[plt-scheme] Re: Using planet packages with the Handin server?

You can avoid some of the steps by making sure that the planet package
is installed before creating the sadnbox, I expect.

On Mon, Sep 21, 2009 at 4:52 PM, John Clements
<clements at brinckerhoff.org> wrote:
>
> On Apr 22, 2009, at 4:18 PM, Eli Barzilay wrote:
>
>> On Apr 22, John Clements wrote:
>>>
>>> My interpretation of this is that the sandbox *is* allowing access
>>> to the directory where the planet files live, but that trying to
>>> load the planet code also requires access to a number of other
>>> directories; that, to put it differently, the set of files loaded by
>>> the require statement is not the same as the set of directories that
>>> must be readable in order for planet to work correctly.
>>>
>>> Is this correct?
>>
>> That sounds right.  The thing is that the sandbox code does some
>> guessing of the paths that are needed, but it's not dealing with
>> planet paths.  Even if you allow reading all the paths that are
>> needed, you still need to:
>>
>> * allow writing to several places for planet to save stuff,
>>
>> * arrange a code inspector that will allow it to compile files,
>>
>> * somehow make it so no sandbox steps over another sandbox's file, for
>>  example, it's probably not a good idea to let several sandboxes
>>  copile the same files,
>>
>> * allow a network connection.
>>
>> The alternative would be to make sure that the files are already in,
>> that planet will not try to use the network or compile or write into
>> any file.  This might be doable, but I don't know the details.
>>
>> Perhaps you can get this in an easier way by requiring the planet
>> module from your own code, and use the namespace argument to share the
>> planet module's instance with the sanbox?
>
> Well, I'm coming back to this five months later, because PLAI is now a
> planet package, which means that my inability to refer to planet packages in
> the handin server now means that I can't make the handin server work with
> PLAI at all.
>
> Specifically, I'm hoping that you or someone else with additional
> namespace-fu can help me with the necessary plumbing to implement your
> suggestion.  Alternatively, since (IIRC) you are use PLAI yourself, perhaps
> you've already extended the handin server to work with planet packages in a
> way that's not already obvious to me.
>
> My attempts to "require the planet module from my own module and use the
> namespace argument to share the planet module's instance with the sandbox"
> thus far amount to something like this:
>
> #lang scheme
>
> (require scheme/sandbox)
>
>
> (namespace-require '(planet plai/plai))
> (namespace-attach-module (current-namespace)
>                         '(planet plai/plai))
>
>
> ((make-evaluator '(planet plai/plai) '(+ 3 4)
>                 #:allow-read '((planet plai/plai))) 13)
>
>
> My hope was that this would add the planet module-path to the current
> namespace in such a way that the make-evaluator call would refer to the
> existing one, and avoid the permissions problems.
>
> Unfortunately, the error is unchanged: I get
>
> directory-list: `read' access denied for /Users/clements/Library/PLT
> Scheme/planet/300/4.2.1/cache/plai/plai.plt
>
> Perhaps the solution is to somehow attach the planet module to the current
> namespace using a new identifier, and have the make-evaluator call refer to
> the new identifier.  However, I can't find a call in the namespace zone that
> would allow me to do this.
>
> The final "throw up my hands" solution is to un-planet-ize plai, and turn it
> into a regular collection. This seems fragile, but maybe it's the best way
> to go?
>
> Any help appreciated,
>
> John
>
>
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