Re: [tlug] [CFP] Call for presenters - May 10 Technical Meeting

[Travis Cardwell <travis.cardwell@example.com>]

On 2014年04月24日 16:36, Kalin KOZHUHAROV wrote:
> On Thu, Apr 24, 2014 at 3:13 PM, 黒鉄章 wrote:
> > If only there was some way to make virtual server instances that could be
> > set with identical filesystem snapshots and spun up in seconds, each with
> > their own IP addresses so any number of challengers could login and begin
> > instantaneously ....
> There are such solutions, but why bother?

It depends on the exercises; ephemeral containers / virtual machines might 
be desired if doing privilege escalation, destructive modification of the 
filesystem, etc.  Reading what you wrote below, I realize that you have a 
different sort of "capture the flag" in mind. :)

> A simple linux set up with remote ssh is enough.
> Everyone gets a home directory, nobody can sniff what others are doing
> (and there is no time). If you want more, namespace separation (to
> disallow people spoofing the options used for grep) or LXC is in
> order.
>
> Tasks are given by copying a certain directory, submitted by producing
> a file in ~/answer.txt ( a loop watches all ~/answer and greps for the
> right answer).
> Alternatively setup a git repo, clone in a new branch, commit/push
> back, add a server hook to look for correct answer and play a
> "BANG.wav". (branch is needed to prevent people from having unresolved
> conflicts).

This sounds like fun!  How about setting the server up to give users 
access to a sequence of challenges, one at a time?  When a user completes 
a challenge, the server can update a leaderboard webpage, announce it 
using TTS (example: "Kalin has completed challenge number one!"), and copy 
the next challenge into the user's directory.

Cheers,

Travis