[SOLVED] 502 Bad Gateway after upgrade to 2.7.0beta2

Updated from cli:

cd /var/discourse
git pull
 ./launcher rebuild app

Everything went ok but I got 502 Bad Gateway error.

docker ps

CONTAINER ID   IMAGE                 COMMAND        CREATED          STATUS          PORTS                  NAMES
6598e9407e29   local_discourse/app   "/sbin/boot"   35 minutes ago   Up 22 minutes   0.0.0.0:2045->80/tcp   app

./launcher logs app

(105) exiting
ok: run: redis: (pid 47) 17s
ok: run: postgres: (pid 44) 17s
supervisor pid: 114 unicorn pid: 118
config/unicorn_launcher: line 71: kill: (118) - No such process
config/unicorn_launcher: line 15: kill: (118) - No such process
(114) exiting
ok: run: redis: (pid 47) 21s
ok: run: postgres: (pid 44) 21s
supervisor pid: 123 unicorn pid: 127
config/unicorn_launcher: line 71: kill: (127) - No such process
config/unicorn_launcher: line 15: kill: (127) - No such process
(123) exiting
ok: run: redis: (pid 47) 26s
ok: run: postgres: (pid 44) 26s
supervisor pid: 132 unicorn pid: 136

curl localhost:2045

<html>
<head><title>502 Bad Gateway</title></head>
<body>
<center><h1>502 Bad Gateway</h1></center>
<hr><center>nginx</center>
</body>
</html>

Discourse running inside LXC container, my second forum also inside LXC container works fine after update. Really strange.
Any advice?

Update:
I see that some ruby process is still running and eating lot of cpu:

/usr/local/bin/ruby /usr/local/bin/bundle exec config/unicorn_launcher -E production -c config/unicorn.conf.rb

Update2:
Solved by changind LXC unprivileged to privileged container.