_rawgeti(gL.T, LUA_REGISTRYINDEX, init->function_ref);
+ ret = hlua_ctx_resume(&gL, 0);
+ switch (ret) {
+ case HLUA_E_OK:
+ lua_pop(gL.T, -1);
+ return 1;
+ case HLUA_E_AGAIN:
+ Alert("lua init: yield not allowed.\n");
+ return 0;
+ case HLUA_E_ERRMSG:
+ msg = lua_tostring(gL.T, -1);
+ Alert("lua init: %s.\n", msg);
+ return 0;
+ case HLUA_E_ERR:
+ default:
+ Alert("lua init: unknown runtime error.\n");
+ return 0;
+ }
+ }
+ return 1;
+}
+
void hlua_init(void)
{
int i;
@@ -536,6 +592,9 @@
for (i=0; i<NB_LOG_LEVELS; i++)
hlua_class_const_int(gL.T, log_levels[i], i);
+ /* Register special functions. */
+ hlua_class_function(gL.T, "register_init", hlua_register_init);
+
/* Store the table __index in the metable. */
lua_settable(gL.T, -3);