A Simple Systemd Service for NATS

2016-04-09

NATS

systemd

Here's a simple NATS gnatsd service for Systemd, which starts gnatsd on boot and restarts it in case it crashes (which is highly unlikely). I assume you've already downloaded the gnatsd executable and placed it in /opt/bin/gnatsd.

Save the configuraton below as /etc/systemd/system/gnatsd.service:

[Unit]
Description=NATS server

[Service]
ExecStart=/opt/bin/gnatsd
Restart=on-failure

[Install]
WantedBy=multi-user.target

You can now start the service using:

$ sudo systemctl start gnatsd.service

Confirm that gnatsd is running:

$ printf "PING\r\n" | nc localhost 4222
# Output:
INFO {"server_id":"68348d45b8246e8c1a1fb6c37a940d61","version":"0.7.2","go":"go1.5.2","host":"0.0.0.0","port":4222,"auth_required":false,"ssl_required":false,"tls_required":false,"tls_verify":false,"max_payload":1048576}
PONG

Retrieve info about the service:

$ systemctl status gnatsd.service
# Output:
● gnatsd.service - NATS server
   Loaded: loaded (/etc/systemd/system/gnatsd.service; disabled; vendor preset: enabled)
   Active: active (running) since Fri 2016-04-08 21:02:23 EDT; 2min 47s ago
 Main PID: 1726 (gnatsd)
   CGroup: /system.slice/gnatsd.service
           └─1726 /opt/bin/gnatsd

In order to make the service start on boot, we need to enable it:

$ sudo systemctl enable gnatsd.service

You can restart the service (e.g., when the gnatsd configuration changes):

$ sudo systemctl restart gnatsd.service

gnatsd will support reloading the configuration without restarting soon, so the following will be available:

$ sudo systemctl reload gnatsd.service

You can stop the service:

$ sudo systemctl stop gnatsd.service

Or disable it, so it won't start on boot:

$ sudo systemctl disable gnatsd.service

yüce's blog

A Simple Systemd Service for NATS