consider $LOG_FORMAT & $LOG_LEVEL when initializing loggers

Author: azazeal

logger.go

@@ -100,13 +100,13 @@ func New(name string, opts ...Option) (*Logger, error) {
 	// Logs info and debug to stdout
 	outWriter := zapcore.Lock(os.Stdout)
 	outLevel := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
-		return lvl < zapcore.WarnLevel
+		return lvl >= o.Level && lvl < zapcore.WarnLevel
 	})
 
 	// Logs warning and errors to stderr
 	errWriter := zapcore.Lock(os.Stderr)
 	errLevel := zap.LevelEnablerFunc(func(lvl zapcore.Level) bool {
-		return lvl >= zapcore.WarnLevel
+		return lvl >= o.Level && lvl >= zapcore.WarnLevel
 	})
 
 	// Create zap.Logger

options.go

@@ -2,27 +2,47 @@ package logging
 
 import (
 	"encoding/json"
+	"os"
 
 	"github.com/pkg/errors"
+	"go.uber.org/zap/zapcore"
 )
 
 type options struct {
-	Format       string `json:"format"`
-	TraceHeader  string `json:"traceHeader"`
-	LogRequests  bool   `json:"logRequests"`
-	LogResponses bool   `json:"logResponses"`
-	TimeFormat   string `json:"timeFormat"`
-	CallerSkip   int    `json:"callerSkip"`
+	Format       string        `json:"format"`
+	Level        zapcore.Level `json:"level"`
+	TraceHeader  string        `json:"traceHeader"`
+	LogRequests  bool          `json:"logRequests"`
+	LogResponses bool          `json:"logResponses"`
+	TimeFormat   string        `json:"timeFormat"`
+	CallerSkip   int           `json:"callerSkip"`
 }
 
 func defaultOptions() *options {
 	return &options{
-		Format:      "json",
+		Format:      formatFromEnv(),
+		Level:       levelFromEnv(),
 		TraceHeader: DefaultTraceHeader,
 		CallerSkip:  1,
 	}
 }
 
+func formatFromEnv() (format string) {
+	if format = os.Getenv("LOG_FORMAT"); format == "" {
+		format = "json"
+	}
+	return
+}
+
+func levelFromEnv() (level zapcore.Level) {
+	v := os.Getenv("LOG_LEVEL")
+	if err := level.UnmarshalText([]byte(v)); err != nil {
+		level = zapcore.InfoLevel
+	}
+
+	return
+}
+
 func (o *options) apply(opts []Option) (err error) {
 	for _, fn := range opts {
 		if err = fn(o); err != nil {
@@ -101,3 +121,11 @@ func WithCallerSkip(skip int) Option {
 		return nil
 	}
 }
+
+// WithLogLevel sets the verbosity of the logger.
+func WithLogLevel(level zapcore.Level) Option {
+	return func(o *options) error {
+		o.Level = level
+		return nil
+	}
+}