[bug#29467] [PATCH] web: Don't error about missing ssl related files.

[ludo@gnu.org (Ludovic Courtès)]

Hi,

julien lepiller <julien@lepiller.eu> skribis:

> Le 2017-11-27 09:26, Christopher Baines a écrit :
>> Erroring here prevents doing things like building a system using
>> nginx on a
>> different machine from where it's intended to be deployed, or creating
>> containers and VMs that use the ssl-certificate parts of the nginx
>> configuration, without also getting these files to exist.
>>
>> * gnu/services/web.scm (emit-nginx-server-config): Don't error on
>> missing ssl
>>   related files.
>> ---
>>  gnu/services/web.scm | 10 ----------
>>  1 file changed, 10 deletions(-)
>>
>> diff --git a/gnu/services/web.scm b/gnu/services/web.scm
>> index 9d713003c..1af32278c 100644
>> --- a/gnu/services/web.scm
>> +++ b/gnu/services/web.scm
>> @@ -191,16 +191,6 @@ of index files."
>>              (syntax-parameterize ((<> (identifier-syntax x*)))
>>                (list tail ...))
>>              '())))
>> -    (for-each
>> -     (match-lambda
>> -      ((record-key . file)
>> -       (if (and file (not (file-exists? file)))

There’s another problem: ‘file-exists?’ checks the current machine,
under the current root file system.  That check doesn’t work if you do
“guix system init config.scm /some/other/root”, or if you create a
container, or with the envisioned “guix system reconfigure --remote”.

> Hi, when configuring nginx for the first time, users will probably
> forget to
> configure ssl properly. The default is to enable ssl and find
> certificates in
> /etc/nginx. When these files don't exist, nginx will fail to start and
> at least
> one user complained it was hard to debug. This code was introduced to
> prevent
> such a mistake.

Yes, I agree that it’s nice to have early error reports.

> Maybe we should set the default to #f (but then users would have to
> configure
> more fields to enable https). Maybe we should add a configuration
> option like
> warn-only? (default to #f) to only warn about missing files. Or maybe
> there's
> a way to show nginx that another service is providing that file?

Good questions.

We cannot check for file existence at configuration time for the reasons
above.

We cannot check for file existence at build time because certificates
may be part of the machine’s state; they are typically managed in a
stateful fashion, outside of GuixSD.

So the only option we’re left with is checking at run time, when we
start the service.  But that’s something nginx already does, I think?

As for the default, I would be in favor of setting it to #f, because I
can’t really think of a default that would work for everyone.

WDYT?

Ludo’.