Re: Could libguestfs use springfield?

["Vojtěch Trefný" <vtrefny@redhat.com>]

On 06/14/2018 01:15 PM, Richard W.M. Jones wrote:
> 
> libguestfs provides a C library and large set of tools for
> manipulating disk images.  http://libguestfs.org/
> 
> As part of this we provide APIs to open VM disks and do things like
> enumerate partitions or resize logical volumes.  The actual way this
> works currently is we run the external commands (eg. parted, lvresize)
> inside a small virtual machine and pass the right command line options
> or parse the output.  In some cases we're also parsing stuff out of
> kernel /sys/block.
> 
> We've accumulated a large amount of code to do this (I counted 60619
> lines of code in the current version).  Here are a few examples so you
> can see in concrete terms what I'm talking about:
> 
> https://github.com/libguestfs/libguestfs/blob/afd1c70601c51043684a0245ce2f63d71a9cc07a/daemon/parted.c#L344
> 
> https://github.com/libguestfs/libguestfs/blob/afd1c70601c51043684a0245ce2f63d71a9cc07a/daemon/lvm.c#L271
> 
> Steven W pointed me to "Project Springfield" and it sort of looks like
> it's in the same area.  Could libguestfs replace the parsing code
> above with this?
> 
> What might be problems: We have no python or dbus in the appliance.
> So anything that depends on those is a non-starter.
> 
> TBH the project webpage left me more confused than enlightened.  There
> seem to be lots of projects (subprojects?) doing stuff with odd names
> and no unifying philosophy, and I'm not sure if Project Springfield is
> a thing or more of an intention.
> 
> Rich.
> 

Hi, project springfield is a collection of existing projects, 
libblockdev is probably the "subproject" you are looking for. It is a 
plugin based C library -- we have plugins for working with btrfs, 
filesystems (ext, xfs, vfat and ntfs), lvm, mdraid, partitions etc.
It mostly also uses the command line tools and in some cases also other 
existing libraries (libcryptsetup, libmount, libparted...).

Libblockdev Github repo: https://github.com/storaged-project/libblockdev
and API documentation: http://storaged.org/libblockdev/

 From the code you sent it looks like libblockdev covers most of the 
functionality libguestfs needs. Some functionality is missing (e.g. we 
don't support changing of uuid for lvs) but we can add these missing bits.

--
Vojtech Trefny