Hello Victor, 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 have been working on a tool called image-bootstrap [4] for a while, >> originally aimed at creating virtual machine images for Debian and >> Ubuntu. Recently, I have added Arch Linux support to image-bootstrap >> (and created an Arch equivalent of Debian's debootstrap [5] called >> "directory-bootstrap" in the process, same code base). > > There is pacstrap utility. I think it is official equivalent of > debootstrap AND it is maintained by Arch developers. directory-bootstrap is actually using pacstrap internally. While debootstrap can be used on a non-Debian flavor of Linux, pacstrap seems to require that Arch chroot that [9] is teaching users to build. directory-bootstrap is like a wrapper around pacstrap making it work from non-Arch distributions. >> To give access to the full disk space to users, OpenStack images are >> prepared to do the following: >> >> 1. During early boot (initramfs time), the one and only partition is >> enlarged to the full size of the disk. >> >> 2. during normal boot, cloud-init is running resize2fs to enlarge >> the ext4 root file system to the new size of that partition. >> >> It's a little crazy, but it works: the user hardly notices. >> >> 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. > There is also mkinitcpio-growrootfs > (https://aur.archlinux.org/packages/mkinitcpio-growrootfs/). It's > probably what you were looking for but it looks like package is not > supported by its developer anymore. So you probably shouldn't use this > mkinitcpio hook. Just what I was looking for, excellent pointer. It seems there are two more alive forks of that: * https://github.com/aryklein/mkinitcpio-growrootfs/ * http://git.uplinklabs.net/snoonan/projects/archlinux/ec2/ec2-packages.git/tree/mkinitcpio-growrootfs I still need to have a closer look at those. I would love to see something like that in the master repository of Arch. > 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. >> 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. >> [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. Best, Sebastian
