CentOS - Oct 2017 - sidekiq receives SIGHUP when started via ssh -t

Hi,

I have a couple of ideas how to fix it, but I'm trying to figure out
what's going on first. I mainly start this program (sidekiq) on Debian
systems, and it might be my first time running it under CentOS, so my
conjecture is that it has to do with differences between
distributions...

Now then, when I run it this way:

ssh user at example.com '. ~/.bash_profile && rvm 2.3.1 at gemset1
&& cd
path/to/site && bundle exec sidekiq -C config/sidekiq.yml -d -L
log/sidekiq.log'

it daemonizes itself and stays running. When I add -t switch (ssh -t
...), it gets terminated by SIGHUP.

On Ubuntu it stays running in both cases. What's happening here? Any
suggestions are welcome.

Regards,
Yuri

Hi,

I was able to narrow it down to this ruby script:

#!/usr/bin/env ruby
Process.daemon
while true
        sleep 1
end

And I can reproduce it on one particular CentOS server, on the other
CentOS server it works as on Ubuntu. The CentOS server where I can
reproduce the issue is supposed to have vanilla CentOS, but probably
not exactly.

So, when I run it this way on CentOS 7:

ssh user at example.com -t '. ~/.bash_profile && rvm 2.3.1
&& cd 1 && ./1.rb'

script doesn't stay, without -t it does. Under Ubuntu 16.04 it stays
in both cases.

I tried to reproduce it with bash:

#!/usr/bin/env bash
(setsid bash -c 'exec > /dev/null 2>&1 < /dev/null; while true;
do
        sleep 1
done') &

But it behaves consistently across servers (with -t terminates on any
server I tried, without -t stays). I might be missing something here.

Any ideas are welcome. Like, what to check? Where and what to ask?

Regards,
Yuri

Hi,

I've just found the reason. From what I can see, on the server the
process received SIGHUP right after fork. It had no time to switch to
new session and detach from controlling terminal. And to work around
that one might add sleep to the end:

ssh user at example.com -t '. ~/.bash_profile && rvm 2.3.1
&& cd 1 &&
./1.rb && sleep 1'

or wait for pid file to be created, whatever.

Regards,
Yuri