Merge lp:~nuclearbob/utah/no-virbr0-postinst-fix into lp:utah

[Max Brustkern]

If we install the utah package on a machine that has virbr0 configured as TAPBR by libvirt, but virbr0 is not actually up, the postinst will give a ValueError when trying to get through address through netifaces. This change wraps that in a try block and prints False in the case of a value error.

[Javier Collado (javier.collado)]

What about checking the interface before trying to access its data with something like:
if $TAPBR in netifaces.interfaces():
    print netifaces.AF_INET in netifaces.ifaddresses('$TAPBR')
else:
    print False

I don't like much catching exceptions for conditions that can be checked before accessing
some invalid value.

[Max Brustkern (nuclearbob)]

That seems reasonable to me. I'll update that and resubmit when it's ready.

[lp:~nuclearbob/utah/no-virbr0-postinst-fix]

721. By Nuclear Bob <max@daedelus> on 2012-10-31

Changed iface check based on Javier's suggestion

[Max Brustkern (nuclearbob)]

Updated the iface check.

review: Needs Resubmitting

[lp:~nuclearbob/utah/no-virbr0-postinst-fix]

722. By Nuclear Bob <max@daedelus> on 2012-10-31

Quoted $TAPBR properly

[Javier Collado (javier.collado)]

Looks nice now. Thanks.

review: Approve

=== modified file 'debian/utah.postinst'
--- debian/utah.postinst	2012-10-04 11:45:00 +0000
+++ debian/utah.postinst	2012-10-31 15:59:21 +0000
@@ -15,8 +15,16 @@
       function dnssetup
       {
         # Check that interface is up and has address assigned to it
-        interface_up=$(python -c "import netifaces; \
-            print netifaces.AF_INET in netifaces.ifaddresses('${TAPBR}')")
+        interface_up=$(python<<EOD
+import netifaces
+
+if '$TAPBR' in netifaces.interfaces():
+    print netifaces.AF_INET in netifaces.ifaddresses('$TAPBR')
+else:
+    print False
+
+EOD
+)
         if [ "${interface_up}" == "True" ]
         then
           # Get address assigned to the interface