[arch-general] Generating Arch OpenStack images

[Victor Dmitriyev]

Hello.

On 23.06.2015 04:57, Sebastian Pipping wrote:
> On 21.06.2015 12:50, Victor Dmitriyev wrote:
>> Arch is highly configurable so it's assumed that you build a system for
>> your needs by yourself.
>
> in general: yes.  However, the requirements on OpenStack images [6] are
> rather strict, e.g. a single partition with an ext3/4 file system and
> using cloud-init.  So the base would be the same for any OpenStack image
> playing by the rules.  You could build that base manually, or you could
> use a tool and do that (with HTTP caching) in about 90 seconds.  With
> that minimal base, you can still configure the system to your very
> needs.  I think it's no different to Debian or Gentoo, in that regard.

I guess it's alright, you should probably file a feature request on 
bugtracker then.

>>> In Debian, apart from cloud-init that magic is done by packages
>>> cloud-utils and cloud-initramfs-growroot of cloud-initramfs-tools [7].
>>> While Arch does have cloud-init, I find cloud-utils in AUR only and no
>>> cloud-initramfs-growroot at all.
>>
>> It seems that cloud-init can perform this task by itself
>> (https://wiki.archlinux.org/index.php/Cloud-init#Other_sections_in_cloud.cfg).
>
> cloud-init is calling resize2fs (if configured to do so) but it cannot
> grow the partition.  That has to be done in the initramfs before
> mounting.  So cloud-init relies on an enlarged partition to do the
> resize2fs work.  However, unlike with Debian, mkinitcpio-growrootfs is
> calling resize2fs itself already so cloud-init does not seem to have
> much to resize any more in Arch.

The cloud-init package has growpart module which apparently can resize 
partitions. It uses gpart utility which is in official repositories or 
growroot utility which is part of cloud-utils package [10]. Try it out. 
It might actually be sufficient.

>> The cloud-utils package right now is in official repositories
>> (https://www.archlinux.org/packages/community/any/cloud-init/), how you
>> missed that?
>
> I wrote "[w]hile Arch does have cloud-init".  I didn't miss it.

Sorry, I've mistaken cloud-utils for cloud-init in this line:
 >>> While Arch does have cloud-init, I find cloud-utils in AUR only and no

>>> There is yet something else: Trust.  Anyone can make images and upload
>>> them but who is going to trust the image if it is not signed by a person
>>> that they trust?
>>> There is a group of five people in the Arch master signing keys [8].
>>> One of them created, signed and uploaded the
>>> archlinux-bootstrap-*.tar.gz files that users rely on.  My hope is that
>>> one of these five is willing to use image-bootstrap [4] to create, sign
>>> and upload OpenStack images as well.
>>
>> archlinux-bootstrap-*.tar.gz files are meant for installation of
>> Archlinux from a computer running another Linux distribution
>> (https://wiki.archlinux.org/index.php/Install_from_existing_Linux#Method_B:_Using_the_Bootstrap_Image_.28recommended.29),
>> so, of course, Arch developers sign this installation medium.
>
> I'm very happy that they do.
>
>
>> In my opinion, official Arch OpenStack images is pointless because what
>> point in server image that you need to configure anyway?
>
> Creating an OpenStack images manually takes debugging and time to figure
> things out.  That alone may be a reason why some people would either use
> something ready to use or to save the trouble altogether.  I don't see
> why people would want OpenStack images for Debian, Ubuntu, CentOS,
> Fedora, Gentoo, but not Arch Linux.

Yeah, probably.

Anyway, if you will successfully create OpenStack image I hope you will 
share your experience on ArchWiki somewhere.

>>> [6]
>>> http://docs.openstack.org/image-guide/content/ch_openstack_images.html
>
> [9]
> https://wiki.archlinux.org/index.php/Install_from_existing_Linux#Creating_the_chroot
>
>
>> In conclusion, I have an impression that you miss the point of Arch, so
>> I point you towards the ArchWiki again:
>> Arch Linux -- https://wiki.archlinux.org/index.php/Arch_Linux
>> The Arch Way -- https://wiki.archlinux.org/index.php/The_Arch_Way
>> Installation guide --
>> https://wiki.archlinux.org/index.php/Installation_guide
>> cloud-init -- https://wiki.archlinux.org/index.php/Cloud-init
>> and, in general, the ArchWiki has a lot of useful information.
>
> Which point of Arch did I miss?
> I'm aware about its rolling release nature and that some people may want
> to avoid rolling release distros in a cloud or any server context.  Some
> do and some don't.

I overreacted. For some reason I thought that tone of your mail was a 
bit bossy.

In the end, I hope you will create a basement of the official way to use 
Arch on OpenStack.

Regards,
Victor

[10] 
http://bazaar.launchpad.net/~cloud-init-dev/cloud-init/trunk/view/head:/cloudinit/config/cc_growpart.py#L117