1 files changed, 24 insertions, 22 deletions
diff --git a/contrib/python/podman/libs/_containers_attach.py b/contrib/python/podman/libs/_containers_attach.py
index 54e6a009e..bd73542b9 100644
--- a/contrib/python/podman/libs/_containers_attach.py
+++ b/contrib/python/podman/libs/_containers_attach.py
@@ -21,6 +21,9 @@ class Mixin:
 
         stderr is ignored.
         """
+        if not self.containerrunning:
+            raise Exception('you can only attach to running containers')
+
         if stdin is None:
             stdin = sys.stdin.fileno()
 
@@ -48,7 +51,7 @@ class Mixin:
             packed = fcntl.ioctl(stdout, termios.TIOCGWINSZ,
                                  struct.pack('HHHH', 0, 0, 0, 0))
             rows, cols, _, _ = struct.unpack('HHHH', packed)
-
+            # TODO: Need some kind of timeout in case pipe is blocked
             with open(ctl_socket, 'w') as skt:
                 # send conmon window resize message
                 skt.write('1 {} {}\n'.format(rows, cols))
@@ -73,38 +76,37 @@ class Mixin:
             # catch any resizing events and send the resize info
             # to the control fifo "socket"
             signal.signal(signal.SIGWINCH, resize_handler)
+
         except termios.error:
             original_attr = None
 
         try:
-            # Prepare socket for communicating with conmon/container
+            # TODO: socket.SOCK_SEQPACKET may not be supported in Windows
             with socket.socket(socket.AF_UNIX, socket.SOCK_SEQPACKET) as skt:
+                # Prepare socket for communicating with conmon/container
                 skt.connect(io_socket)
                 skt.sendall(b'\n')
 
                 sources = [skt, stdin]
                 while sources:
                     readable, _, _ = select.select(sources, [], [])
-                    for r in readable:
-                        if r is skt:
-                            data = r.recv(CONMON_BUFSZ)
-                            if not data:
-                                sources.remove(skt)
-
-                            # Remove source marker when writing
-                            os.write(stdout, data[1:])
-                        elif r is stdin:
-                            data = os.read(stdin, CONMON_BUFSZ)
-                            if not data:
-                                sources.remove(stdin)
-
-                            skt.sendall(data)
-
-                            if eot in data:
-                                sources.clear()
-                                break
-                        else:
-                            raise ValueError('Unknown source in select')
+                    if skt in readable:
+                        data = skt.recv(CONMON_BUFSZ)
+                        if not data:
+                            sources.remove(skt)
+
+                        # Remove source marker when writing
+                        os.write(stdout, data[1:])
+
+                    if stdin in readable:
+                        data = os.read(stdin, CONMON_BUFSZ)
+                        if not data:
+                            sources.remove(stdin)
+
+                        skt.sendall(data)
+
+                        if eot in data:
+                            sources.clear()
         finally:
             if original_attr:
                 termios.tcsetattr(stdout, termios.TCSADRAIN, original_attr)