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/cmd/get.go

@@ -17,12 +17,12 @@
 package cmd
 
 import (
-	"log"
 	"os"
 
 	"github.com/spf13/cobra"
 
 	"github.com/BBVA/kapow/internal/client"
+	"github.com/BBVA/kapow/internal/logger"
 )
 
 // GetCmd is the command line interface for get kapow data operation
@@ -38,7 +38,7 @@ var GetCmd = &cobra.Command{
 
 		err := client.GetData(dataURL, handler, args[0], os.Stdout)
 		if err != nil {
-			log.Fatal(err)
+			logger.L.Fatal(err)
 		}
 	},
 }

internal/cmd/route.go

@@ -18,10 +18,10 @@ package cmd
 
 import (
 	"io/ioutil"
-	"log"
 	"os"
 
 	"github.com/BBVA/kapow/internal/client"
+	"github.com/BBVA/kapow/internal/logger"
 
 	"github.com/spf13/cobra"
 )
@@ -39,7 +39,7 @@ func init() {
 			controlURL, _ := cmd.Flags().GetString("control-url")
 
 			if err := client.ListRoutes(controlURL, os.Stdout); err != nil {
-				log.Fatal(err)
+				logger.L.Fatal(err)
 			}
 		},
 	}
@@ -67,13 +67,13 @@ func init() {
 					buf, err = ioutil.ReadFile(commandFile)
 				}
 				if err != nil {
-					log.Fatal(err)
+					logger.L.Fatal(err)
 				}
 				command = string(buf)
 			}
 
 			if err := client.AddRoute(controlURL, urlPattern, method, entrypoint, command, os.Stdout); err != nil {
-				log.Fatal(err)
+				logger.L.Fatal(err)
 			}
 		},
 	}
@@ -91,7 +91,7 @@ func init() {
 			controlURL, _ := cmd.Flags().GetString("control-url")
 
 			if err := client.RemoveRoute(controlURL, args[0]); err != nil {
-				log.Fatal(err)
+				logger.L.Fatal(err)
 			}
 		},
 	}

internal/cmd/server.go

@@ -18,13 +18,12 @@ package cmd
 
 import (
 	"errors"
-	"fmt"
-	"log"
 	"os"
 	"os/exec"
 
 	"github.com/spf13/cobra"
 
+	"github.com/BBVA/kapow/internal/logger"
 	"github.com/BBVA/kapow/internal/server"
 )
 
@@ -62,9 +61,9 @@ var ServerCmd = &cobra.Command{
 			powfile := args[0]
 			_, err := os.Stat(powfile)
 			if os.IsNotExist(err) {
-				log.Fatalf("%s does not exist", powfile)
+				logger.L.Fatalf("%s does not exist", powfile)
 			}
-			log.Printf("Running powfile: %q\n", powfile)
+			logger.L.Printf("Running powfile: %q\n", powfile)
 			kapowCMD := exec.Command("bash", powfile)
 			kapowCMD.Stdout = os.Stdout
 			kapowCMD.Stderr = os.Stderr
@@ -72,10 +71,9 @@ var ServerCmd = &cobra.Command{
 
 			err = kapowCMD.Run()
 			if err != nil {
-				log.Fatal(err)
+				logger.L.Fatal(err)
 			}
-			fmt.Println()
+			logger.L.Printf("Done running powfile: %q\n", powfile)
-			log.Printf("Done running powfile: %q\n", powfile)
 		}
 
 		select {}

internal/cmd/set.go

@@ -18,11 +18,11 @@ package cmd
 
 import (
 	"io"
-	"log"
 	"os"
 	"strings"
 
 	"github.com/BBVA/kapow/internal/client"
+	"github.com/BBVA/kapow/internal/logger"
 
 	"github.com/spf13/cobra"
 )
@@ -47,7 +47,7 @@ var SetCmd = &cobra.Command{
 		}
 
 		if err := client.SetData(dataURL, handler, path, r); err != nil {
-			log.Fatal(err)
+			logger.L.Fatal(err)
 		}
 	},
 }

internal/logger/logger.go

@@ -0,0 +1,12 @@
+package logger
+
+import (
+	"log"
+	"os"
+)
+
+var L *log.Logger
+
+func init() {
+	L = log.New(os.Stderr, "", log.LstdFlags|log.Lmicroseconds|log.LUTC)
+}

internal/server/control/server.go

@@ -17,10 +17,11 @@
 package control
 
 import (
-	"log"
 	"net"
 	"net/http"
 	"sync"
+
+	"github.com/BBVA/kapow/internal/logger"
 )
 
 // Run Starts the control server listening in bindAddr
@@ -28,12 +29,12 @@ func Run(bindAddr string, wg *sync.WaitGroup) {
 
 	listener, err := net.Listen("tcp", bindAddr)
 	if err != nil {
-		log.Fatal(err)
+		logger.L.Fatal(err)
 	}
 
 	// Signal startup
-	log.Printf("ControlServer listening at %s\n", bindAddr)
+	logger.L.Printf("ControlServer listening at %s\n", bindAddr)
 	wg.Done()
 
-	log.Fatal(http.Serve(listener, configRouter()))
+	logger.L.Fatal(http.Serve(listener, configRouter()))
 }

internal/server/data/server.go

@@ -17,11 +17,11 @@
 package data
 
 import (
-	"log"
 	"net"
 	"net/http"
 	"sync"
 
+	"github.com/BBVA/kapow/internal/logger"
 	"github.com/BBVA/kapow/internal/server/httperror"
 	"github.com/gorilla/mux"
 )
@@ -87,12 +87,12 @@ func Run(bindAddr string, wg *sync.WaitGroup) {
 
 	listener, err := net.Listen("tcp", bindAddr)
 	if err != nil {
-		log.Fatal(err)
+		logger.L.Fatal(err)
 	}
 
 	// Signal startup
-	log.Printf("DataServer listening at %s\n", bindAddr)
+	logger.L.Printf("DataServer listening at %s\n", bindAddr)
 	wg.Done()
 
-	log.Fatal(http.Serve(listener, configRouter(rs)))
+	logger.L.Fatal(http.Serve(listener, configRouter(rs)))
 }

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())
 	}
 }

internal/server/user/mux/handlerbuilder_test.go

@@ -22,6 +22,7 @@ import (
 	"bytes"
 	"errors"
 	"io"
+	"log"
 	"net/http"
 	"net/http/httptest"
 	"reflect"
@@ -31,6 +32,7 @@ import (
 
 	"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"
@@ -207,7 +209,8 @@ func TestHandlerBuilderLogToLogHandlerWhenDebugIsEnabled(t *testing.T) {
 	route := model.Route{Debug: true}
 	var got string
 
-	logHandler = new(bytes.Buffer)
+	logHandler := new(bytes.Buffer)
+	logger.L = log.New(logHandler, "", log.LstdFlags)
 
 	spawner = func(h *model.Handler, out io.Writer, er io.Writer) error {
 		_, _ = out.Write([]byte("this is stdout"))
@@ -223,7 +226,7 @@ func TestHandlerBuilderLogToLogHandlerWhenDebugIsEnabled(t *testing.T) {
 	// cannot use a synchronization primitive to wait for them.  Sorry.
 	time.Sleep(1 * time.Second)
 
-	got = logHandler.(*bytes.Buffer).String()
+	got = logHandler.String()
 	if !strings.Contains(got, "this is stdout") {
 		t.Errorf("Stdout not preserved. Actual: %+q", got)
 	}
@@ -232,12 +235,12 @@ func TestHandlerBuilderLogToLogHandlerWhenDebugIsEnabled(t *testing.T) {
 	}
 }
 
-
 func TestHandlerBuilderDoesNotLogToLogHandlerWhenDebugIsDisabled(t *testing.T) {
 	data.Handlers = data.New()
 	route := model.Route{Debug: false}
 
-	logHandler = new(bytes.Buffer)
+	logHandler := new(bytes.Buffer)
+	logger.L = log.New(logHandler, "", log.LstdFlags)
 
 	spawner = func(h *model.Handler, out io.Writer, er io.Writer) error {
 		if out != nil {
@@ -257,7 +260,7 @@ func TestHandlerBuilderDoesNotLogToLogHandlerWhenDebugIsDisabled(t *testing.T) {
 	// cannot use a synchronization primitive to wait for them.  Sorry.
 	time.Sleep(1 * time.Second)
 
-	size := logHandler.(*bytes.Buffer).Len()
+	size := logHandler.Len()
 	if size != 0 {
 		t.Error("Something was logged to stderr with debug=false")
 	}

internal/server/user/server.go

@@ -21,11 +21,11 @@ import (
 	"crypto/x509"
 	"fmt"
 	"io/ioutil"
-	"log"
 	"net"
 	"net/http"
 	"sync"
 
+	"github.com/BBVA/kapow/internal/logger"
 	"github.com/BBVA/kapow/internal/server/user/mux"
 )
 
@@ -50,7 +50,7 @@ func Run(bindAddr string, wg *sync.WaitGroup, certFile, keyFile, cliCaFile strin
 
 	listener, err := net.Listen("tcp", bindAddr)
 	if err != nil {
-		log.Fatal(err)
+		logger.L.Fatal(err)
 	}
 
 	if (certFile != "") && (keyFile != "") {
@@ -62,28 +62,28 @@ func Run(bindAddr string, wg *sync.WaitGroup, certFile, keyFile, cliCaFile strin
 			var err error
 			Server.TLSConfig.ClientCAs, err = loadCertificatesFromFile(cliCaFile)
 			if err != nil {
-				log.Fatalf("UserServer failed to load CA certs: %s\n", err)
+				logger.L.Fatalf("UserServer failed to load CA certs: %s\n", err)
 			} else {
 				CAStore := "System store"
 				if Server.TLSConfig.ClientCAs != nil {
 					CAStore = cliCaFile
 				}
-				log.Printf("UserServer using CA certs from %s\n", CAStore)
+				logger.L.Printf("UserServer using CA certs from %s\n", CAStore)
 				Server.TLSConfig.ClientAuth = tls.RequireAndVerifyClientCert
 			}
 		}
 
 		// Signal startup
-		log.Printf("UserServer listening at %s\n", bindAddr)
+		logger.L.Printf("UserServer listening at %s\n", bindAddr)
 		wg.Done()
 
-		log.Fatal(Server.ServeTLS(listener, certFile, keyFile))
+		logger.L.Fatal(Server.ServeTLS(listener, certFile, keyFile))
 	} else {
 		// Signal startup
-		log.Printf("UserServer listening at %s\n", bindAddr)
+		logger.L.Printf("UserServer listening at %s\n", bindAddr)
 		wg.Done()
 
-		log.Fatal(Server.Serve(listener))
+		logger.L.Fatal(Server.Serve(listener))
 	}
 }
 

main.go

@@ -17,12 +17,10 @@
 package main
 
 import (
-	"fmt"
-	"os"
-
 	"github.com/spf13/cobra"
 
 	"github.com/BBVA/kapow/internal/cmd"
+	"github.com/BBVA/kapow/internal/logger"
 )
 
 func main() {
@@ -35,7 +33,6 @@ func main() {
 
 	err := kapowCmd.Execute()
 	if err != nil {
-		fmt.Println(err)
+		logger.L.Fatalln(err)
-		os.Exit(1)
 	}
 }