Add the function CreateLoggerFromConfig to create a logger from the c…

…onfig file (#33)

builder.go

@@ -0,0 +1,81 @@
+package log
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/no-src/log/level"
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	consoleLoggerType = "console"
+	fileLoggerType    = "file"
+	emptyLoggerType   = "empty"
+)
+
+// CreateLoggerFromConfig create a logger from config file
+func CreateLoggerFromConfig(configFile string) (Logger, error) {
+	data, err := os.ReadFile(configFile)
+	if err != nil {
+		return nil, err
+	}
+	var conf config
+	err = yaml.Unmarshal(data, &conf)
+	if err != nil {
+		return nil, err
+	}
+	return createLoggers(conf.Loggers)
+}
+
+func createLoggers(configs []loggerConfig) (Logger, error) {
+	var loggers []Logger
+	for _, logConf := range configs {
+		logger, err := createLogger(logConf)
+		if err != nil {
+			return nil, err
+		}
+		loggers = append(loggers, logger)
+	}
+	length := len(loggers)
+	if length == 0 {
+		return NewEmptyLogger(), nil
+	} else if length == 1 {
+		return loggers[0], nil
+	} else {
+		return NewMultiLogger(loggers...), nil
+	}
+}
+
+func createLogger(logConf loggerConfig) (Logger, error) {
+	var logger Logger
+	loggerType := strings.ToLower(logConf.Type)
+	switch loggerType {
+	case consoleLoggerType:
+		lvl, err := level.ParseLevel(logConf.Level)
+		if err != nil {
+			return nil, err
+		}
+		logger = NewConsoleLogger(lvl)
+	case fileLoggerType:
+		opt, err := toFileLoggerOption(logConf)
+		if err != nil {
+			return nil, err
+		}
+		fl, err := NewFileLoggerWithOption(opt)
+		if err != nil {
+			return nil, err
+		}
+		logger = fl
+	case emptyLoggerType:
+		logger = NewEmptyLogger()
+	default:
+		return nil, fmt.Errorf("unsupported logger type: %s", logConf.Type)
+	}
+
+	if loggerType != emptyLoggerType && logger != nil && logConf.Sample < 1 {
+		logger = NewDefaultSampleLogger(logger, logConf.Sample)
+	}
+	return logger, nil
+}

builder_test.go

@@ -0,0 +1,15 @@
+package log
+
+import (
+	"testing"
+)
+
+func TestCreateLoggerFromConfig(t *testing.T) {
+	logger, err := CreateLoggerFromConfig("./testdata/conf.yaml")
+	if err != nil {
+		t.Fatal(err)
+	}
+	InitDefaultLogger(logger)
+	defer Close()
+	testLogs(t)
+}

config.go

@@ -0,0 +1,38 @@
+package log
+
+import (
+	"time"
+
+	"github.com/no-src/log/level"
+	"github.com/no-src/log/option"
+)
+
+type config struct {
+	Loggers []loggerConfig `yaml:"loggers"`
+}
+
+type loggerConfig struct {
+	// common fields
+	Name       string  `yaml:"name"`
+	Type       string  `yaml:"type"`
+	Level      string  `yaml:"level"`
+	Format     string  `yaml:"format"`
+	TimeFormat string  `yaml:"time-format"`
+	Sample     float64 `yaml:"sample"`
+
+	// file logger fields
+	LogDir            string        `yaml:"log-dir"`
+	LogFilePrefix     string        `yaml:"log-file-prefix"`
+	AutoFlush         bool          `yaml:"auto-flush"`
+	AutoFlushInterval time.Duration `yaml:"auto-flush-interval"`
+	SplitByDate       bool          `yaml:"split-by-date"`
+}
+
+func toFileLoggerOption(logConf loggerConfig) (opt option.FileLoggerOption, err error) {
+	lvl, err := level.ParseLevel(logConf.Level)
+	if err != nil {
+		return opt, err
+	}
+	opt = option.NewFileLoggerOption(lvl, logConf.LogDir, logConf.LogFilePrefix, logConf.AutoFlush, logConf.AutoFlushInterval, logConf.SplitByDate)
+	return opt, nil
+}

go.mod

@@ -1,3 +1,5 @@
 module github.com/no-src/log
 
-go 1.19
+go 1.19
+
+require gopkg.in/yaml.v3 v3.0.1

go.sum

@@ -0,0 +1,4 @@
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

testdata/conf.yaml

@@ -0,0 +1,20 @@
+loggers:
+  - name: "console logger"
+    type: "console"
+    level: "debug"
+    format: "text"
+    time-format: "2006-01-02 15:04:05"
+    sample: 1
+  - name: "file logger"
+    type: "file"
+    level: "info"
+    format: "json"
+    time-format: "2006-01-02 15:04:05"
+    log-dir: "./logs"
+    log-file-prefix: "conf_logger_"
+    auto-flush: true
+    auto-flush-interval: 3s
+    split-by-date: true
+    sample: 0.5
+  - name: "empty logger"
+    type: "empty"