CAF::Process supports shell option

[stdweird]

currently, CAF::Process support the LC::Process shell option (ie assume there's only one element in the command list, and run it as is (incl lack of protection again shell-isms).
we should eitehr document it or remove it. i'm in favour of removing it, but it goes against the 'should allow to shoot yourself in the foot' principle (also known as CAF devs shouldn't pretend to know it all 😉)

[jouvin]

LAL workshop: first step, throw a deprecation warning and at the next workshop, decide to remove the support.

[jrha]

N.B. ncm-filecopy appears to use shell => 1 for restart commands.

[jouvin]

Exactly, at least ncm-filecopy makes use of it. This seems difficult to remove it, except if we tokenize the command given for the restart property in filecopy. The goal of the deprecation warning was to better identify all the circumstances where a shell is used. I'm afraid that there is a couple of grid components also rely on this feature but I don't remember precisely.

[jrha]

AFAICT it's only ncm-glitestartup

[jrha]

As discussed we need a migration strategy for (at least) filecopy that does not place a burden on sites when upgrading.

[jrha]

No consensus yet, hopefully we can discuss at workshop.

[jrha]

Discussed at workshop, an option to reduce usage of subshell in filecopy would be to allow a list (or list of lists) of command + arguments for the restart command.

[jrha]

Another option would be to try and reduce what we consider to be acceptable in the restart field.

[jrha]

Consensus seems to be that this is too hard to solve and we should very strongly discourage use of subshells during PR reviews.