Merge branch 'systemd'

Adds a systemd service setup for sshlog.

* systemd:
  Add information about util directory
  Add a README inside utils with systemd instructions
  Add sshlog.service configuration

README.md

@@ -41,3 +41,7 @@ FLAGS:
   -4, --onlyIPv4      Only listens on IPv4.
   -p, --port string   Port to listen for incoming connections. (default "22"))
 ```
+
+# Utils
+Inside the `util` directory you might find some additional information like how to create Systemd service for sshlog.
+

util/README.md

@@ -0,0 +1,15 @@
+# Utility
+A collection of scripts and useful configurations.
+
+## Systemd
+You can use the example `sshlog.service` to run `sshlog` as a service under Systemd.
+
+Copy the `sshlog.service` into `/etc/systemd/system/sshlog.service` and change the `ExecStart` value to point to the `sshlog` executable.
+If you installed it with `go install` it will be propably located inside your `$GOPATH/bin` directory. Use the full path as
+value for the `ExecStart` parameter. This is also the location if you wannt to give it some arguments like `-p 2222` for the listening port.
+
+After saving the configuration under `/etc/systemd/system/sshlog.service` it can be started with `systemctl start sshlog.service` and
+enabled to run on system boot with `systemctl enable sshlog.service`
+
+While running it with Systemd all logs can be accesst with `journalctl -u sshlog.service`.
+

util/sshlog.service

@@ -0,0 +1,41 @@
+[Unit]
+Description=SSH Auth Logging
+Requires=network-online.target
+
+[Service]
+Type=simple
+Restart=always
+RestartSec=30sec
+# Path to the executable
+ExecStart=/home/user/go/bin/sshlog -p 2222
+KillSignal=SIGTERM
+
+# Stop trying to restart the service if it restarts too many times in a row
+StartLimitInterval=5min
+StartLimitBurst=4
+
+StandardOutput=journal
+StandardError=journal
+StandardInput=null
+
+DynamicUser=yes
+
+PrivateTmp=true
+PrivateDevices=true
+PrivateMounts=true
+ProtectSystem=full
+#ProtectHome=true
+RestrictNamespaces=true
+InaccessiblePaths=/run /var /etc
+
+PrivateUsers=true
+
+NoNewPrivileges=true
+ProtectKernelTunables=true
+ProtectKernelModules=true
+ProtectKernelLogs=true
+ProtectControlGroups=true
+MemoryDenyWriteExecute=true
+
+[Install]
+WantedBy=multi-user.target