log: reduce Request ID to a 6 byte random string

Request ID collisions are not a concern.

Issue: #1

cmd/texd/main.go

@@ -2,6 +2,8 @@ package main
 
 import (
 	"context"
+	"errors"
+	"flag"
 	"fmt"
 	"os"
 	"os/signal"
@@ -16,7 +18,7 @@ import (
 	"github.com/digineo/texd/service"
 	"github.com/digineo/texd/tex"
 	"github.com/docker/go-units"
-	flag "github.com/spf13/pflag"
+	"github.com/spf13/pflag"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
@@ -32,52 +34,60 @@ var opts = service.Options{
 }
 
 var (
-	engine     = tex.DefaultEngine.Name()
-	jobdir     = ""
-	pull       = false
-	logLevel   = zapcore.InfoLevel.String()
-	maxJobSize = units.BytesSize(float64(opts.MaxJobSize))
+	engine      = tex.DefaultEngine.Name()
+	jobdir      = ""
+	pull        = false
+	logLevel    = zapcore.InfoLevel.String()
+	maxJobSize  = units.BytesSize(float64(opts.MaxJobSize))
+	showVersion = false
 )
 
-var log = zap.L()
-
-func main() { //nolint:funlen
-	texd.PrintBanner(os.Stdout)
+func parseFlags() {
+	fs := pflag.NewFlagSet(os.Args[0], pflag.ContinueOnError)
+	fs.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage of %s:\n", os.Args[0])
+		fs.PrintDefaults()
+	}
 
-	flag.StringVarP(&opts.Addr, "listen-address", "b", opts.Addr,
+	fs.StringVarP(&opts.Addr, "listen-address", "b", opts.Addr,
 		"bind `address` for the HTTP API")
-	flag.StringVarP(&engine, "tex-engine", "X", engine,
+	fs.StringVarP(&engine, "tex-engine", "X", engine,
 		fmt.Sprintf("`name` of default TeX engine, acceptable values are: %v", tex.SupportedEngines()))
-	flag.DurationVarP(&opts.CompileTimeout, "compile-timeout", "t", opts.CompileTimeout,
+	fs.DurationVarP(&opts.CompileTimeout, "compile-timeout", "t", opts.CompileTimeout,
 		"maximum rendering time")
-	flag.IntVarP(&opts.QueueLength, "parallel-jobs", "P", opts.QueueLength,
+	fs.IntVarP(&opts.QueueLength, "parallel-jobs", "P", opts.QueueLength,
 		"maximum `number` of parallel rendereing jobs")
-	flag.StringVar(&maxJobSize, "max-job-size", maxJobSize,
+	fs.StringVar(&maxJobSize, "max-job-size", maxJobSize,
 		"maximum size of job, a value <= 0 disables check")
-	flag.DurationVarP(&opts.QueueTimeout, "queue-wait", "w", opts.QueueTimeout,
+	fs.DurationVarP(&opts.QueueTimeout, "queue-wait", "w", opts.QueueTimeout,
 		"maximum wait time in full rendering queue")
-	flag.StringVarP(&jobdir, "job-directory", "D", jobdir,
+	fs.StringVarP(&jobdir, "job-directory", "D", jobdir,
 		"`path` to base directory to place temporary jobs into (path must exist and it must be writable; defaults to the OS's temp directory)")
-	flag.BoolVar(&pull, "pull", pull, "always pull Docker images")
-	flag.StringVar(&logLevel, "log-level", logLevel,
+	fs.BoolVar(&pull, "pull", pull, "always pull Docker images")
+	fs.StringVar(&logLevel, "log-level", logLevel,
 		"set logging verbosity, acceptable values are: [debug, info, warn, error, dpanic, panic, fatal]")
-	versionRequested := flag.BoolP("version", "v", false, `print version information and exit`)
-	flag.Parse()
+	fs.BoolVarP(&showVersion, "version", "v", showVersion,
+		`print version information and exit`)
 
-	if *versionRequested {
-		printVersion()
+	switch err := fs.Parse(os.Args[1:]); {
+	case errors.Is(err, pflag.ErrHelp):
+		// pflag already has called fs.Usage
 		os.Exit(0)
+	case err != nil:
+		fmt.Fprintf(os.Stderr, "Error parsing flags:\n\t%v\n", err)
+		os.Exit(2)
 	}
+}
 
-	if lvl, err := zapcore.ParseLevel(logLevel); err != nil {
-		zap.L().Fatal("error parsing log level",
-			zap.String("flag", "--log-level"),
-			zap.Error(err))
-	} else if log, err = newLogger(lvl); err != nil {
-		zap.L().Fatal("error constructing logger",
-			zap.Error(err))
-	} else {
-		defer func() { _ = log.Sync() }()
+func main() {
+	texd.PrintBanner(os.Stdout)
+	parseFlags()
+	log, sync := setupLogger()
+	defer sync()
+
+	if showVersion {
+		printVersion()
+		os.Exit(0)
 	}
 
 	if err := tex.SetJobBaseDir(jobdir); err != nil {
@@ -115,14 +125,14 @@ func main() { //nolint:funlen
 	}
 
 	stop := service.Start(opts, log)
-	onExit(stop)
+	onExit(log, stop)
 }
 
 const exitTimeout = 10 * time.Second
 
 type stopFun func(context.Context) error
 
-func onExit(stopper ...stopFun) {
+func onExit(log *zap.Logger, stopper ...stopFun) {
 	exitCh := make(chan os.Signal, 2)
 	signal.Notify(exitCh, syscall.SIGINT, syscall.SIGTERM)
 	sig := <-exitCh
@@ -182,14 +192,34 @@ func printVersion() {
 	}
 }
 
-func newLogger(level zapcore.Level) (*zap.Logger, error) {
+func setupLogger() (*zap.Logger, func()) {
 	var cfg zap.Config
 	if texd.Development() {
 		cfg = zap.NewDevelopmentConfig()
 	} else {
 		cfg = zap.NewProductionConfig()
 	}
 
-	cfg.Level = zap.NewAtomicLevelAt(level)
-	return cfg.Build()
+	lvl, lvlErr := zapcore.ParseLevel(logLevel)
+	if lvlErr == nil {
+		cfg.Level = zap.NewAtomicLevelAt(lvl)
+	}
+
+	log, err := cfg.Build()
+	if err != nil {
+		// we don't have a logger yet, so logging the error
+		// proves to be complicatet :)
+		panic(err)
+	}
+
+	if lvlErr != nil {
+		log.Error("error parsing log level",
+			zap.String("flag", "--log-level"),
+			zap.Error(lvlErr))
+	}
+
+	zap.ReplaceGlobals(log)
+	return log, func() {
+		_ = log.Sync()
+	}
 }

go.mod

@@ -4,13 +4,15 @@ go 1.18
 
 require (
 	github.com/docker/docker v20.10.13+incompatible
+	github.com/docker/go-units v0.4.0
 	github.com/google/uuid v1.3.0
 	github.com/gorilla/handlers v1.5.1
 	github.com/gorilla/mux v1.8.0
 	github.com/moby/term v0.0.0-20210619224110-3f7ff695adc6
 	github.com/spf13/afero v1.8.1
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.7.0
+	go.uber.org/zap v1.21.0
 )
 
 require (
@@ -20,7 +22,6 @@ require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/docker/distribution v2.8.1+incompatible // indirect
 	github.com/docker/go-connections v0.4.0 // indirect
-	github.com/docker/go-units v0.4.0 // indirect
 	github.com/felixge/httpsnoop v1.0.2 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
@@ -32,7 +33,6 @@ require (
 	github.com/sirupsen/logrus v1.8.1 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	go.uber.org/zap v1.21.0 // indirect
 	golang.org/x/net v0.0.0-20220225172249-27dd8689420f // indirect
 	golang.org/x/sys v0.0.0-20220310020820-b874c991c1a5 // indirect
 	golang.org/x/text v0.3.7 // indirect

go.sum

@@ -110,6 +110,7 @@ github.com/armon/go-radix v0.0.0-20180808171621-7fddfc383310/go.mod h1:ufUuZ+zHj
 github.com/asaskevich/govalidator v0.0.0-20190424111038-f61b66f89f4a/go.mod h1:lB+ZfQJz7igIIfQNfa7Ml4HSf2uFQQRzpGGRXenZAgY=
 github.com/aws/aws-sdk-go v1.15.11/go.mod h1:mFuSZ37Z9YOHbQEwBWztmVzqXrEkub65tZoCYDt7FT0=
 github.com/benbjohnson/clock v1.0.3/go.mod h1:bGMdMPoPVvcYyt1gHDf4J2KE153Yf9BuiUKYMaxlTDM=
+github.com/benbjohnson/clock v1.1.0 h1:Q92kusRqC1XV2MjkWETPvjJVqKetz1OzxZB7mHJLju8=
 github.com/benbjohnson/clock v1.1.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
 github.com/beorn7/perks v0.0.0-20160804104726-4c0e84591b9a/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
@@ -876,6 +877,7 @@ go.uber.org/atomic v1.9.0 h1:ECmE8Bn/WFTYwEW/bpKD3M8VtR/zQVbavAoalC1PYyE=
 go.uber.org/atomic v1.9.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
 go.uber.org/goleak v1.1.10/go.mod h1:8a7PlsEVH3e/a/GLqe5IIrQx6GzcnRmZEufDUTk4A7A=
 go.uber.org/goleak v1.1.11/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
+go.uber.org/goleak v1.1.12 h1:gZAh5/EyT/HQwlpkCy6wTpqfH9H8Lz8zbm3dZh+OyzA=
 go.uber.org/goleak v1.1.12/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
 go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/0=
 go.uber.org/multierr v1.6.0/go.mod h1:cdWPpRnG4AhwMwsgIHip0KRBQjJy5kYEpYjJxpXp9iU=
@@ -1369,6 +1371,7 @@ gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.5/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
 gopkg.in/yaml.v2 v2.3.0/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
+gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
 gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20200615113413-eeeca48fe776/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

service/middleware/requestid.go

@@ -2,9 +2,11 @@ package middleware
 
 import (
 	"context"
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
 	"net/http"
 
-	"github.com/google/uuid"
 	"go.uber.org/zap"
 )
 
@@ -14,9 +16,17 @@ type contextKey string
 
 const ContextKey = contextKey("request-id")
 
+func generateRequestId() string {
+	b := make([]byte, 6)
+	if _, err := rand.Read(b); err != nil {
+		panic(fmt.Errorf("rand error: %w", err))
+	}
+	return base64.RawURLEncoding.EncodeToString(b)
+}
+
 func RequestID(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		id := uuid.Must(uuid.NewRandom()).String()
+		id := generateRequestId()
 		r = r.WithContext(context.WithValue(r.Context(), ContextKey, id))
 		w.Header().Set(HeaderKey, id)
 
@@ -30,9 +40,8 @@ func GetRequestID(r *http.Request) (string, bool) {
 }
 
 func RequestIDField(ctx context.Context) zap.Field {
-	id, ok := ctx.Value(ContextKey).(string)
-	if !ok {
-		id = "-"
+	if id, ok := ctx.Value(ContextKey).(string); ok {
+		return zap.String("request-id", id)
 	}
-	return zap.String("request-id", id)
+	return zap.Skip()
 }