Ensure that we have access to sbin binaries through sudo

We need to add the sbin paths to the secure path in sudoers for the user
running the script, to make sure that running sbin binaries from sudo
will work.

Change-Id: I7942407df768bfa8dd035f15fa8b43ba05319779

stack.sh

@@ -193,6 +193,9 @@ else
     # Set up devstack sudoers
     TEMPFILE=`mktemp`
     echo "`whoami` ALL=(root) NOPASSWD:ALL" >$TEMPFILE
+    # Some binaries might be under /sbin or /usr/sbin, so make sure sudo will
+    # see them by forcing PATH
+    echo "Defaults:`whoami` secure_path=/sbin:/usr/sbin:/usr/bin:/bin:/usr/local/sbin:/usr/local/bin" >> $TEMPFILE
     chmod 0440 $TEMPFILE
     sudo chown root:root $TEMPFILE
     sudo mv $TEMPFILE /etc/sudoers.d/50_stack_sh