From: ara.t.howard@...
Date: 2006-03-26T00:25:29+09:00
Subject: Re: drb over pipes

On Fri, 24 Mar 2006, Reto Schuettel wrote:


> I've appended an example which uses your library. It creates two pipes,
> forks, connects the pipes to the stdin/stdout of the child and then execs
> the ssh client. The same technique could also be used to communicate with a
> child (instead of a unix/tcp socket or a simple plain pipe). IMHO that's
> really nice, great work Jonathan!
>
> require 'drb'
> require 'fdsocket'
>
> ctprd, ctpwr = IO.pipe
> ptcrd, ptcwr = IO.pipe
>
> pid = fork
>
> unless pid
>  # child
>  ctprd.close
>  ptcwr.close
>
>  $stdin.reopen( ptcrd )
>  $stdout.reopen( ctpwr )
>
>  exec("ssh", "hostname", "./agent.rb")
>
>  exit # child shounld't reach this point
> end
>
> # parent
> ctpwr.close
> ptcrd.close
>
> fd_read =  ctprd.fileno
> fd_write = ptcwr.fileno
>
> # The URI to connect to
> SERVER_URI="drbfd://#{fd_read},#{fd_write}"
> DRb.start_service
>
> obj = DRbObject.new_with_uri(SERVER_URI)
>
> [...]

i think this will fail with calls that use 'yield' or that return
'DrbUndumped' objects because they will attempt to open a connection __from__
'hostname' to 'localhost'.

this doccument details this in the ssh section

   http://www.rubygarden.org/ruby?DrbTutorial

fyi.


-a
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