[bug#70542] [PATCH 0/4] Improve Shepherd service support for networked file systems

[Richard Sent]

Hi Guix!

This patch series aims to improve the experience when using Guix and Shepherd
to manage networked file systems.

Previously, operating-system file-system entries would all be started before
the symbol 'file-systems was provided, which many other Shepherd services
depend on. This meant that adding a networked file-system with (mount? #t)
would (depending on mount-can-fail?) either halt boot due to 'user-processes
(and thus 'networking) not being provisioned, or fail to mount, even though
Guix contained the code to sucessfully mount that file system.

Now, file system entries can specify arbitrary Shepherd symbols that other
services provision. When this is done, that specific file-system entry is not
mounted as part of providing 'file-systems.

I considered adding a (network?) flag to the file-system record instead, but
that wouldn't handle every case (say, if an Avahi .local address was used). So
instead I went with the more general approach.

Prior workarounds were verbose [1] and required creating a custom service
entry. This method allows for reusing code already present in (gnu
services base) and (gnu build file-systems).

I considered splitting CIFS support into its own patch, but since the support
is fairly meaningless without the preceding commits, I figured keeping it was
best.

This patch series resolves https://issues.guix.gnu.org/46563.

Richard Sent (4):
  file-systems: Add requirements field to file-systems
  services: base: Use requirements to delay some file-systems
  file-systems: Add support for mounting CIFS file systems
  system: Do not check for CIFS file system availability

 doc/guix.texi               | 13 ++++++++
 gnu/build/file-systems.scm  | 60 ++++++++++++++++++++++++++++++++-----
 gnu/machine/ssh.scm         |  3 +-
 gnu/services/base.scm       | 16 ++++++++--
 gnu/system/file-systems.scm |  3 ++
 guix/scripts/system.scm     |  3 +-
 6 files changed, 87 insertions(+), 11 deletions(-)


base-commit: 0f68306268773f0eaa4327e1f6fdcb39442e4a34
-- 
2.41.0