Re: Early feedback on Guix Home

[Andrew Tropin <andrew@trop.in>]

Ludovic Courtès <ludo@gnu.org> writes:

> Hi,
>
> Xinglu Chen <public@yoctocell.xyz> skribis:
>
>> On Wed, Jun 23 2021, Ludovic Courtès wrote:
>
> [...]
>
>>> Anyway, I backed up a bunch of files :-) and eventually gave it a try,
>>> just to notice that ‘guix home reconfigure’ was very careful about
>>> creating backups of any files it was going to overwrite, and it was also
>>> explicitly saying what it’s doing.  Perfect.
>>
>> Yeah, the output is pretty verbose, which is good if someone is just
>> getting started with it, but there should probably also be an option to
>> make it less verbose.
>
> Yes.  Also, we’ll have to make sure it’s internationalized.
>
>>> I see two possible improvements:
>>>
>>>   1. Make the manual very upfront about that: don’t be afraid, config
>>>      files are backed up at that location, etc.
>>
>> Yeah, the manual needs some more work, maybe we should add an ‘migrating
>> to Guix Home’ section?
>
> That’s a good idea.
>
>>>   2. Review ‘symlink-manager.scm’ and work on simplifying it to make it
>>>      easier to understand what’s going on.
>>>
>>> Second, the other thing that stopped me from getting started is the
>>> initial config.  How could I move from all my undisciplined dotfiles to
>>> the single explicit config?  Eventually, I found that starting with
>>> nothing but packages, ‘home-bash-service-type’, and
>>> ‘home-ssh-service-type’ was the most reasonable option to begin with.
>>>
>>> Unfortunately, even ‘home-ssh-service-type’ was difficult to handle: I
>>> have a long ‘.ssh/config’ file and I wasn’t going to turn that into
>>> ‘ssh-host’ lines by hand.
>>
>> There is a ‘home-generic-service’ procedure that allows one to install
>> packages in dump a file somewhere in their home directory.
>>
>>   (home-generic-service
>>    'ssh-config
>>    #:packages (list openssh)
>>    #:files `(("ssh/config"
>>               ,(local-file "/path/to/some/ssh/config"))))
>
> Neat.
>
>>> Possible actions:
>>>
>>>   1. Provide a ‘guix home init’ command (or similar) that creates an
>>>      initial Home config based on existing config.
>>
>> As Andrew mentioned, I recently added a ‘guix home import’ command, but
>> in only imports the installed user packages.  Creating configurations
>> for the packages would require a lot more work, unless we just read the
>> contents of ~/.bashrc and ~/.config/git/config and use
>> ‘home-generic-service’ and ‘plain-file’, instead of using
>> ‘home-bash-configuration’ and ‘home-git-configuration’.
>
> For SSH, generating something like:
>
>    (service home-ssh-service-type
>             (home-ssh-configuration
>              (toplevel-options
>               `((include . ,(local-file "ssh.conf"))))))
>
> should be doable.  But yeah, we’ll have to see on a case-by-case basis
> what can be achieved.
>
>>>   2. In some cases, such as OpenSSH, provide converters from the native
>>>      format to its Scheme equivalent (maybe?).
>>
>> That would require a lot of work; we would have to parse all sorts of
>> weird configuration formats, not to mention that the upstream
>> configuration format can change in the future.  It would be nice to
>> have, but I don’t think it should be a blocker for merging Guix Home.
>
> Agreed.
>
>>>   3. For each service, provide an escape hatch: a way for users to
>>>      provide a raw config file.  We do that for all or most of the Guix
>>>      System services, and it helps a lot when people are starting from
>>>      an existing config.
>>
>> Since we already have the ‘home-generic-service’ helper, I am not sure
>> if explicitly providing an escape hatch for every single service is
>> worth it.  I feel like the point is to use Scheme to configure things,
>> and not to just concatenate big opaque strings.  People who haven’t
>> re-written their configs in Scheme can always use
>> ‘home-generic-service’.  ‘home-generic-service’ is also useful if say
>> the user wants to configure Mpv, but there is no Mpv service in Guix
>> Home.
>
> Yeah, ‘home-generic-service’ helps a lot, I didn’t know about it.

Will mention it in the manual.

> Overall, I think what I’m saying is that we should offer a smooth and
> gradual transition for enthusiasts (like me!) who’re willing to switch
> but can’t just be expected to rewrite all their config at once.
>
>>> Possible action:
>>>
>>>   1. Change config records to accept file-like objects instead of
>>>      strings.  That way, users can choose to have snippets inlined (in a
>>>      ‘plain-file’ object) or separate (via ‘local-file’).  See for
>>>      example how ‘tor-configuration->torrc’ does it.
>>
>> Yeah, there is a ‘slurp-file-gexp’ procedure that let’s one read an
>> extenal file, but using existing APIs like ‘local-file’ is probably a
>> better idea.
>
> Yes, it feels more natural.  Also, ‘slurp-file-gexp’ returns a gexp (a
> code snippet), but as a user you don’t know where that snippet is going
> to be inserted; it may not work in some contexts.

Acually, the idea behind `slurp-file-gexp` is that you always know where
it will be inserted, because it will be inside the specific section of
the configuration.  Take a look at emacs home-service example:
https://git.sr.ht/~abcdw/rde/tree/master/item/gnu/home-services/emacs.scm#L91

I'll explain it in more details in the manual.

Correct me, if I missunderstood your point.