diff --git a/cmd/registry/main.go b/cmd/registry/main.go index 66ce6367..efea4d15 100644 --- a/cmd/registry/main.go +++ b/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) diff --git a/context/context.go b/context/context.go index 7a3a70e0..23cbf5b5 100644 --- a/context/context.go +++ b/context/context.go @@ -1,6 +1,8 @@ package context import ( + "sync" + "github.com/docker/distribution/uuid" "golang.org/x/net/context" ) @@ -14,11 +16,19 @@ type Context interface { // provided as the main background context. type instanceContext struct { Context - id string // id of context, logged as "instance.id" + id string // id of context, logged as "instance.id" + once sync.Once // once protect generation of the id } func (ic *instanceContext) Value(key interface{}) interface{} { if key == "instance.id" { + ic.once.Do(func() { + // We want to lazy initialize the UUID such that we don't + // call a random generator from the package initialization + // code. For various reasons random could not be available + // https://github.com/docker/distribution/issues/782 + ic.id = uuid.Generate().String() + }) return ic.id } @@ -27,7 +37,6 @@ func (ic *instanceContext) Value(key interface{}) interface{} { var background = &instanceContext{ Context: context.Background(), - id: uuid.Generate().String(), } // Background returns a non-nil, empty Context. The background context diff --git a/context/logger.go b/context/logger.go index b0f0c508..78e4212a 100644 --- a/context/logger.go +++ b/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 -} diff --git a/uuid/uuid.go b/uuid/uuid.go index 02de33f2..d433ccaf 100644 --- a/uuid/uuid.go +++ b/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{}) {} ) // UUID represents a UUID value. UUIDs can be compared and set to other values