Why is socat wrapper is run in a fork? [question]

[KostyaEsmukov]

Hello,

Please explain why is socat wrapper (network-wrapper.js) is run in a fork? Does it provide a lot of output thus blocking the event loop or was it just a historical decision?

It's not an obvious decision anyway, and it would be better (IMO) to include this functionality in the core LR process (except if there is a real need for a separate event loop here).

Related to #19

Kind regards, Kostya.

[npeditto]

Hi Kostya,

in the past we decided to create a socat wrapper in order to manage in modular way the socat process avoiding the to make an all-in-one process that could be crash. In this way if there is a problem in the socat process we avoid to compromise the main LR one. Moreover, in this way we can trigger easly the events occurred during the tunnels creation phases. Of course it was also possible to create a single process but at the expense of the process modularity.

Nicola

[KostyaEsmukov]

Hi Nicola,

I guess the only advantage of running socat wrapper in a separate process is avoiding a lock of the core process's event loop by too often stdout/stderr events.

Handling crashes gently is harder than in an all-in-one-process approach:

• child crash - that's easy - we should just start another one;
• parent crash - we should make sure that the child process exits right with the parent (see the cite below). I hope that broken IPC/stdio pipes will cope with it conveniently;
• socat crash - can be handled by either child or parent process.

OK, I will leave it as a separate process while taking into account the cases above.

Thank you.

options.detached

Note that child processes may continue running after the parent exits regardless of whether they are detached or not. See setsid(2) for more information. https://nodejs.org/api/child_process.html#child_process_options_detached