Add linux conntrack collector.

collector/conntrack_linux.go

@@ -0,0 +1,81 @@
+// Copyright 2015 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !noconntrack
+
+package collector
+
+import (
+	"io/ioutil"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+type conntrackCollector struct {
+	current *prometheus.Desc
+	limit   *prometheus.Desc
+}
+
+func init() {
+	Factories["conntrack"] = NewConntrackCollector
+}
+
+// Takes a prometheus registry and returns a new Collector exposing
+// conntrack stats
+func NewConntrackCollector() (Collector, error) {
+	return &conntrackCollector{
+		current: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, "", "nf_conntrack_entries"),
+			"Number of currently allocated flow entries for connection tracking.",
+			nil, nil,
+		),
+		limit: prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, "", "nf_conntrack_entries_limit"),
+			"Maximum size of connection tracking table.",
+			nil, nil,
+		),
+	}, nil
+}
+
+func (c *conntrackCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	value, err := readUintFromFile(procFilePath("sys/net/netfilter/nf_conntrack_count"))
+	if err != nil {
+		// Conntrack probably not loaded into the kernel.
+		return nil
+	}
+	ch <- prometheus.MustNewConstMetric(
+		c.current, prometheus.GaugeValue, float64(value))
+
+	value, err = readUintFromFile(procFilePath("sys/net/netfilter/nf_conntrack_max"))
+	if err != nil {
+		return nil
+	}
+	ch <- prometheus.MustNewConstMetric(
+		c.limit, prometheus.GaugeValue, float64(value))
+
+	return nil
+}
+
+func readUintFromFile(path string) (uint64, error) {
+	data, err := ioutil.ReadFile(path)
+	if err != nil {
+		return 0, err
+	}
+	value, err := strconv.ParseUint(strings.TrimSpace(string(data)), 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	return value, nil
+}

collector/fixtures/e2e-output.txt

@@ -1274,6 +1274,12 @@ node_network_transmit_packets{device="lxcbr0"} 28339
 node_network_transmit_packets{device="tun0"} 934
 node_network_transmit_packets{device="veth4B09XN"} 10640
 node_network_transmit_packets{device="wlan0"} 1.17262e+07
+# HELP node_nf_conntrack_entries Number of currently allocated flow entries for connection tracking.
+# TYPE node_nf_conntrack_entries gauge
+node_nf_conntrack_entries 123
+# HELP node_nf_conntrack_entries_limit Maximum size of connection tracking table.
+# TYPE node_nf_conntrack_entries_limit gauge
+node_nf_conntrack_entries_limit 65536
 # HELP node_procs_blocked Number of processes blocked waiting for I/O to complete.
 # TYPE node_procs_blocked gauge
 node_procs_blocked 0

collector/fixtures/proc/sys/net/netfilter/nf_conntrack_count

@@ -0,0 +1 @@
+123

collector/fixtures/proc/sys/net/netfilter/nf_conntrack_max

@@ -0,0 +1 @@
+65536

end-to-end-test.sh

@@ -42,7 +42,7 @@ fi
 ./node_exporter \
   -collector.procfs="collector/fixtures/proc" \
   -collector.sysfs="collector/fixtures/sys" \
-  -collectors.enabled="diskstats,filefd,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,bonding,megacli" \
+  -collectors.enabled="conntrack,diskstats,filefd,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,bonding,megacli" \
   -collector.textfile.directory="collector/fixtures/textfile/two_metric_files/" \
   -collector.megacli.command="collector/fixtures/megacli" \
   -web.listen-address "127.0.0.1:${port}" \

node_exporter.go

@@ -42,7 +42,7 @@ var (
 	listenAddress     = flag.String("web.listen-address", ":9100", "Address on which to expose metrics and web interface.")
 	metricsPath       = flag.String("web.telemetry-path", "/metrics", "Path under which to expose metrics.")
 	enabledCollectors = flag.String("collectors.enabled",
-		filterAvailableCollectors("diskstats,filefd,filesystem,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,time,uname"),
+		filterAvailableCollectors("conntrack,diskstats,filefd,filesystem,loadavg,mdadm,meminfo,netdev,netstat,sockstat,stat,textfile,time,uname"),
 		"Comma-separated list of collectors to use.")
 	printCollectors = flag.Bool("collectors.print", false, "If true, print available collectors and exit.")