# ==> /etc/systemd/system/yahns@.service <==
# Since SIGUSR2 upgrades do not work under systemd, this service
# file allows starting two (or more) simultaneous services
# during upgrade (e.g. yahns@1 and yahns@2) with the intention
# that they are both running during the upgrade process.
#
# This allows upgrading without downtime, using yahns@2 as a
# temporary hot spare:
#
#   systemctl start yahns@2
#   sleep 2 # wait for yahns@2 to boot, increase as necessary for big apps
#   systemctl restart yahns@1
#   sleep 2 # wait for yahns@1 to warmup
#   systemctl stop yahns@2

[Unit]
Description = yahns Ruby server %i
Wants = yahns.socket
After = yahns.socket

[Service]
# yahns can handle lots of open files:
LimitNOFILE = 32768
LimitCORE = infinity

# The listen socket we give yahns should be blocking for optimal
# load distribution between processes under the Linux kernel.
# NonBlocking is false by default in systemd, but we specify it
# here anyways to discourage users from blindly changing it.
Sockets = yahns.socket
NonBlocking = false

# bundler users must use the "--keep-file-descriptors" switch, here:
# ExecStart = /path/to/bin/bundle exec --keep-file-descriptors yahns -c ...
ExecStart = /path/to/bin/yahns -c /path/to/yahns.conf.rb
KillSignal = SIGQUIT
User = www-data
Group = www-data
ExecReload = /bin/kill -HUP $MAINPID

# this should match the shutdown_timeout value in yahns_config(5)
TimeoutStopSec = 600

# Only kill the master process, it may be harmful to signal
# workers via default "control-group" setting since some
# Ruby extensions and applications misbehave on interrupts
KillMode = process

[Install]
WantedBy = multi-user.target