Merged in phstsai/node-exporter-dockerfile (pull request #2)

add the dockerfile for node-exporter

Approved-by: Hung-Wei Chiu <[email protected]>

dockerfiles/node-exporter/Dockerfile

@@ -0,0 +1,13 @@
+# Build stage
+FROM golang:1.7.3 AS builder
+RUN go get github.com/prometheus/node_exporter
+COPY ./src/node-exporter/ /go/src/github.com/prometheus/node_exporter/collector
+WORKDIR /go/src/github.com/prometheus/node_exporter
+RUN make build test
+
+# the final image
+FROM alpine:3.7
+COPY --from=builder /go/src/github.com/prometheus/node_exporter/node_exporter /bin/node_exporter
+EXPOSE      9100
+ENTRYPOINT  [ "/bin/node_exporter" ]
+

src/node-exporter/netdev_iface_common.go

@@ -0,0 +1,66 @@
+//phstsai
+package collector
+
+import (
+	"fmt"
+	"net"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type netIfaceCollector struct {
+	subsystem   string
+	metricDescs map[string]*prometheus.Desc
+}
+
+func init() {
+	registerCollector("iface", defaultEnabled, NewNetIfaceCollector)
+}
+
+// NewNetIfaceCollector returns a new Collector exposing network device stats.
+func NewNetIfaceCollector() (Collector, error) {
+	return &netIfaceCollector{
+		subsystem:   "network",
+		metricDescs: map[string]*prometheus.Desc{},
+	}, nil
+}
+
+func (c *netIfaceCollector) Update(ch chan<- prometheus.Metric) error {
+	netDevDefault, err := getDefaultDev()
+	if err != nil {
+		return fmt.Errorf("couldn't get default network devices: %s", err)
+	}
+
+	for key, value := range netDevDefault {
+		desc, ok := c.metricDescs[key]
+
+		if !ok {
+			desc = prometheus.NewDesc(
+				prometheus.BuildFQName(namespace, c.subsystem, "interface"),
+				fmt.Sprintf("List network devices and label the default one."),
+				[]string{"device"},
+				nil,
+			)
+			c.metricDescs[key] = desc
+		}
+
+		ch <- prometheus.MustNewConstMetric(desc, prometheus.GaugeValue, float64(value), key)
+	}
+	return nil
+}
+
+func Split(r rune) bool {
+	return r == ' ' || r == '\t'
+}
+
+func getNetDev() (map[string]int, error) {
+	netDev := map[string]int{}
+
+	ifaces, _ := net.Interfaces()
+
+	for _, iface := range ifaces {
+		netDev[iface.Name] = 0
+	}
+
+	return netDev, nil
+}

src/node-exporter/netdev_iface_common_test.go

@@ -0,0 +1,45 @@
+package collector
+
+import (
+	"fmt"
+	"os/exec"
+	"runtime"
+	"strings"
+	"testing"
+)
+
+func TestGetDefaultDev(t *testing.T) {
+	iface := ""
+	defaultInterface := ""
+
+	switch runtime.GOOS {
+	case "linux":
+		out, err := exec.Command("bash", "-c", "ip route get 8.8.8.8 | awk 'NR==1 {print $5}'").Output()
+		if err != nil {
+			t.Error("Can't get the interface for default route, maybe the system does not have the network connectivity", err)
+		}
+		//the output should look like eth0
+		fmt.Sscanf(string(out), "%s", &defaultInterface)
+		if defaultInterface == "" {
+			t.Error("Parse the interface fail")
+		}
+	case "darwin":
+		// skip the test for osx
+		t.Skip("Skip the test when os is drawin.")
+	}
+
+	netDevDefault, err := getDefaultDev()
+	if err != nil {
+		t.Error("couldn't get default network devices", err)
+	}
+
+	for key, value := range netDevDefault {
+		if value == 1 {
+			iface = key
+		}
+	}
+
+	if strings.Compare(defaultInterface, iface) != 0 {
+		t.Error("Default interface didn't match the result from getDefaultDev().")
+	}
+}

src/node-exporter/netdev_iface_darwin.go

@@ -0,0 +1,48 @@
+package collector
+
+import (
+	"errors"
+	"fmt"
+	"os/exec"
+)
+
+/*
+#include <stdio.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <ifaddrs.h>
+#include <net/if.h>
+*/
+import "C"
+
+func getDefaultDev() (map[string]int, error) {
+	iface := ""
+	netDev := map[string]int{}
+
+	var ifap, ifa *C.struct_ifaddrs
+	if C.getifaddrs(&ifap) == -1 {
+		return nil, errors.New("getifaddrs() failed")
+	}
+	defer C.freeifaddrs(ifap)
+
+	for ifa = ifap; ifa != nil; ifa = ifa.ifa_next {
+		if ifa.ifa_addr.sa_family == C.AF_LINK {
+			dev := C.GoString(ifa.ifa_name)
+			netDev[dev] = 0
+		}
+	}
+
+	out, err := exec.Command("bash", "-c", "route -n get default | grep interface").Output()
+	if err != nil {
+		return nil, fmt.Errorf("Couldn't get network devices: %s", err)
+	}
+
+	fmt.Sscanf(string(out), "  interface:%s", &iface)
+	if iface == "" {
+		return nil, fmt.Errorf("Parse the interface fail")
+	}
+
+	netDev[iface] = 1
+
+	return netDev, nil
+}

src/node-exporter/netdev_iface_linux.go

@@ -0,0 +1,44 @@
+package collector
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+)
+
+func getDefaultDev() (map[string]int, error) {
+	// /proc/net/route stores the kernel's routing table
+	// The interface whose destination is 00000000 is the interface of the default gateway
+	file, err := os.Open("/proc/net/route")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer file.Close()
+
+	netDev, err := getNetDev()
+	if err != nil {
+		return nil, fmt.Errorf("couldn't get network devices: %s", err)
+	}
+
+	scanner := bufio.NewScanner(file)
+	scanner.Scan()
+	for scanner.Scan() {
+		if scanner.Text() == "" {
+			break
+		}
+		s := strings.FieldsFunc(scanner.Text(), Split)
+		if s[1] == "00000000" {
+			netDev[s[0]] = 1
+		}
+	}
+
+	if err := scanner.Err(); err != nil {
+		log.Fatal(err)
+		return nil, err
+	}
+
+	return netDev, nil
+
+}