TestAttachSlowContainer

test.go

func TestAttachSlowContainer(t *testing.T) {
	defer deleteAllContainers()
  c := exec.Command("/bin/bash", "-c", dockerBinary+` run --rm -i busybox /bin/sh -c "dd if=/dev/zero of=/foo bs=1024 count=1000 &>/dev/null; catv /foo"`)
	
	stdout, err := c.StdoutPipe()
	if err != nil {
		t.Fatal(err)
	}
	if err := c.Start(); err != nil {
		t.Fatal(err)
	}
	n, err := consumeSlow(stdout, 50000, 5 * time.Millisecond)
	if err != nil {
		t.Fatal(err)
	}
	
	expected := 2 * 1024 * 1000
	if n != expected {
		t.Fatalf("count mismatch: %d expected %d", n, expected)
	}
	
}

func consumeSlow(reader io.Reader, chunkSize int, interval time.Duration) (n int, err error) {
	buffer := make([]byte, chunkSize)
	for {
		var readBytes int
		readBytes, err = reader.Read(buffer)
		n += readBytes
		if err != nil {
			if err == io.EOF {
				err = nil
			}
			return
		}
		time.Sleep(interval)
	}
}