Added sockstat test file

initial work on sockstat work

Fixed package name

Finished implementation of the sockstat plugin

missed a return value

Added sockstat to default plugins to start

Fixed scanner read on sockstat

fixed sockstat linux test for TCP alloc

update sockstat test case

Updated sockstat to return TCP and UDP memory in bytes instead of page count

collector/sockstat_linux.go

@@ -0,0 +1,114 @@
+// +build !nonetstat
+
+package collector
+
+import (
+	"bufio"
+	"fmt"
+	"github.com/prometheus/client_golang/prometheus"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	procSockStat      = "/proc/net/sockstat"
+	sockStatSubsystem = "sockstat"
+)
+
+// Used for calculating the total memory bytes on TCP and UDP
+var pageSize = os.Getpagesize()
+
+type sockStatCollector struct {
+	metrics map[string]prometheus.Gauge
+}
+
+func init() {
+	Factories["sockstat"] = NewSockStatCollector
+}
+
+// NewSockStatCollector returns a new Collector exposing socket stats
+func NewSockStatCollector() (Collector, error) {
+	return &sockStatCollector{
+		metrics: map[string]prometheus.Gauge{},
+	}, nil
+}
+
+func (c *sockStatCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	sockStats, err := getSockStats(procSockStat)
+	if err != nil {
+		return fmt.Errorf("couldn't get sockstats: %s", err)
+	}
+	for protocol, protocolStats := range sockStats {
+		for name, value := range protocolStats {
+			key := protocol + "_" + name
+			if _, ok := c.metrics[key]; !ok {
+				c.metrics[key] = prometheus.NewGauge(
+					prometheus.GaugeOpts{
+						Namespace: Namespace,
+						Subsystem: sockStatSubsystem,
+						Name:      key,
+						Help:      fmt.Sprintf("%s %s from /proc/net/sockstat.", protocol, name),
+					},
+				)
+			}
+			v, err := strconv.ParseFloat(value, 64)
+			if err != nil {
+				return fmt.Errorf("invalid value %s in sockstats: %s", value, err)
+			}
+			c.metrics[key].Set(v)
+		}
+	}
+	for _, m := range c.metrics {
+		m.Collect(ch)
+	}
+	return err
+}
+
+func getSockStats(fileName string) (map[string]map[string]string, error) {
+	file, err := os.Open(fileName)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	return parseSockStats(file, fileName)
+}
+
+func parseSockStats(r io.Reader, fileName string) (map[string]map[string]string, error) {
+	var (
+		sockStat = map[string]map[string]string{}
+		scanner  = bufio.NewScanner(r)
+	)
+
+	for scanner.Scan() {
+		line := strings.Split(string(scanner.Text()), " ")
+		// Remove trailing :
+		protocol := line[0][:len(line[0])-1]
+		sockStat[protocol] = map[string]string{}
+
+		for i := 1; i < len(line) && i+1 < len(line); i++ {
+			sockStat[protocol][line[i]] = line[i+1]
+			i++
+		}
+	}
+
+	// The mem options are reported in pages
+	// Multiply them by the pagesize to get bytes
+	// Update TCP Mem
+	pageCount, err := strconv.Atoi(sockStat["TCP"]["mem"])
+	if err != nil {
+		return nil, fmt.Errorf("invalid value %s in sockstats: %s", sockStat["TCP"]["mem"], err)
+	}
+	sockStat["TCP"]["mem"] = strconv.Itoa(pageCount * pageSize)
+
+	// Update UDP Mem
+	pageCount, err = strconv.Atoi(sockStat["UDP"]["mem"])
+	if err != nil {
+		return nil, fmt.Errorf("invalid value %s in sockstats: %s", sockStat["UDP"]["mem"], err)
+	}
+	sockStat["UDP"]["mem"] = strconv.Itoa(pageCount * pageSize)
+
+	return sockStat, nil
+}