cmd/dex: add logging config and serve logger for different modules.

cmd/dex/config.go

@@ -8,6 +8,7 @@ import (
 
 	"golang.org/x/crypto/bcrypt"
 
+	"github.com/Sirupsen/logrus"
 	"github.com/coreos/dex/connector"
 	"github.com/coreos/dex/connector/github"
 	"github.com/coreos/dex/connector/ldap"
@@ -29,6 +30,7 @@ type Config struct {
 	OAuth2     OAuth2      `json:"oauth2"`
 	GRPC       GRPC        `json:"grpc"`
 	Expiry     Expiry      `json:"expiry"`
+	Logger     Logger      `json:"logger"`
 
 	Frontend server.WebConfig `json:"frontend"`
 
@@ -119,7 +121,7 @@ type Storage struct {
 
 // StorageConfig is a configuration that can create a storage.
 type StorageConfig interface {
-	Open() (storage.Storage, error)
+	Open(logrus.FieldLogger) (storage.Storage, error)
 }
 
 var storages = map[string]func() StorageConfig{
@@ -170,7 +172,7 @@ type Connector struct {
 
 // ConnectorConfig is a configuration that can open a connector.
 type ConnectorConfig interface {
-	Open() (connector.Connector, error)
+	Open(logrus.FieldLogger) (connector.Connector, error)
 }
 
 var connectors = map[string]func() ConnectorConfig{
@@ -223,3 +225,12 @@ type Expiry struct {
 	// IdTokens defines the duration of time for which the IdTokens will be valid.
 	IDTokens string `json:"idTokens"`
 }
+
+// Logger holds configuration required to customize logging for dex.
+type Logger struct {
+	// Level sets logging level severity.
+	Level string `json:"level"`
+
+	// Format specifies the format to be used for logging.
+	Format string `json:"format"`
+}

cmd/dex/config_test.go

@@ -59,6 +59,10 @@ staticPasswords:
 expiry:
   signingKeys: "6h"
   idTokens: "24h"
+
+logger:
+  level: "debug"
+  format: "json"
 `)
 
 	want := Config{
@@ -120,6 +124,10 @@ expiry:
 			SigningKeys: "6h",
 			IDTokens:    "24h",
 		},
+		Logger: Logger{
+			Level:  "debug",
+			Format: "json",
+		},
 	}
 
 	var c Config

cmd/dex/serve.go

@@ -9,8 +9,11 @@ import (
 	"log"
 	"net"
 	"net/http"
+	"os"
+	"strings"
 	"time"
 
+	"github.com/Sirupsen/logrus"
 	"github.com/ghodss/yaml"
 	"github.com/spf13/cobra"
 	"golang.org/x/net/context"
@@ -111,6 +114,8 @@ func serve(cmd *cobra.Command, args []string) error {
 		}
 	}
 
+	logger, _ := newLogger(c.Logger.Level, c.Logger.Format)
+
 	connectors := make([]server.Connector, len(c.Connectors))
 	for i, conn := range c.Connectors {
 		if conn.ID == "" {
@@ -119,7 +124,8 @@ func serve(cmd *cobra.Command, args []string) error {
 		if conn.Config == nil {
 			return fmt.Errorf("no config field for connector %q", conn.ID)
 		}
-		c, err := conn.Config.Open()
+		connectorLogger := logger.WithField("connector", conn.Name)
+		c, err := conn.Config.Open(connectorLogger)
 		if err != nil {
 			return fmt.Errorf("open %s: %v", conn.ID, err)
 		}
@@ -130,7 +136,7 @@ func serve(cmd *cobra.Command, args []string) error {
 		}
 	}
 
-	s, err := c.Storage.Config.Open()
+	s, err := c.Storage.Config.Open(logger)
 	if err != nil {
 		return fmt.Errorf("initializing storage: %v", err)
 	}
@@ -153,6 +159,7 @@ func serve(cmd *cobra.Command, args []string) error {
 		Storage:                s,
 		Web:                    c.Frontend,
 		EnablePasswordDB:       c.EnablePasswordDB,
+		Logger:                 logger,
 	}
 	if c.Expiry.SigningKeys != "" {
 		signingKeys, err := time.ParseDuration(c.Expiry.SigningKeys)
@@ -203,3 +210,33 @@ func serve(cmd *cobra.Command, args []string) error {
 
 	return <-errc
 }
+
+func newLogger(level string, format string) (logrus.FieldLogger, error) {
+	var logLevel logrus.Level
+	switch strings.ToLower(level) {
+	case "debug":
+		logLevel = logrus.DebugLevel
+	case "", "info":
+		logLevel = logrus.InfoLevel
+	case "error":
+		logLevel = logrus.ErrorLevel
+	default:
+		return nil, fmt.Errorf("unsupported logLevel: %s", level)
+	}
+
+	var formatter logrus.Formatter
+	switch strings.ToLower(format) {
+	case "", "text":
+		formatter = &logrus.TextFormatter{DisableColors: true}
+	case "json":
+		formatter = &logrus.JSONFormatter{}
+	default:
+		return nil, fmt.Errorf("unsupported logger format: %s", format)
+	}
+
+	return &logrus.Logger{
+		Out:       os.Stderr,
+		Formatter: formatter,
+		Level:     logLevel,
+	}, nil
+}