Re: [PATCH 2/2] scripts: Add 'publish' command.

[ludo@gnu.org (Ludovic Courtès)]

David Thompson <dthompson2@worcester.edu> skribis:

> Mark H Weaver <mhw@netris.org> writes:
>
>> ludo@gnu.org (Ludovic Courtès) writes:
>>
>>> David Thompson <dthompson2@worcester.edu> skribis:
>>>
>>>> +(define (render-nar request store-item)
>>>> +  "Render archive of the store path corresponding to STORE-ITEM."
>>>> +  (let ((store-path (string-append %store-directory "/" store-item)))
>>>> +    ;; The ISO-8859-1 charset *must* be used otherwise HTTP clients will
>>>> +    ;; interpret the byte stream as UTF-8 and arbitrarily change invalid byte
>>>> +    ;; sequences.
>>>> +    (if (file-exists? store-path)
>>>> +        (values '((content-type . (application/x-nix-archive
>>>> +                                   (charset . "ISO-8859-1"))))
>>>> +                (lambda (port)
>>>> +                  (write-file store-path port)))
>>>> +        (not-found request))))
>>>
>>> This is OK for now, but I just realized that this will be blocking the
>>> server for the duration of the whole transfer.  Someone could DoS you by
>>> substituting TeX Live.  ;-)
>>>
>>> We’ll need a solution but it seems that it’ll be hard to avoid threads.
>>>
>>> Thoughts?
>>
>> I haven't looked closely, but how about using subprocesses instead of
>> threads?

Sounds good.

> That's along the lines of what I was thinking.  One could spawn a bunch
> of 'guix publish' processes on different ports and put a load balancer
> in front of them.

What about changing the ‘open’ method of the <server-impl> (as in
tests/lint.scm) so that it forks upon socket opening?  (That could also
be the moment where we’d drop privileges.)

> I think that this problem, if it is to be solved with more Scheme code,
> is an issue to address in Guile core by changing the http server
> implementation.

Once we have a sufficiently different and valuable server
implementation, we could turn it into a (web server xxx) module.  I
think there’s value in keeping the simple/simplistic (web server http)
too.

Ludo’.