[erlang-questions] erlang + systemd

[Peter Lemenkov]

2014-03-19 12:16 GMT+04:00 Benoit Chesneau <bchesneau@REDACTED>:
> Hi all,
>
> I am looking for a simple way to launch an erlang release using
> systemd and in particularly using the socket activations
> possibilities.
>
> Form my understanding epmd is not systemd aware for now. Eclus [1]
> allows to do that. Is there any other tool around? Did someone start
> to patch the vm?

There are two things which are necessary.

First one is to allow socket activation in Erlang Port mapping Daemon
as you said. There are two possible ways to do so - either replace
stock epmd with eclus (which works quite well and offers you a few
more nice things - d-bus publishing/subscribing etc), or apply this
patch to the epmd made by Matwey Kornilov -
https://github.com/matwey/otp/tree/systemd . Matwey's approach looks
slightly better in a short term since eclus won't work on a obscure
architectures such as PowerPC / Tilera / MIPS / s390x, so we're going
to apply Matwey's patch in Fedora / RHEL 7.

After one fixes an issue with epmd, there is another necessary thingto
do - to pass sockets to Erlang releases. It looks possible and
gen_udp/gen_tcp already has an option to re-use fd opened elsewhere
(see  {fd, integer()} option). But I'm not sure if it works with
systemd or not.
-- 
With best regards, Peter Lemenkov.