Merge pull request #393 from hellofresh/patch/early-logger-writer-init

Init log writer as early as possible

cmd/init.go

@@ -1,12 +1,15 @@
 package cmd
 
 import (
+	"io/ioutil"
 	"os"
 	"path/filepath"
+	"strings"
 	"time"
 
 	"github.com/hellofresh/janus/pkg/config"
 	obs "github.com/hellofresh/janus/pkg/observability"
+	"github.com/hellofresh/logging-go"
 	"github.com/hellofresh/stats-go"
 	"github.com/hellofresh/stats-go/bucket"
 	"github.com/hellofresh/stats-go/client"
@@ -23,6 +26,19 @@ var (
 	statsClient  client.Client
 )
 
+func initLogWriterEarly() {
+	switch logging.LogWriter(strings.ToLower(os.Getenv("LOG_WRITER"))) {
+	case logging.StdOut:
+		log.SetOutput(os.Stdout)
+	case logging.Discard:
+		log.SetOutput(ioutil.Discard)
+	case logging.StdErr:
+		fallthrough
+	default:
+		log.SetOutput(os.Stderr)
+	}
+}
+
 func initConfig() {
 	var err error
 	globalConfig, err = config.Load(configFile)

cmd/server.go

@@ -52,6 +52,11 @@ func NewServerStartCmd(ctx context.Context) *cobra.Command {
 
 // RunServerStart is the run command to start Janus
 func RunServerStart(ctx context.Context, opts *ServerStartOptions) error {
+	// all the logging configurations are initialised in initLog() later,
+	// but we try to initialise Writer (STDIN/STDERR/etc.) as early as possible manually
+	// to avoid loosing logs in systems heavily relying on them (e.g. running in docker)
+	initLogWriterEarly()
+
 	log.WithField("version", version).Info("Janus starting...")
 
 	initConfig()

cmd/version.go

@@ -2,7 +2,6 @@ package cmd
 
 import (
 	"context"
-	"fmt"
 
 	"github.com/spf13/cobra"
 )
@@ -16,7 +15,7 @@ func NewVersionCmd(ctx context.Context) *cobra.Command {
 		Short:   "Print the version information",
 		Aliases: []string{"v"},
 		Run: func(cmd *cobra.Command, args []string) {
-			fmt.Printf("janus %s\n", version)
+			cmd.Printf("janus %s\n", version)
 		},
 	}
 }