Interview with NetworkManager developer Dan Williams [LWN.net]

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 8:01 UTC (Tue) by crackmonkey (guest, #31592) [Link] (13 responses)

I'm disappointed that he does not address one of the fatal design flaws of networkmanager:
namely that it uses gconf as a datastore in spite of all the ways in which gconf was
deliberately cut to make that a bad idea.

gconf is a *configuration* storage and query system, and yet NM stores seen wireless networks
in it without any sort of schema.  Ever try to delete a bogus entry from gconf?  It'll be back
in a few hours!  Sometimes the only way to fix it is to blow away your local gconf database
entirely and rebuild from the ground up.  Thanks a bunch, Dan.

Please oh please couldn't you at *least* have resorted to a bdb or sqlite or some other local
storage?  Why did you have to decide that gconf needed to be abused like the Windows Registry?

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 9:01 UTC (Tue) by mbottrell (guest, #43008) [Link] (3 responses)

I've personally dropped NetWork Manager where I need Wireless/WPA2.
I found it very unstable, to the point I had to restart networking every 10 minutes.

Gone back to traditional configs in flat files.. and bring up the wireless via an init script.
It's been flawless since.

I would prefer NW used flatfiles that are easily editable via a CLI.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 12:43 UTC (Tue) by richo123 (guest, #24309) [Link]

Try wicd instead then.

http://wicd.sourceforge.net/

The beauty of open source is choice ;-)

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 14:31 UTC (Tue) by dcbw (guest, #50562) [Link]

0.7 has the ability (turned on in Fedora) to read configuration from
/etc/sysconfig/networking/profiles/<name>/ifcfg-* and use those as "system" connections that
override the ones in GConf.  They look and work just like normal connections, but may be used
to lock down network config of the machine as well.  They also provide the ability to bring up
the network before login.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 15:26 UTC (Tue) by drag (guest, #31333) [Link]

> I've personally dropped NetWork Manager where I need Wireless/WPA2.
I found it very unstable, to the point I had to restart networking every 10 minutes.

Newer versions are much better then older versions. I don't know were the cut-off point was.
With the old stuff I totally abandoned it and went with the Debian-style configuration and
wpasupplicant, which was very good. But there was a big version change that pretty much solved
every issue I had with it, mostly except...



> I would prefer NW used flatfiles that are easily editable via a CLI.


OH YES FFS!

Configuration files are a godsend. Nobody has any business making any sort of serious utility
or tool that can not be configured by a text editor. It's just criminal to do anything else.  

:)

bug report?

Posted Feb 26, 2008 12:15 UTC (Tue) by pjm (guest, #2080) [Link]

It would be helpful if you could give a link to the entry in the bug tracker for this, so that
readers can follow its progress and perhaps help towards its resolution.  If there isn't an
entry in the bug tracker, then please create one (minus the sarcasm, I suggest) before idly
flaming in an unrelated forum.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 12:57 UTC (Tue) by Frej (guest, #4165) [Link] (5 responses)

Does this cause a problem as user or as an administrator?
Or
When does the backend cause a problem for you?

Not intended as flamebait.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 15:17 UTC (Tue) by mattdm (subscriber, #18) [Link] (4 responses)

As a user. But the backend is only incidental to the problem, which is that in the current
(pre 1.0, note) implementation, there's no user interface for editing known connections, so
your only recourse is to dive into gconf-editor.

When there is a good control interface, it won't matter how to users awkward the backend is
for the job.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 15:32 UTC (Tue) by Frej (guest, #4165) [Link] (2 responses)

I agree that storing state in gconf is wrong/suboptimal ;)
But I personally haven't had the need for editing stored connections.
When would this be needed?

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 16:49 UTC (Tue) by mattdm (subscriber, #18) [Link] (1 responses)

What if you don't want a given connection to try to autoconnect?

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 17:01 UTC (Tue) by dcbw (guest, #50562) [Link]

bclark and I have played with adding a button to the notification bubbles when you're
connected to say things like "don't automatically connect me ever again" and such.  I think
there's a lot of room to use the notification bubbles more to save users clicks rather than
having to run to the connection editor in the right-click menu.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 16:30 UTC (Tue) by dcbw (guest, #50562) [Link]

Both 0.7 and 0.6.6 (to be released in a week or two) include a GUI connection editor that
allows you to delete connections stored in GConf.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 14:36 UTC (Tue) by dcbw (guest, #50562) [Link] (1 responses)

I'd expect your issues aren't with GConf as a storage system per se.  It's a fine place to
store configuration and quite a few apps do it.  NetworkManager can also pull configuration
information from text files in /etc.

The absence of GConf schema is something we can quite easily rectify in 0.7 since the
configuration format is well-defined there.  I'm curious though; in what ways would having a
GConf schema make things work more smoothly for you?

If you delete an network from GConf, NetworkManager will _never_ autoconnect to that network
again, until you tell it to explicitly from the NM menu.  Any behavior other than that is a
bug.  If you've picked the network from the menu before, that network is fair game for NM.

Both 0.6.x and 0.7 include connection editors that allow you to easily delete saved networks
too.

Editing gconf

Posted Feb 26, 2008 17:06 UTC (Tue) by BrucePerens (guest, #2510) [Link]

I think he wants a schema so that he can use XML tools to edit the GConf database. He should probably be talking to gconfd instead, however we all like using text files the way they were intended to be modified on Unix, with an editor. Perhaps gconf should detect this using fstat, etc. In general modifying a gconf entry with an editor means you kill gconfd and the application that you are configuring, edit, and restart gconfd and the application. I went through this recently when some spurious gconf data caused my laptop keyboard to be repeatedly locked in NUM-shift, which made it impossible to even use the shell from X, I had to use a console terminal interface to recover from this.

Bruce

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 17:50 UTC (Tue) by chaneau (guest, #6674) [Link] (2 responses)

I recently had to configure my network interface with a bridge, so now the applet tells me that I have no network connection at all

As posting this comment shown this is not totally correct ;-)

Here is my /etc/network/interfaces, you would believe that such a simple case would be covered, but apparently it is not.

auto br0

iface br0 inet dhcp
    bridge_ports eth0

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 22:42 UTC (Tue) by cortana (subscriber, #24596) [Link] (1 responses)

Debian alters NM so that if an interface is mentioned in /etc/network/interfaces, NM ignores
it completely, except for when it's a simple 'iface foo inet dhcp' entry.

See /usr/share/doc/network-manager/README.Debian for more information.

Interview with NetworkManager developer Dan Williams

Posted Feb 27, 2008 7:13 UTC (Wed) by chaneau (guest, #6674) [Link]

Thanks for the info, I did not know that.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 18:12 UTC (Tue) by mwalls (guest, #6268) [Link] (3 responses)

I have just finished ripping NetworkManager out of FC8 on my notebook 
(replacing it with knemo, wlassistant, & sudo).  I can point out a couple 
mistaken design assumptions:

a) wireless network with same SSID's are not necessarily the same network 
(grrrr, linksys).
b) doesn't handle interfaces that power up/down & disappear/reappear well 
(ipw3945).
c) autoconnect can't be disable for a device (not profiles, the whole
device).

Nice idea, but I'll check back in a year.

Interview with NetworkManager developer Dan Williams

Posted Feb 27, 2008 3:20 UTC (Wed) by jamesh (guest, #1159) [Link] (1 responses)

hasn't NetworkManager included a blacklist for common "default" SSIDs for a long time?

Interview with NetworkManager developer Dan Williams

Posted Feb 27, 2008 4:49 UTC (Wed) by bronson (subscriber, #4806) [Link]

I hope not!  That's certainly not an acceptable fix for the problem.

Interview with NetworkManager developer Dan Williams

Posted Feb 28, 2008 14:57 UTC (Thu) by BenHutchings (subscriber, #37955) [Link]

"a) wireless network with same SSID's are not necessarily the same network 
(grrrr, linksys)."

True, but if it distinguished networks by the AP's BSSID (MAC address) then it wouldn't work
properly with multi-cell networks, which are exactly what ESSID enables. Interestingly, if you
disable ESSID broadcasts then it can recognise the network by BSSID. So it might not be too
hard to add the option to recognise other networks that way too.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 18:32 UTC (Tue) by jwb (guest, #15467) [Link] (2 responses)

I too have found Network Manager to be deeply flawed.  I have excised it from my Ubuntu
laptop.  It can prevent the machine from shutting down or sleeping, which is quite annoying,
and it drains battery power.  With my Atheros hardware Network Manager is incapable of joining
or forming an Ad-Hoc network, although it claims success when instructed to do so.  And it's
tendency to join a network with the same name but different BSSID is annoying and possibly
insecure.

Good idea, bad implementation.

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 18:54 UTC (Tue) by salimma (subscriber, #34460) [Link] (1 responses)

Funny, on OS X the problem is in the other direction: it keeps asking whether it should join a
network I have joined before (my wireless router)

Interview with NetworkManager developer Dan Williams

Posted Feb 26, 2008 18:55 UTC (Tue) by salimma (subscriber, #34460) [Link]

Clarification: I meant OS X's wireless subsystem, not NM. NetworkManager (as is currently in
Rawhide) feels much more polished than the version in F-8, which was already quite good