make stdin read from /dev/null for all cloud-init programs (LP: #903993)

the cloud-init programs are never intended to run interactively.
Some programs were being run via subprocess, and would notice that their
input was attached to a terminal (/dev/console).   As a result, they
they would try to prompt the user for input (apt-add-repository)

This change simply re-opens standard input as /dev/null so any
subprocesses will not end up blocking on input.

1 files changed, 2 insertions, 0 deletions

diff --git a/cloud-init.py b/cloud-init.py
index c38512fe..bc673265 100755
--- a/cloud-init.py
+++ b/cloud-init.py
@@ -34,6 +34,8 @@ def warn(wstr):
     sys.stderr.write("WARN:%s" % wstr)
 
 def main():
+    util.close_stdin()
+
     cmds = ( "start", "start-local" )
     deps = { "start" : ( ds.DEP_FILESYSTEM, ds.DEP_NETWORK ),
              "start-local" : ( ds.DEP_FILESYSTEM, ) }