nginx.service - A high performance web server and a reverse proxy server
   Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
   Active: failed (Result: exit-code) since Thu 2017-03-30 20:32:45 UTC; 43s ago
  Process: 7527 ExecStop=/sbin/start-stop-daemon --quiet --stop --retry QUIT/5 --pidfile /run/nginx.pid (
  Process: 5702 ExecStart=/usr/sbin/nginx -g daemon on; master_process on; (code=exited, status=0/SUCCESS
  Process: 7532 ExecStartPre=/usr/sbin/nginx -t -q -g daemon on; master_process on; (code=exited, status=
 Main PID: 5705 (code=exited, status=0/SUCCESS)

Mar 30 20:32:45 ip-172-31-41-167 systemd[1]: Starting A high performance web server and a reverse proxy s
Mar 30 20:32:45 ip-172-31-41-167 nginx[7532]: nginx: [emerg] could not build server_names_hash, you shoul
Mar 30 20:32:45 ip-172-31-41-167 nginx[7532]: nginx: configuration file /etc/nginx/nginx.conf test failed
Mar 30 20:32:45 ip-172-31-41-167 systemd[1]: nginx.service: Control process exited, code=exited status=1
Mar 30 20:32:45 ip-172-31-41-167 systemd[1]: Failed to start A high performance web server and a reverse
Mar 30 20:32:45 ip-172-31-41-167 systemd[1]: nginx.service: Unit entered failed state.
Mar 30 20:32:45 ip-172-31-41-167 systemd[1]: nginx.service: Failed with result 'exit-code'.