FreeBSD compatibility

- Use gopsutils istead of gosigar
- Bump go-dockerclient

closes #372

plugins/system/system.go

@@ -1,7 +1,12 @@
 package system
 
 import (
-	"github.com/cloudfoundry/gosigar"
+	"bufio"
+	"bytes"
+	"fmt"
+
+	"github.com/shirou/gopsutil/host"
+	"github.com/shirou/gopsutil/load"
 
 	"github.com/influxdb/telegraf/plugins"
 )
@@ -22,25 +27,50 @@ func (_ *SystemStats) add(acc plugins.Accumulator,
 }
 
 func (_ *SystemStats) Gather(acc plugins.Accumulator) error {
-	loadavg := sigar.LoadAverage{}
-	if err := loadavg.Get(); err != nil {
+	loadavg, err := load.LoadAvg()
+	if err != nil {
 		return err
 	}
 
-	uptime := sigar.Uptime{}
-	if err := uptime.Get(); err != nil {
+	hostinfo, err := host.HostInfo()
+	if err != nil {
 		return err
 	}
 
-	acc.Add("load1", loadavg.One, nil)
-	acc.Add("load5", loadavg.Five, nil)
-	acc.Add("load15", loadavg.Fifteen, nil)
-	acc.Add("uptime", uptime.Length, nil)
-	acc.Add("uptime_format", uptime.Format(), nil)
+	acc.Add("load1", loadavg.Load1, nil)
+	acc.Add("load5", loadavg.Load5, nil)
+	acc.Add("load15", loadavg.Load15, nil)
+	acc.Add("uptime", hostinfo.Uptime, nil)
+	acc.Add("uptime_format", format_uptime(hostinfo.Uptime), nil)
 
 	return nil
 }
 
+func format_uptime(uptime uint64) string {
+	buf := new(bytes.Buffer)
+	w := bufio.NewWriter(buf)
+
+	days := uptime / (60 * 60 * 24)
+
+	if days != 0 {
+		s := ""
+		if days > 1 {
+			s = "s"
+		}
+		fmt.Fprintf(w, "%d day%s, ", days, s)
+	}
+
+	minutes := uptime / 60
+	hours := minutes / 60
+	hours %= 24
+	minutes %= 60
+
+	fmt.Fprintf(w, "%2d:%02d", hours, minutes)
+
+	w.Flush()
+	return buf.String()
+}
+
 func init() {
 	plugins.Add("system", func() plugins.Plugin {
 		return &SystemStats{}