moving log selection to options

README.md

@@ -158,9 +158,10 @@ For more details, see the examples.
 ## Configuration
 
 ### Logging
-The default format is generic JSON. The log format can be configured by setting the `LOG_FORMAT` environment variable. The supported formats are:
-- "stackdriver"
-- "console"
+The log format can be configured by providing an `Option` on initialization. The supported formats are:
+- JSON (default)
+- Stackdriver
+- Console
 
 ## Contributions
 

logger.go

@@ -2,51 +2,24 @@ package svc
 
 import (
 	"os"
-	"strings"
 	"time"
 
-	"github.com/blendle/zapdriver"
 	"go.uber.org/zap"
 	"go.uber.org/zap/zapcore"
 )
 
-func newLogger(name, version string, level zapcore.Level) (*zap.Logger, zap.AtomicLevel) {
-	logFormat := strings.ToLower(os.Getenv("LOG_FORMAT"))
-
+func newLogger(level zapcore.Level, encoder zapcore.Encoder) (*zap.Logger, zap.AtomicLevel) {
 	atom := zap.NewAtomicLevel()
 	atom.SetLevel(level)
 
-	// stackdriver
-	if logFormat == "stackdriver" {
-		logger := zap.New(zapcore.NewSampler(zapcore.NewCore(
-			zapcore.NewJSONEncoder(zapdriver.NewProductionEncoderConfig()),
-			zapcore.Lock(os.Stdout),
-			atom,
-		), time.Second, 100, 10),
-			zap.ErrorOutput(zapcore.Lock(os.Stderr)),
-			zap.AddCaller(),
-		)
-		logger = logger.With(zapdriver.ServiceContext(name), zapdriver.Label("version", version))
-		return logger, atom
-	}
-
-	// console text logger or fallback to default generic JSON
-	var enc zapcore.Encoder
-	if logFormat == "console" {
-		config := zap.NewProductionEncoderConfig()
-		config.EncodeTime = zapcore.RFC3339TimeEncoder
-		enc = zapcore.NewConsoleEncoder(config)
-	} else {
-		enc = zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig())
-	}
 	logger := zap.New(zapcore.NewSampler(zapcore.NewCore(
-		enc,
+		encoder,
 		zapcore.Lock(os.Stdout),
 		atom,
 	), time.Second, 100, 10),
 		zap.ErrorOutput(zapcore.Lock(os.Stderr)),
 		zap.AddCaller(),
-		zap.Fields(zap.String("app", name), zap.String("version", version)),
 	)
+
 	return logger, atom
 }

options.go

@@ -7,6 +7,7 @@ import (
 	"net/http/pprof"
 	"time"
 
+	"github.com/blendle/zapdriver"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"go.uber.org/zap"
@@ -35,11 +36,9 @@ func WithRouter(router *http.ServeMux) Option {
 	}
 }
 
-// WithProductionLogger is an option that uses a zap Logger with configurations
-// set meant to be used for production.
-func WithProductionLogger() Option {
+// WithLogger is an option that allows you to provide your own customized logger.
+func WithLogger(logger *zap.Logger, atom zap.AtomicLevel) Option {
 	return func(s *SVC) error {
-		logger, atom := newLogger(s.Name, s.Version, zapcore.InfoLevel)
 		return assignLogger(s, logger, atom)
 	}
 }
@@ -48,7 +47,55 @@ func WithProductionLogger() Option {
 // configurations set meant to be used for development.
 func WithDevelopmentLogger() Option {
 	return func(s *SVC) error {
-		logger, atom := newLogger(s.Name, s.Version, zapcore.DebugLevel)
+		logger, atom := newLogger(
+			zapcore.DebugLevel,
+			zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
+		)
+		logger.With(zap.String("app", s.Name), zap.String("version", s.Version))
+		return assignLogger(s, logger, atom)
+	}
+}
+
+// WithProductionLogger is an option that uses a zap Logger with configurations
+// set meant to be used for production.
+func WithProductionLogger() Option {
+	return func(s *SVC) error {
+		logger, atom := newLogger(
+			zapcore.InfoLevel,
+			zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
+		)
+		logger.With(zap.String("app", s.Name), zap.String("version", s.Version))
+		return assignLogger(s, logger, atom)
+	}
+}
+
+// WithConsoleLogger is an option that uses a zap Logger with configurations
+// set meant to be used for debugging in the console.
+func WithConsoleLogger(level zapcore.Level) Option {
+	return func(s *SVC) error {
+
+		config := zap.NewProductionEncoderConfig()
+		config.EncodeTime = zapcore.RFC3339TimeEncoder
+
+		logger, atom := newLogger(
+			level,
+			zapcore.NewConsoleEncoder(config),
+		)
+		logger.With(zap.String("app", s.Name), zap.String("version", s.Version))
+		return assignLogger(s, logger, atom)
+	}
+}
+
+// WithStackdriverLogger is an option that uses a zap Logger with configurations
+// set meant to be used for production and is compliant with the GCP/Stackdriver format.
+func WithStackdriverLogger(level zapcore.Level) Option {
+	return func(s *SVC) error {
+
+		logger, atom := newLogger(
+			level,
+			zapcore.NewJSONEncoder(zapdriver.NewProductionEncoderConfig()),
+		)
+		logger.With(zapdriver.ServiceContext(s.Name), zapdriver.Label("version", s.Version))
 		return assignLogger(s, logger, atom)
 	}
 }