Attempt on consul collector

collector/consul.go

+// +build !noconsul
+
+package collector
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io"
+	"os/exec"
+	"strconv"
+	"strings"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+const (
+	consulSubsystem = "consul"
+)
+
+var (
+	consulBinary = flag.String("consul.binary", "consul", "Location of the consul binary")
+
+	consulIgnoredFields = map[string]struct{}{
+		"arch":    struct{}{},
+		"os":      struct{}{},
+		"state":   struct{}{},
+		"version": struct{}{},
+	}
+	consulIgnoredKeys = map[string]struct{}{
+		"build": struct{}{},
+	}
+)
+
+func init() {
+	Factories["consul"] = NewConsulCollector
+}
+
+type consulCollector struct {
+	metrics map[string]prometheus.Gauge
+}
+
+// NewConsulCollector returns the collector implementation to export Consul
+// internals.
+func NewConsulCollector(config Config) (Collector, error) {
+	return &consulCollector{
+		metrics: map[string]prometheus.Gauge{},
+	}, nil
+}
+
+func (c *consulCollector) Update(metricc chan<- prometheus.Metric) error {
+	stats, err := getConsulStats()
+	if err != nil {
+		return fmt.Errorf("consul info failed: %s", err)
+	}
+
+	for name, value := range stats {
+		if _, ok := c.metrics[name]; !ok {
+			c.metrics[name] = prometheus.NewGauge(
+				prometheus.GaugeOpts{
+					Namespace: consulSubsystem,
+					Name:      name,
+					Help:      fmt.Sprintf("%s from consul info", name),
+				},
+			)
+		}
+
+		c.metrics[name].Set(float64(value))
+	}
+
+	for _, m := range c.metrics {
+		m.Collect(metricc)
+	}
+
+	return nil
+}
+
+type consulStats map[string]int64
+
+func getConsulStats() (consulStats, error) {
+	info := exec.Command(*consulBinary, "info")
+
+	outPipe, err := info.StdoutPipe()
+	if err != nil {
+		return nil, err
+	}
+
+	if err := info.Start(); err != nil {
+		return nil, err
+	}
+
+	stats, err := parseConsulStats(outPipe)
+	if err != nil {
+		return nil, err
+	}
+
+	if err := info.Wait(); err != nil {
+		return nil, err
+	}
+
+	return stats, nil
+}
+
+func parseConsulStats(r io.Reader) (consulStats, error) {
+	var (
+		s     = bufio.NewScanner(r)
+		stats = consulStats{}
+
+		key string
+	)
+
+	for s.Scan() {
+		line := strings.TrimSpace(s.Text())
+
+		if strings.Contains(line, ":") {
+			key = strings.TrimSuffix(line, ":")
+		}
+
+		if _, ok := consulIgnoredKeys[key]; ok {
+			continue
+		}
+
+		if strings.Contains(line, "=") {
+			var (
+				parts        = strings.SplitN(line, "=", 2)
+				field, value = strings.TrimSpace(parts[0]), strings.TrimSpace(parts[1])
+				name         = strings.Join([]string{key, field}, "_")
+			)
+
+			if _, ok := consulIgnoredFields[field]; ok {
+				continue
+			}
+
+			switch value {
+			case "true":
+				stats[name] = 1
+			case "false":
+				stats[name] = 0
+			default:
+				i, err := strconv.ParseInt(value, 10, 64)
+				if err != nil {
+					return nil, err
+				}
+				stats[name] = i
+			}
+		}
+	}
+	if err := s.Err(); err != nil {
+		return nil, err
+	}
+
+	return stats, nil
+}

collector/consul_test.go

+package collector
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestConsulAgentInput(t *testing.T) {
+	var (
+		output = `
+agent:
+        check_monitors = 0
+        check_ttls = 0
+        checks = 0
+        services = 8
+build:
+        prerelease =
+        revision = 461c1e18
+        version = 0.4.2.soundcloud4
+consul:
+        known_servers = 3
+        server = false
+runtime:
+        arch = amd64
+        cpu_count = 1
+        goroutines = 36
+        max_procs = 16
+        os = linux
+        version = go1.3
+serf_lan:
+        event_queue = 0
+        event_time = 55
+        failed = 0
+        intent_queue = 0
+        left = 0
+        member_time = 116
+        members = 11
+        query_queue = 0
+        query_time = 1
+`
+
+		r = bytes.NewBufferString(output)
+	)
+
+	stats, err := parseConsulStats(r)
+	if err != nil {
+		t.Fatalf("parse failed: %s", err)
+	}
+
+	if want, got := 18, len(stats); want != got {
+		t.Errorf("want %d, got %d", want, got)
+	}
+}
+
+func TestConsulServerInput(t *testing.T) {
+	var (
+		output = `
+agent:
+        check_monitors = 0
+        check_ttls = 0
+        checks = 0
+        services = 4
+build:
+        prerelease =
+        revision = 461c1e18
+        version = 0.4.2.soundcloud4
+consul:
+        bootstrap = false
+        known_datacenters = 1
+        leader = true
+        server = true
+raft:
+        applied_index = 1712470
+        commit_index = 1712470
+        fsm_pending = 0
+        last_contact = 0
+        last_log_index = 1712470
+        last_log_term = 131
+        last_snapshot_index = 1708783
+        last_snapshot_term = 131
+        num_peers = 2
+        state = Leader
+        term = 131
+runtime:
+        arch = amd64
+        cpu_count = 1
+        goroutines = 81
+        max_procs = 16
+        os = linux
+        version = go1.3
+serf_lan:
+        event_queue = 0
+        event_time = 55
+        failed = 0
+        intent_queue = 0
+        left = 0
+        member_time = 116
+        members = 11
+        query_queue = 0
+        query_time = 1
+serf_wan:
+        event_queue = 0
+        event_time = 1
+        failed = 0
+        intent_queue = 0
+        left = 0
+        member_time = 1
+        members = 1
+        query_queue = 0
+        query_time = 1
+`
+		r = bytes.NewBufferString(output)
+	)
+
+	stats, err := parseConsulStats(r)
+	if err != nil {
+		t.Fatalf("parse failed: %s", err)
+	}
+
+	if want, got := 39, len(stats); want != got {
+		t.Errorf("want %d, got %d", want, got)
+	}
+}