bug: 280123
title: dhcp3-server needs if-up.d/if-down.d scripts for better network-manager compatibility
date-reported: Wed, 08 Oct 2008 11:25:48 -0000
date-updated: Fri, 20 Jul 2012 06:40:10 -0000
reporter: Oliver Grawert (ogra)
duplicate-of: 
duplicates: 242020
attachments: 
 https://bugs.launchpad.net/bugs/280123/+attachment/383724/+files/dhcp3-server text/plain
patches: 
tags: 
subscribers: 
 Oliver Grawert (ogra)
 Jonathan Crockett (jcrockett)
 Zaki Manian (zmanian)

task: dhcp3 (Ubuntu)
status: Won't Fix
date-created: Wed, 08 Oct 2008 11:25:48 -0000
date-left-new: Tue, 06 Oct 2009 12:43:27 -0000
date-closed: Fri, 20 Jul 2012 06:40:09 -0000
reporter: Oliver Grawert (ogra)
importance: Undecided
component: main
assignee: 
milestone: 

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with network manager introducing a new mode to manage interfaces in
/etc/network/interfaces, dhcp3-server will fail to start up in case this
mode is enabled. dhcp3-server needs to start after network manager to
make sure a usable interface is up. Since NM can also dynamically handle
interfaces through ifupdown, also if-up.d/if-down.d scripts need to be
put in place.
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Author: Thierry Carrez (ttx)
Date: Wed, 08 Oct 2008 16:21:45 -0000
Message-Id: <20081008162146.29077.41580.malone@gangotri.canonical.com>

dhcp3-server already starts after NetworkManager, so I'll adjust the
title.
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Author: Thierry Carrez (ttx)
Date: Tue, 14 Oct 2008 09:48:35 -0000
Message-Id: <20081014094835.21131.14509.malone@palladium.canonical.com>

Proposed /etc/network/if-up.d/dhcp3-server

Would a ifup.d script like this work for you ?
It is based on the openssh-server one. Like for openssh-server, I don't thi=
nk an ifdown.d script is necessary, as dhcp3-server seems to cope with down=
ed interfaces quite happily.

Let me know if it sounds ok and I'll prepare a proper debdiff.
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Author: Thierry Carrez (ttx)
Date: Tue, 14 Oct 2008 12:36:04 -0000
Message-Id: <20081014123604.2504.11883.malone@gangotri.canonical.com>

Hm, after more analysis I'm no longer convinced that this is
appropriate.

In the openssh-server case, the if-up.d script just calls the initscript
reload action, which sends a SIGHUP to the process (if any). This
doesn't have any side-effects.

This is not the same for dhcp3-server. There is no reload action so we call=
 restart, which does stop/sleep 2/start.
* this is called when interfaces are brought up at boot time, resulting in =
boot delay
* "/etc/init.d/dhcp3-server start" is called after the if-up.d script alrea=
dy started dhcp3-server, which is confusing, to say the least
* it results in DHCP server not serving addresses for a small time every ti=
me an interface is brought up
* More unanticipated breakage potential

The correct way to do it would be to have :
- an ifup.d script that returns immediately if dhcp3-server isn't already s=
tarted, so that it doesn't affect the boot. However dhcp3-server doesn't re=
ally start a process if there are no interfaces available, so the resulting=
 ifup script would not start it if needed interfaces are later brought up..=
. defeating the whole point of this bug, I suppose
- a graceful restart feature in dhcp3-server so as to minimize those reload=
s impact

So my guess is that dhcp3-server isn't sufficiently smart to be
integrated into ifup/ifdown without dirty side-effects...
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Author: Ronald (rhp-dse)
Date: Sun, 17 May 2009 20:17:27 -0000
Message-Id: <20090517201727.25924.77278.malone@potassium.ubuntu.com>

Hi all,

In jaunty this still seems to be a problem.
On my machine dhcp is starting even before NetworkManager.

Any idea when this will be resolved correctly?

Ronald
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Author: Chuck Short (zulcss)
Date: Tue, 06 Oct 2009 12:43:26 -0000
Message-Id: <20091006124326.3970.6.malone@palladium.canonical.com>

Oliver,

Is this still a problem for you on karmic?

Regards
chuck
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Author: Antonio Rosales (arosales)
Date: Thu, 19 Jul 2012 15:18:08 -0000
Message-Id: <20120719151808.23955.87331.malone@chaenomeles.canonical.com>

@Oliver / @Chuck,

As there has been a bit of gap in the history of comments could you
confirm if this is still an issue we should pursue in Quantal?

-Thanks
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Author: Oliver Grawert (ogra)
Date: Thu, 19 Jul 2012 15:57:32 -0000
Message-Id: <20120719155732.22373.26846.malone@gac.canonical.com>

all relases this was discussed for are actually EOL and the issue of NM
touching /etc/network/interfaces has been fixed in network-manager
since. please close ...
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