From a9672bd5afd962f33f869b7cdb333c8cb70060f4 Mon Sep 17 00:00:00 2001
From: Pagan Gazzard <pjgazzard@googlemail.com>
Date: Tue, 19 Aug 2014 18:09:19 +0100
Subject: [PATCH] Make sure that the command socket exists and is a socket.

This handles the case of running an updated supervisor on an old image which doesn't support host commands - printing out a nice message and waiting rather than exiting silently.
---
 src/enterContainer.sh | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/src/enterContainer.sh b/src/enterContainer.sh
index 98bd19a8..a3301e50 100644
--- a/src/enterContainer.sh
+++ b/src/enterContainer.sh
@@ -3,10 +3,16 @@ SOCKET_NAME=test-${1}-${2}-${3}
 HOST_DATA_PATH=/resin-data/resin-supervisor
 HOST_SOCKET=${HOST_DATA_PATH}/${SOCKET_NAME}
 SUPERVISOR_SOCKET_PATH=/data
+COMMAND_SOCKET=${SUPERVISOR_SOCKET_PATH}/host
 
-echo "
-	rm -f ${HOST_SOCKET}
-	socat UNIX-LISTEN:${HOST_SOCKET} EXEC:'${HOST_DATA_PATH}/enter.sh ${1}',pty,setsid,setpgid,stderr,ctty &
-	exit
-" | socat UNIX:${SUPERVISOR_SOCKET_PATH}/host - >& /dev/null
-socat UNIX:${SUPERVISOR_SOCKET_PATH}/${SOCKET_NAME} -,raw,echo=0
+if [ ! -S ${COMMAND_SOCKET} ]; then
+	echo 'TTY mode not supported on this image, please update.'
+	sleep infinity
+else
+        echo "
+                rm -f ${HOST_SOCKET}
+                socat UNIX-LISTEN:${HOST_SOCKET} EXEC:'${HOST_DATA_PATH}/enter.sh ${1}',pty,setsid,setpgid,stderr,ctty &
+                exit
+        " | socat UNIX:${COMMAND_SOCKET} - >& /dev/null
+        socat UNIX:${SUPERVISOR_SOCKET_PATH}/${SOCKET_NAME} -,raw,echo=0
+fi