Disables auto-upping due to `[ifupdown] managed=true` even if network-manager is not installed

[Thomas Hood]

If the network-manager package has been removed but not purged and /etc/NetworkManager/NetworkManager.conf contains

    [ifupdown]
    managed=true

then ifup still refrains from bringing up interfaces automatically.

This has already confused at least one person.

    http://askubuntu.com/questions/302840/etc-network-interfaces-ignored/304291

It might be better if ifup refrained from bringing up "auto" interfaces only if network-manager is installed.

[Robie Basak (racb)]

Are you sure that this is the case? This does not appear to be documented in the NetworkManager.conf manpage. By what mechanism does ifupdown refrain from touching these interfaces?

[Thomas Hood (jdthood)]

By this mechanism:

=== ifupdown.nw ===

<<main functions>>=
static int auto_disabled() {
       static int initialized = 0;
       static int auto_up_disabled = 0;

       if (!initialized) {
               dictionary *ini_dict;
               initialized = 1;

               ini_dict = iniparser_load (nm_system_settings);
               if (ini_dict) {
                       int managed = iniparser_getboolean (ini_dict, "ifupdown:managed", 0);
                       auto_up_disabled = managed ? 1 : 0;
                       iniparser_freedict (ini_dict);
                       ini_dict = 0;
               } else {
                       auto_up_disabled = 0;
               }
       }

       return auto_up_disabled;
}
@

[Robie Basak (racb)]

Thanks! Am I missing some documentation of this behaviour somewhere, or is it really only documented in the code and in a printed warning on execution? It seems to me that it is essential that this should be documented, because it's an interaction that one wouldn't expect. Is this a separate bug?

[Thomas Hood (jdthood)]

It was mentioned in the changelog.

ifupdown (0.6.8ubuntu10) intrepid; urgency=low
  https://lists.ubuntu.com/archives/ubuntu-devel/2008-October/026656.html:
  * stop ifupdown to auto-up/down interfaces if network-manager's
    ifupdown plugin is in managed=true mode
    [...]
 -- Alexander Sack <email address hidden> Thu, 09 Oct 2008 16:46:47 +0200

The feature should certainly be documented in interfaces(5) and/or ifup(8) too.

[Robie Basak (racb)]

Thanks Thomas. I've filed bug 1188169.