Only enable uuid generation warning when using registry handlers

Signed-off-by: Stephen J Day <stephen.day@docker.com>

cmd/registry/main.go

@@ -29,6 +29,7 @@ import (
 	_ "github.com/docker/distribution/registry/storage/driver/middleware/cloudfront"
 	_ "github.com/docker/distribution/registry/storage/driver/s3"
 	_ "github.com/docker/distribution/registry/storage/driver/swift"
+	"github.com/docker/distribution/uuid"
 	"github.com/docker/distribution/version"
 	gorhandlers "github.com/gorilla/handlers"
 	"github.com/yvasiyarov/gorelic"
@@ -62,6 +63,10 @@ func main() {
 		fatalf("error configuring logger: %v", err)
 	}
 
+	// inject a logger into the uuid library. warns us if there is a problem
+	// with uuid generation under low entropy.
+	uuid.Loggerf = context.GetLogger(ctx).Warnf
+
 	app := handlers.NewApp(ctx, *config)
 	handler := configureReporting(app)
 	handler = panicHandler(handler)

context/logger.go

@@ -3,8 +3,6 @@ package context
 import (
 	"fmt"
 
-	"github.com/docker/distribution/uuid"
-
 	"github.com/Sirupsen/logrus"
 )
 
@@ -101,8 +99,3 @@ func getLogrusLogger(ctx Context, keys ...interface{}) *logrus.Entry {
 
 	return logger.WithFields(fields)
 }
-
-func init() {
-	// inject a logger into the uuid library.
-	uuid.Loggerf = GetLogger(Background()).Warnf
-}

uuid/uuid.go

@@ -8,7 +8,6 @@ import (
 	"crypto/rand"
 	"fmt"
 	"io"
-	"log"
 	"os"
 	"syscall"
 	"time"
@@ -30,7 +29,7 @@ var (
 
 	// Loggerf can be used to override the default logging destination. Such
 	// log messages in this library should be logged at warning or higher.
-	Loggerf = log.Printf
+	Loggerf func(format string, args ...interface{}) = func(format string, args ...interface{}) {}
 )
 
 // UUID represents a UUID value. UUIDs can be compared and set to other values