vendoring dependencies

vendor/github.com/docker/libcompose/logger/null.go

@@ -0,0 +1,18 @@
+package logger
+
+// NullLogger is a logger.Logger and logger.Factory implementation that does nothing.
+type NullLogger struct {
+}
+
+// Out is a no-op function.
+func (n *NullLogger) Out(_ []byte) {
+}
+
+// Err is a no-op function.
+func (n *NullLogger) Err(_ []byte) {
+}
+
+// Create implements logger.Factory and returns a NullLogger.
+func (n *NullLogger) Create(_ string) Logger {
+	return &NullLogger{}
+}

vendor/github.com/docker/libcompose/logger/types.go

@@ -0,0 +1,29 @@
+package logger
+
+// Factory defines methods a factory should implement, to create a Logger
+// based on the specified name.
+type Factory interface {
+	Create(name string) Logger
+}
+
+// Logger defines methods to implement for being a logger.
+type Logger interface {
+	Out(bytes []byte)
+	Err(bytes []byte)
+}
+
+// Wrapper is a wrapper around Logger that implements the Writer interface,
+// mainly use by docker/pkg/stdcopy functions.
+type Wrapper struct {
+	Err    bool
+	Logger Logger
+}
+
+func (l *Wrapper) Write(bytes []byte) (int, error) {
+	if l.Err {
+		l.Logger.Err(bytes)
+	} else {
+		l.Logger.Out(bytes)
+	}
+	return len(bytes), nil
+}