Re: [GIT PULL] kdbus for 4.1-rc1

Richard Weinberger
2015-04-29T14:59:13Z

Am 29.04.2015 um 16:53 schrieb Harald Hoyer:
> On 29.04.2015 16:18, Richard Weinberger wrote:
>> Am 29.04.2015 um 16:11 schrieb Harald Hoyer:
>>>>> We don't handcraft the initramfs script for every our customers, therefore we
>>>>> have to generically support hotplug, persistent device names, persistent
>>>>> interface names, network connectivity in the initramfs, user input handling for
>>>>> passwords, fonts, keyboard layouts, fips, fsck, repair tools for file systems,
>>>>> raid assembly, LVM assembly, multipath, crypto devices, live images, iSCSI,
>>>>> FCoE, all kinds of filesystems with their quirks, IBM z-series support, resume
>>>>> from hibernation, […]
>>>>
>>>> This is correct. But which of these tools/features depend on dbus?
>>>
>>> I would love to add dbus support to all of them and use it, so I can connect
>>> them all more easily. No need for them to invent their own version of IPC,
>>> which can only be used by their own tool set.
>>
>> Why/how do you need to connect them?
>> Sorry for being persistent but as I use most of these tools too (also in initramfs)
>> I'm very curious.
>>
>> Many of us grumpy kernel devs simply don't know all the use case of you have to cover.
>> So, please explain. :-)
>>
>
> Well, using shell scripts I connected all of these tools in the earlier
> versions of dracut [1]. Been there, done that.
>
> When using bash to wait for an interface to come up [2] or doing dhcp [3], the
> (at least my) pain threshold is reached, and you want something more sophisticated.
>
> So, one starts eyeing NetworkManager or systemd-networkd. Both of them have CLI
> tools and helpers and these tools and helpers talk to each other with (guess
> what?) an IPC mechanism, which happens to be DBUS (because it's the IPC of
> choice, if you don't want to reinvent the wheel).
>
> But let's not pinpoint that to network alone. Parsing output of tools with
> shell scripts is horrible, slow, fragile, error prone.

So, you want to replace bash by dbus?
I'll stop now with arguing.
Let's agree to disagree.

> Sure, I can write one binary to rule them all, pull out all the code from all
> tools I need, but for me an IPC mechanism sounds a lot better. And it should be
> _one_ common IPC mechanism and not a plethora of them. It should feel like an
> operating system and not like a bunch of thrown together software, which is
> glued together with some magic shell scripts.

This is how UNIX works. ;)

Thanks,
//richard