Fix solaris build

common/sigar.go

@@ -13,7 +13,7 @@
 // along with this program. If not, see
 // <http://www.mongodb.com/licensing/server-side-public-license>.
 
-// +build !freebsd,!darwin
+// +build !freebsd,!darwin,!solaris
 
 package common
 

common/sigar_solaris.go

@@ -0,0 +1,28 @@
+// Copyright (C) 2020 Graylog, Inc.
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the Server Side Public License, version 1,
+// as published by MongoDB, Inc.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// Server Side Public License for more details.
+//
+// You should have received a copy of the Server Side Public License
+// along with this program. If not, see
+// <http://www.mongodb.com/licensing/server-side-public-license>.
+
+package common
+
+func GetCpuIdle() float64 {
+	return -1
+}
+
+func GetFileSystemList75(string) []string {
+	return []string{}
+}
+
+func GetLoad1() float64 {
+	return -1
+}