simplify logging

pkg/app/app.go

@@ -3,11 +3,12 @@ package app
 import (
 	"context"
 	"errors"
+	"io"
+	"log"
 	"os"
 
 	"github.com/peterbourgon/ff/v4"
 	"github.com/peterbourgon/ff/v4/ffhelp"
-	"go.uber.org/zap"
 )
 
 const (
@@ -16,21 +17,24 @@ const (
 
 // struct for receivers to use common app pieces
 type app struct {
-	logger *zap.SugaredLogger
-	cmd    *ff.Command
-	config *config
+	stdLogger   *log.Logger
+	debugLogger *log.Logger
+	errLogger   *log.Logger
+	cmd         *ff.Command
+	config      *config
 }
 
 // actual application start
 func Start(args []string) {
-	// make app w/ initial logger pre-config
-	initLogLevel := "debug"
+	// make app w/ logger
 	app := &app{
-		logger: makeZapLogger(&initLogLevel),
+		stdLogger:   log.New(os.Stdout, "", 0),
+		debugLogger: log.New(io.Discard, "", 0), // discard debug logging by default
+		errLogger:   log.New(os.Stderr, "", 0),
 	}
 
 	// log start
-	app.logger.Infof("apc-p15-tool v%s", appVersion)
+	app.stdLogger.Printf("apc-p15-tool v%s", appVersion)
 
 	// get os.Args if args unspecified in func
 	if args == nil {
@@ -40,8 +44,8 @@ func Start(args []string) {
 	// get & parse config
 	err := app.getConfig(args)
 
-	// re-init logger with configured log level
-	app.logger = makeZapLogger(app.config.logLevel)
+	// if debug logging, make real debug logger
+	app.debugLogger = log.New(os.Stdout, "debug: ", 0)
 
 	// deal with config err (after logger re-init)
 	if err != nil {
@@ -49,7 +53,7 @@ func Start(args []string) {
 
 		if errors.Is(err, ff.ErrHelp) {
 			// help explicitly requested
-			app.logger.Info("\n\n", ffhelp.Command(app.cmd))
+			app.stdLogger.Printf("\n%s\n", ffhelp.Command(app.cmd))
 
 		} else if errors.Is(err, ff.ErrDuplicateFlag) ||
 			errors.Is(err, ff.ErrUnknownFlag) ||
@@ -57,13 +61,13 @@ func Start(args []string) {
 			errors.Is(err, ErrExtraArgs) {
 			// other error that suggests user needs to see help
 			exitCode = 1
-			app.logger.Error(err)
-			app.logger.Info("\n\n", ffhelp.Command(app.cmd))
+			app.errLogger.Print(err)
+			app.stdLogger.Printf("\n%s\n", ffhelp.Command(app.cmd))
 
 		} else {
 			// any other error
 			exitCode = 1
-			app.logger.Error(err)
+			app.errLogger.Print(err)
 		}
 
 		os.Exit(exitCode)
@@ -74,9 +78,14 @@ func Start(args []string) {
 	err = app.cmd.Run(context.Background())
 	if err != nil {
 		exitCode = 1
-		app.logger.Error(err)
+		app.errLogger.Print(err)
+
+		// if extra args, show help
+		if errors.Is(err, ErrExtraArgs) {
+			app.stdLogger.Printf("\n%s\n", ffhelp.Command(app.cmd))
+		}
 	}
 
-	app.logger.Info("apc-p15-tool done")
+	app.stdLogger.Print("apc-p15-tool done")
 	os.Exit(exitCode)
 }

pkg/app/cmd_create.go

@@ -41,7 +41,7 @@ func (app *app) cmdCreate(_ context.Context, args []string) error {
 		return fmt.Errorf("create: failed to write apc p15 file (%s)", err)
 	}
 
-	app.logger.Infof("create: apc p15 file %s written to disk", fileName)
+	app.stdLogger.Printf("create: apc p15 file %s written to disk", fileName)
 
 	return nil
 }

pkg/app/cmd_install.go

@@ -67,8 +67,8 @@ func (app *app) cmdInstall(cmdCtx context.Context, args []string) error {
 		// log fingerprint for debugging
 		actualHashB64 := base64.RawStdEncoding.EncodeToString(actualHash)
 		actualHashHex := hex.EncodeToString(actualHash)
-		app.logger.Debugf("ssh: remote server key fingerprint (b64): %s", actualHashB64)
-		app.logger.Debugf("ssh: remote server key fingerprint (hex): %s", actualHashHex)
+		app.debugLogger.Printf("ssh: remote server key fingerprint (b64): %s", actualHashB64)
+		app.debugLogger.Printf("ssh: remote server key fingerprint (hex): %s", actualHashHex)
 
 		// allow base64 format
 		if actualHashB64 == *app.config.install.fingerprint {
@@ -120,7 +120,7 @@ func (app *app) cmdInstall(cmdCtx context.Context, args []string) error {
 	}
 
 	// done
-	app.logger.Infof("install: apc p15 file installed on %s", *app.config.install.hostAndPort)
+	app.stdLogger.Printf("install: apc p15 file installed on %s", *app.config.install.hostAndPort)
 
 	return nil
 }

pkg/app/config.go

@@ -25,8 +25,8 @@ type keyCertPemCfg struct {
 
 // app's config options from user
 type config struct {
-	logLevel *string
-	create   struct {
+	debugLogging *bool
+	create       struct {
 		keyCertPemCfg
 		outFilePath *string
 	}
@@ -54,8 +54,7 @@ func (app *app) getConfig(args []string) error {
 	// apc-p15-tool -- root command
 	rootFlags := ff.NewFlagSet("apc-p15-tool")
 
-	cfg.logLevel = rootFlags.StringEnum('l', "loglevel", "log level: debug, info, warn, error, dpanic, panic, or fatal",
-		"info", "debug", "warn", "error", "dpanic", "panic", "fatal")
+	cfg.debugLogging = rootFlags.BoolLong("debug", "set this flag to enable additional debug logging messages")
 
 	rootCmd := &ff.Command{
 		Name:  "apc-p15-tool",

pkg/app/logger.go

@@ -1,47 +0,0 @@
-package app
-
-import (
-	"os"
-
-	"go.uber.org/zap"
-	"go.uber.org/zap/zapcore"
-)
-
-// makeZapLogger creates a logger for the app; if log level is nil or does not parse
-// the default 'Info' level will be used.
-func makeZapLogger(logLevel *string) *zap.SugaredLogger {
-	// default info level
-	zapLevel := zapcore.InfoLevel
-	var parseErr error
-
-	// try to parse specified level (if there is one)
-	if logLevel != nil {
-		parseLevel, err := zapcore.ParseLevel(*logLevel)
-		if err != nil {
-			parseErr = err
-		} else {
-			zapLevel = parseLevel
-		}
-	}
-
-	// make zap config
-	config := zap.NewProductionEncoderConfig()
-	config.EncodeTime = zapcore.ISO8601TimeEncoder
-	config.LineEnding = "\n"
-
-	// no stack trace
-	config.StacktraceKey = ""
-
-	// make logger
-	consoleEncoder := zapcore.NewConsoleEncoder(config)
-	core := zapcore.NewCore(consoleEncoder, zapcore.AddSync(os.Stdout), zapLevel)
-
-	logger := zap.New(core, zap.AddCaller(), zap.AddStacktrace(zapcore.ErrorLevel)).Sugar()
-
-	// log deferred parse error if there was one
-	if logLevel != nil && parseErr != nil {
-		logger.Errorf("failed to parse requested log level \"%s\" (%s)", *logLevel, parseErr)
-	}
-
-	return logger
-}

pkg/app/pem_to_p15.go

@@ -7,7 +7,7 @@ import (
 
 // pemToAPCP15 reads the specified pem files and returns the apc p15 bytes
 func (app *app) pemToAPCP15(keyPem, certPem []byte, parentCmdName string) ([]byte, error) {
-	app.logger.Infof("%s: making apc p15 file from pem", parentCmdName)
+	app.stdLogger.Printf("%s: making apc p15 file from pem", parentCmdName)
 
 	// make p15 struct
 	p15, err := pkcs15.ParsePEMToPKCS15(keyPem, certPem)
@@ -15,7 +15,7 @@ func (app *app) pemToAPCP15(keyPem, certPem []byte, parentCmdName string) ([]byt
 		return nil, fmt.Errorf("%s: failed to parse pem files (%w)", parentCmdName, err)
 	}
 
-	app.logger.Infof("%s: successfully loaded pem files", parentCmdName)
+	app.stdLogger.Printf("%s: successfully loaded pem files", parentCmdName)
 
 	// make file bytes
 	p15File, err := p15.ToP15File()
@@ -32,7 +32,7 @@ func (app *app) pemToAPCP15(keyPem, certPem []byte, parentCmdName string) ([]byt
 	// combine header with file
 	apcFile := append(apcHeader, p15File...)
 
-	app.logger.Infof("%s: apc p15 file data succesfully generated", parentCmdName)
+	app.stdLogger.Printf("%s: apc p15 file data succesfully generated", parentCmdName)
 
 	return apcFile, nil
 }