refactor: use a common logger for consistency

All kapow messages will end up in stderr (incl. debug mode).
stdout is reserved for the access logs.

Co-authored-by: Roberto Abdelkader Martínez Pérez <robertomartinezp@gmail.com>

internal/server/user/mux/handlerbuilder.go

@@ -18,13 +18,12 @@ package mux
 
 import (
 	"bufio"
-	"log"
 	"net/http"
-	"io"
 	"os"
 
 	"github.com/google/uuid"
 
+	"github.com/BBVA/kapow/internal/logger"
 	"github.com/BBVA/kapow/internal/server/data"
 	"github.com/BBVA/kapow/internal/server/model"
 	"github.com/BBVA/kapow/internal/server/user/spawn"
@@ -32,7 +31,6 @@ import (
 
 var spawner = spawn.Spawn
 var idGenerator = uuid.NewUUID
-var logHandler io.Writer = os.Stdout
 
 func handlerBuilder(route model.Route) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -57,14 +55,14 @@ func handlerBuilder(route model.Route) http.Handler {
 			stdOutR, stdOutW, err = os.Pipe()
 			defer stdOutW.Close()
 			if err != nil {
-				log.Println(err)
+				logger.L.Println(err)
 				return
 			}
 			var stdErrR, stdErrW *os.File
 			stdErrR, stdErrW, err = os.Pipe()
 			defer stdErrW.Close()
 			if err != nil {
-				log.Println(err)
+				logger.L.Println(err)
 				return
 			}
 
@@ -76,9 +74,8 @@ func handlerBuilder(route model.Route) http.Handler {
 			err = spawner(h, nil, nil)
 		}
 
-
 		if err != nil {
-			log.Println(err)
+			logger.L.Println(err)
 		}
 
 	})
@@ -86,9 +83,8 @@ func handlerBuilder(route model.Route) http.Handler {
 
 func logStream(handlerId string, streamName string, stream *os.File) {
 	defer stream.Close()
-	execLog := log.New(logHandler, "", log.Ldate|log.Ltime|log.LUTC|log.Lmicroseconds)
 	scanner := bufio.NewScanner(stream)
 	for scanner.Scan() {
-		execLog.Printf("%s %s: %s", handlerId, streamName, scanner.Text())
+		logger.L.Printf("%s %s: %s", handlerId, streamName, scanner.Text())
 	}
 }