Detects hostname/interface ip

- Hostname is monitor's id. Incidents will be created with the monitor id.

system/config.go

@@ -0,0 +1,24 @@
+package system
+
+import (
+	"net"
+	"os"
+)
+
+// GetHostname returns id of the current system
+func GetHostname() string {
+	hostname, err := os.Hostname()
+	if err != nil || len(hostname) == 0 {
+		addrs, err := net.InterfaceAddrs()
+
+		if err != nil {
+			return "unknown"
+		}
+
+		for _, addr := range addrs {
+			return addr.String()
+		}
+	}
+
+	return hostname
+}