Merge pull request containerd#1609 from crosbymichael/attach-docs

AkihiroSuda · web-flow · commit a8426ed9e785 · 2017-10-08T11:24:57.000+09:00
Add docs around multiple attach
diff --git a/container.go b/container.go
@@ -32,6 +32,9 @@ type Container interface {
 	//
 	// If IOAttach options are passed the client will reattach to the IO for the running
 	// task. If no task exists for the container a NotFound error is returned
+	//
+	// Clients must make sure that only one reader is attached to the task and consuming
+	// the output from the task's fifos
 	Task(context.Context, IOAttach) (Task, error)
 	// Image returns the image that the container is based on
 	Image(context.Context) (Image, error)
diff --git a/io.go b/io.go
@@ -68,6 +68,10 @@ func (c *cio) Close() error {
 type IOCreation func(id string) (IO, error)
 
 // IOAttach allows callers to reattach to running tasks
+//
+// There should only be one reader for a task's IO set
+// because fifo's can only be read from one reader or the output
+// will be sent only to the first reads
 type IOAttach func(*FIFOSet) (IO, error)
 
 // NewIO returns an IOCreation that will provide IO sets without a terminal
