Fix: Remove redundant error logging for Lua filter execution

This commit removes redundant error logging that was previously performed during Lua filter script execution. By eliminating the `logError` function, errors are now managed more efficiently without unnecessary duplication in the logging process. Additionally, adjustments have been made to handle error returns directly, simplifying the error handling flow and enhancing readability.

Signed-off-by: Christian Roessner <[email protected]>

server/errors/errors.go

@@ -214,7 +214,6 @@ var (
 	ErrNoFiltersDefined         = errors.New("no filters defined")
 	ErrFilterLuaNameMissing     = errors.New("filter 'name' sttribute missing")
 	ErrFilterLuaScriptPathEmpty = errors.New("filter 'script_path' attribute missing")
-	ErrFilterFailed             = errors.New("filter failed")
 )
 
 // misc.

server/lua-plugins.d/filters/monitoring.lua

@@ -142,16 +142,37 @@ function nauthilus_call_filter(request)
     local session = get_dovecot_session()
 
     if session then
+        local result = {}
+
         local valid_servers = preprocess_backend_servers(nauthilus_backend.get_backend_servers())
         local num_of_bs = nauthilus_util.table_length(valid_servers)
 
+        if request.debug then
+            result.caller = N .. ".lua"
+            result.level = "debug"
+            result.ts = nauthilus_util.get_current_timestamp()
+            result.session = request.session
+            result.dovecot_session = session
+            result.protocol = request.protocol
+            result.account = request.account
+            result.backend_servers_alive = tostring(num_of_bs)
+
+            local backend_servers_hosts = {}
+            for _, server in ipairs(valid_servers) do
+                table.insert(backend_servers_hosts, server.host)
+            end
+
+            result.backend_servers = table.concat(backend_servers_hosts, ", ")
+        end
+
         if num_of_bs > 0 then
             local maybe_server = get_server_from_sessions(session)
 
             if maybe_server then
                 for _, server in ipairs(valid_servers) do
                     if server.host == maybe_server then
                         server_host = maybe_server
+                        result.backend_server_selected = server_host
 
                         break
                     end
@@ -161,9 +182,11 @@ function nauthilus_call_filter(request)
                     invalidate_stale_sessions()
 
                     server_host = valid_servers[math.random(1, num_of_bs)].host
+                    result.backend_server_selected = server_host
                 end
             else
                 server_host = valid_servers[math.random(1, num_of_bs)].host
+                result.backend_server_selected = server_host
             end
         end
 
@@ -178,6 +201,7 @@ function nauthilus_call_filter(request)
             -- Another client might have been faster at the same point in time...
             if expected_server and  server_host ~= expected_server then
                 server_host = expected_server
+                result.backend_server_selected = server_host
             end
 
             attributes["Proxy-Host"] = server_host
@@ -188,11 +212,10 @@ function nauthilus_call_filter(request)
             nauthilus_backend.apply_backend_result(backend_result)
         end
 
-        if server_host == nil then
-            nauthilus_builtin.custom_log_add(N .. "_backend_server", "failed")
-            nauthilus_builtin.status_message_set("No backend servers are available")
+        nauthilus_util.print_result({ log_format = request.log_format }, result, nil)
 
-            return nauthilus_builtin.FILTER_ACCEPT, nauthilus_builtin.FILTER_RESULT_FAIL
+        if server_host == nil then
+            error("No backend servers are available")
         end
     end
 

server/lualib/filter/filter.go

@@ -18,7 +18,6 @@ package filter
 import (
 	"context"
 	stderrors "errors"
-	"fmt"
 	"net/http"
 	"sync"
 	"time"
@@ -27,13 +26,11 @@ import (
 	"github.com/croessner/nauthilus/server/config"
 	"github.com/croessner/nauthilus/server/definitions"
 	"github.com/croessner/nauthilus/server/errors"
-	"github.com/croessner/nauthilus/server/log"
 	"github.com/croessner/nauthilus/server/lualib"
 	"github.com/croessner/nauthilus/server/monitoring"
 	"github.com/croessner/nauthilus/server/stats"
 	"github.com/croessner/nauthilus/server/util"
 	"github.com/gin-gonic/gin"
-	"github.com/go-kit/log/level"
 	"github.com/spf13/viper"
 	"github.com/yuin/gopher-lua"
 )
@@ -462,22 +459,16 @@ func executeScriptWithinContext(request *lua.LTable, script *LuaFilter, r *Reque
 
 	packagePathErr := lualib.PackagePath(L)
 	if packagePathErr != nil {
-		logError(r, script, packagePathErr)
-
 		return false, packagePathErr
 	}
 
 	scriptErr := lualib.DoCompiledFile(L, script.CompiledScript)
 	if scriptErr != nil {
-		logError(r, script, scriptErr)
-
 		return false, scriptErr
 	}
 
 	callErr := L.CallByParam(lua.P{Fn: L.GetGlobal(definitions.LuaFnCallFilter), NRet: 2, Protect: true}, request)
 	if callErr != nil {
-		logError(r, script, callErr)
-
 		return false, callErr
 	}
 
@@ -489,27 +480,13 @@ func executeScriptWithinContext(request *lua.LTable, script *LuaFilter, r *Reque
 
 	logResult(r, script, action, result)
 
-	if result != 0 {
-		err = fmt.Errorf("%v: %s", errors.ErrFilterFailed, script.Name)
-	}
-
 	if action {
 		return true, err
 	}
 
 	return false, err
 }
 
-// logError is a function that logs error information when a LuaFilter script fails during a Request session.
-// It logs the Session GUID, the name of the script, and the error message to the default error logger with an Error level.
-func logError(r *Request, script *LuaFilter, err error) {
-	level.Error(log.Logger).Log(
-		definitions.LogKeyGUID, r.Session,
-		"name", script.Name,
-		definitions.LogKeyMsg, err,
-	)
-}
-
 // logResult logs the output of a LuaFilter execution for a given request.
 // The outcome (ok or fail) and whether an action was taken is logged along with the session ID and script name.
 func logResult(r *Request, script *LuaFilter, action bool, ret int) {
@@ -523,9 +500,11 @@ func logResult(r *Request, script *LuaFilter, action bool, ret int) {
 		"result", resultMap[ret],
 	}
 
-	if r.Logs != nil {
-		for index := range *r.Logs {
-			logs = append(logs, (*r.Logs)[index])
+	if ret != 0 {
+		if r.Logs != nil {
+			for index := range *r.Logs {
+				logs = append(logs, (*r.Logs)[index])
+			}
 		}
 	}