Re: Network Manager does not find system wide connections

[Dan Williams <dcbw redhat com>]

On Wed, 2009-08-05 at 19:46 +0200, Hadmut Danisch wrote:
> Dan Williams wrote:
> >
> >
> > There are two reasons I've not yet added pre-up and pre-down.  They are:
> >
> >   
> 
> Whatever reasons there might be to have or not to have a pre-up and pre-down
> phase:
> 
> Omitting them in a single tool is simply the wrong place.
> 
> Many packets for debian/ubuntu  are designed for the four phases of
> the ifup/down system of debian for pretty good reasons.

It depends; reasons change, and so do implementations.  Nothing is set
in stone.

> If someone believes that this is wrong, then it should be discussed in
> general
> and not just omitted randomly by a single tool breaking the distribution
> policy.
> 
> I am fully aware that network manager has never been designed for
> debian/ubuntu,
> and is a redhat tool (although I am astonished that these good reasons

Completely wrong.  NetworkManager is *NOT* a Red Hat tool.  Novell has
contributed immensely to it, as have quite a few others from other
distributions.  It just happens that I am paid by Red Hat to spend 110%
of my time working on NetworkManager.

Nobody else has made that commitment.  If some other company or person
decided to invest time in NetworkManager, then that person or companies
goals would also obviously be reflected in the feature set of the final
product.

> should not apply
> to any distribution, e.g. security reasons).
> 
> I do not see any reason why NetworkManager should not call external
> pre-up and pre-down
> commands/scripts. It is the admin's or package maintainers problem if
> this script does not
> work properly. Leave it empty if you want.

It is not simply the admins and packagers problem.  It's also the user's
problem.

> However, if NetworkManager is strictly designed to not support more than
> two phases, then
> it might fit into RedHat, but not into the four phases-system of debian
> and ubuntu. Then it
> is simply the wrong tool for these distributions and the wrong decision
> to choose it.

So lets add some cold hard facts to the discussion.  What things are
people doing in pre-down scripts?

> Beyond the dispute whether two or four phases should be supported,
> Network Manager
> does not pass the required Information to the up/down scripts.

See below.  What other information do you need?  Is there some reason
the tools you're running in these phases cannot use D-Bus for network
even notifications if they are already running as a service somewhere?
If they are not running as a service, then yes, a one-shot script-based
approach may be more appropriate.

> Expecting the scripts to retrieve details with a given UUID over dbus is
> error prone and
> bad design, and it does not make the script run any faster.

The UUID is already passed to the scripts, and has been for a long time.
As are all the IPv4 details, and the DHCPv4 lease details if any.  What
version of NM are you using?

> I still believe that Network Manager is based on too many design
> mistakes requires
> a severe redesign and improved programming style (or replacement for
> ubuntu).

Tools before NetworkManager didn't work for a more dynamic environment
(especially wifi), thus we created NetworkManager.  I certainly don't
want a pile of shell glued together with duct-tape and chewing-gum,
which is what most of the previous networking system were.  I've written
about that extensively in various places.

That said, I'm perfectly willing to have a discussion about the merits
or shortcomings of NetworkManager, and what we are already doing to
improve it.

Dan