feat(resty.kong.log): add more return value for `resty.kong.log.get_l…

…og_level()` (#88)

KAG-4258

---------

Co-authored-by: Datong Sun <datong.sun@konghq.com>

README.md

@@ -463,14 +463,16 @@ If we don’t pass timeout to set_log_level(), it will raise a Lua error.
 
 resty.kong.log.get\_log\_level
 ----------------------------------
-**syntax:** *resty.kong.log.get_log_level(level)*
+**syntax:** *current_level, timeout, original_level = resty.kong.log.get_log_level()*
 
 **context:** *any*
 
 **subsystems:** *http*
 
-If the dynamic log level is set, it will return the dynamic log level,
-otherwise it will return `level`.
+Returns the current dynamic log level, remaining timeout and the original log level.
+
+If the dynamic log level is not set or not active,
+`timeout` will be `0`.
 
 Please see [Nginx log level constants](https://github.com/openresty/lua-nginx-module#nginx-log-level-constants)
 for the possible value of `level`.

lualib/resty/kong/log.lua

@@ -26,7 +26,8 @@ int
 ngx_http_lua_kong_ffi_set_dynamic_log_level(int log_level, int timeout);
 
 int
-ngx_http_lua_kong_ffi_get_dynamic_log_level(int current_log_level);
+ngx_http_lua_kong_ffi_get_dynamic_log_level(ngx_http_request_t *r,
+    int *current_log_level, int *timeout, int *original_log_level);
 ]])
 
 
@@ -57,11 +58,26 @@ function _M.set_log_level(level, timeout)
 end
 
 
-function _M.get_log_level(level)
-    assert(type(level) == "number", "level must be a number")
-    assert(math_floor(level) == level, "level must be an integer")
+do
+    local tonumber = tonumber
+    local get_request = base.get_request
+
+    local current_log_level = ffi.new("int[1]")
+    local original_log_level = ffi.new("int[1]")
+    local timeout = ffi.new("int[1]")
 
-    return tonumber(C.ngx_http_lua_kong_ffi_get_dynamic_log_level(level))
+    function _M.get_log_level()
+        local rc = C.ngx_http_lua_kong_ffi_get_dynamic_log_level(get_request(),
+                                                                 current_log_level,
+                                                                 timeout,
+                                                                 original_log_level)
+        if rc ~= NGX_OK then
+            error("failed to get dynamic log level: " .. tostring(rc))
+        end
+
+        return tonumber(current_log_level[0]), tonumber(timeout[0]),
+               tonumber(original_log_level[0])
+    end
 end
 
 

src/ngx_http_lua_kong_log.c

@@ -25,7 +25,7 @@
 **
 ** Excluding the technical view,
 ** the Kong Gateway does not supoort the Windows OS.
-** 
+**
 */
 #error "The dynamic log level feature is only supported on UNIX like system"
 #endif
@@ -36,7 +36,7 @@
 static ngx_uint_t g_dynamic_log_level = NGX_CONF_UNSET_UINT;
 
 /* after this time, the dynamic log level will restore to original value */
-static time_t     g_dynamic_log_level_timeout_at; 
+static time_t     g_dynamic_log_level_timeout_at;
 
 /* ------------------------------------------------------------------------- */
 
@@ -64,28 +64,62 @@ ngx_http_lua_kong_ffi_set_dynamic_log_level(int log_level, int timeout)
     }
 
     g_dynamic_log_level = log_level;
-    g_dynamic_log_level_timeout_at = (time_t)ngx_time() + (time_t)timeout;
+    g_dynamic_log_level_timeout_at = (time_t) ngx_time() + (time_t) timeout;
 
     return NGX_OK;
 }
 
+
 ngx_uint_t
 ngx_http_lua_kong_get_dynamic_log_level(ngx_uint_t current_log_level)
 {
     if (g_dynamic_log_level == NGX_CONF_UNSET_UINT) {
         return current_log_level;
     }
 
-    if (g_dynamic_log_level_timeout_at < ngx_time()) {
+    if (g_dynamic_log_level_timeout_at <= ngx_time()) {
         g_dynamic_log_level = NGX_CONF_UNSET_UINT;
         return current_log_level;
     }
 
     return g_dynamic_log_level;
 }
 
+
 int
-ngx_http_lua_kong_ffi_get_dynamic_log_level(int current_log_level)
+ngx_http_lua_kong_ffi_get_dynamic_log_level(ngx_http_request_t *r,
+    int *current_log_level, int *timeout, int *original_log_level)
 {
-    return ngx_http_lua_kong_get_dynamic_log_level(current_log_level);
+    if (current_log_level == NULL || timeout == NULL || original_log_level == NULL) {
+        return NGX_ERROR;
+    }
+
+    *original_log_level = r == NULL ?
+                          ngx_cycle->log->log_level:
+                          r->connection->log->log_level;
+
+    /* nginx's log_level may be 0x7ffffff0, 0x80000000
+     * see src/core/ngx_log.h
+     */
+    if (*original_log_level > NGX_LOG_DEBUG) {
+        *original_log_level = NGX_LOG_DEBUG;
+    }
+
+    /* timeout, disable the dynamic log level */
+    if (g_dynamic_log_level_timeout_at <= ngx_time()) {
+        g_dynamic_log_level = NGX_CONF_UNSET_UINT;
+    }
+
+    if (g_dynamic_log_level == NGX_CONF_UNSET_UINT) {
+        *current_log_level = *original_log_level;
+        *timeout = 0;
+
+    } else {
+        *current_log_level = g_dynamic_log_level;
+        *timeout = g_dynamic_log_level_timeout_at - (time_t) ngx_time();
+    }
+
+    ngx_http_lua_kong_assert(*timeout >= 0);
+
+    return NGX_OK;
 }