Extract bind statistics parsing in sub-packages

This prepares the addition of statistics v3 parsing.

bind/client.go

@@ -0,0 +1,60 @@
+package bind
+
+// Client queries the BIND API, parses the response and returns stats in a
+// generic format.
+type Client interface {
+	Stats() (Statistics, error)
+}
+
+// Common bind field types.
+const (
+	QryRTT = "QryRTT"
+)
+
+// Statistics is a generic representation of BIND statistics.
+type Statistics struct {
+	Server struct {
+		IncomingQueries  []Stat
+		IncomingRequests []Stat
+		NSStats          []Stat
+	}
+	Views       []View
+	TaskManager TaskManager
+}
+
+// View represents a statistics for a single BIND view.
+type View struct {
+	Name            string
+	Cache           []Stat
+	ResolverStats   []Stat
+	ResolverQueries []Stat
+}
+
+// Stat represents a single counter value.
+type Stat struct {
+	Name    string
+	Counter uint
+}
+
+// Task represents a single running task.
+type Task struct {
+	ID         string `xml:"id"`
+	Name       string `xml:"name"`
+	Quantum    uint   `xml:"quantum"`
+	References uint   `xml:"references"`
+	State      string `xml:"state"`
+}
+
+// TaskManager contains information about all running tasks.
+type TaskManager struct {
+	Tasks       []Task      `xml:"tasks>task"`
+	ThreadModel ThreadModel `xml:"thread-model"`
+}
+
+// ThreadModel contains task and worker information.
+type ThreadModel struct {
+	Type           string `xml:"type"`
+	WorkerThreads  uint   `xml:"worker-threads"`
+	DefaultQuantum uint   `xml:"default-quantum"`
+	TasksRunning   uint   `xml:"tasks-running"`
+}

bind/v2/struct.go

@@ -1,19 +1,15 @@
-package main
+package v2
 
 import (
 	"encoding/xml"
-)
 
-const (
-	qryRTT = "QryRTT"
+	"github.com/digitalocean/bind_exporter/bind"
 )
 
 type Zone struct {
 	Name       string `xml:"name"`
 	Rdataclass string `xml:"rdataclass"`
 	Serial     string `xml:"serial"`
-	//TODO a zone can also have a huge number of counters
-	//              <counters>
 }
 
 type Stat struct {
@@ -42,26 +38,6 @@ type Socketmgr struct {
 	Sockets    []Socket `xml:"sockets>socket"`
 }
 
-type Task struct {
-	ID         string `xml:"id"`
-	Name       string `xml:"name"`
-	Quantum    uint   `xml:"quantum"`
-	References uint   `xml:"references"`
-	State      string `xml:"state"`
-}
-
-type ThreadModel struct {
-	Type           string `xml:"type"`
-	WorkerThreads  uint   `xml:"worker-threads"`
-	DefaultQuantum uint   `xml:"default-quantum"`
-	TasksRunning   uint   `xml:"tasks-running"`
-}
-
-type Taskmgr struct {
-	Tasks       []Task      `xml:"tasks>task"`
-	ThreadModel ThreadModel `xml:"thread-model"`
-}
-
 type QueriesIn struct {
 	Rdtype []Stat `xml:"rdtype"`
 }
@@ -71,24 +47,20 @@ type Requests struct {
 }
 
 type Server struct {
-	Requests  Requests  `xml:"requests"`   //Most important stats
-	QueriesIn QueriesIn `xml:"queries-in"` //Most important stats
+	Requests  Requests  `xml:"requests"`
+	QueriesIn QueriesIn `xml:"queries-in"`
 
 	NsStats     []Stat `xml:"nsstat"`
 	SocketStats []Stat `xml:"socketstat"`
 	ZoneStats   []Stat `xml:"zonestats"`
 }
 
-type Memory struct {
-	//TODO
-}
-
 type Statistics struct {
-	Views     []View    `xml:"views>view"`
-	Socketmgr Socketmgr `xml:"socketmgr"`
-	Taskmgr   Taskmgr   `xml:"taskmgr"`
-	Server    Server    `xml:"server"`
-	Memory    Memory    `xml:"memory"`
+	Views     []View           `xml:"views>view"`
+	Socketmgr Socketmgr        `xml:"socketmgr"`
+	Taskmgr   bind.TaskManager `xml:"taskmgr"`
+	Server    Server           `xml:"server"`
+	Memory    struct{}         `xml:"memory"`
 }
 type Bind struct {
 	Statistics Statistics `xml:"statistics"`

bind/v2/v2.go

@@ -0,0 +1,79 @@
+package v2
+
+import (
+	"encoding/xml"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+
+	"github.com/digitalocean/bind_exporter/bind"
+)
+
+// Client implements bind.Client and can be used to query a BIND v2 API.
+type Client struct {
+	url  string
+	http *http.Client
+}
+
+// NewClient returns an initialized Client.
+func NewClient(url string, c *http.Client) *Client {
+	return &Client{
+		url:  url,
+		http: c,
+	}
+}
+
+// Stats implements bind.Stats.
+func (c *Client) Stats() (bind.Statistics, error) {
+	s := bind.Statistics{}
+
+	resp, err := c.http.Get(c.url)
+	if err != nil {
+		return s, fmt.Errorf("error querying stats: %s", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return s, fmt.Errorf("failed to read response: %s", err)
+	}
+
+	root := Isc{}
+	if err := xml.Unmarshal([]byte(body), &root); err != nil {
+		return s, fmt.Errorf("Failed to unmarshal XML response: %s", err)
+	}
+
+	stats := root.Bind.Statistics
+	for _, t := range stats.Server.QueriesIn.Rdtype {
+		s.Server.IncomingQueries = append(s.Server.IncomingQueries, stat(t))
+	}
+	for _, t := range stats.Server.Requests.Opcode {
+		s.Server.IncomingRequests = append(s.Server.IncomingRequests, stat(t))
+	}
+	for _, t := range stats.Server.NsStats {
+		s.Server.NSStats = append(s.Server.NSStats, stat(t))
+	}
+	for _, view := range stats.Views {
+		v := bind.View{Name: view.Name}
+		for _, t := range view.Cache {
+			v.Cache = append(v.Cache, stat(t))
+		}
+		for _, t := range view.Rdtype {
+			v.ResolverQueries = append(v.ResolverQueries, stat(t))
+		}
+		for _, t := range view.Resstat {
+			v.ResolverStats = append(v.ResolverStats, stat(t))
+		}
+		s.Views = append(s.Views, v)
+	}
+	s.TaskManager = stats.Taskmgr
+
+	return s, nil
+}
+
+func stat(s Stat) bind.Stat {
+	return bind.Stat{
+		Name:    s.Name,
+		Counter: s.Counter,
+	}
+}

bind_exporter.go

@@ -1,12 +1,10 @@
 package main
 
 import (
-	"encoding/xml"
 	"flag"
 	"fmt"
 	"io/ioutil"
 	"math"
-	"net"
 	"net/http"
 	_ "net/http/pprof"
 	"os"
@@ -14,6 +12,9 @@ import (
 	"strings"
 	"time"
 
+	"github.com/digitalocean/bind_exporter/bind"
+	"github.com/digitalocean/bind_exporter/bind/v2"
+
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/log"
 	"github.com/prometheus/common/version"
@@ -38,7 +39,7 @@ var (
 	incomingRequests = prometheus.NewDesc(
 		prometheus.BuildFQName(namespace, "", "incoming_requests_total"),
 		"Number of incomming DNS requests.",
-		[]string{"name"}, nil,
+		[]string{"opcode"}, nil,
 	)
 	resolverCache = prometheus.NewDesc(
 		prometheus.BuildFQName(namespace, resolver, "cache_rrsets"),
@@ -146,36 +147,21 @@ var (
 	)
 )
 
-// Exporter collects Binds stats from the given server and exports
-// them using the prometheus metrics package.
+// Exporter collects Binds stats from the given server and exports them using
+// the prometheus metrics package.
 type Exporter struct {
-	URI    string
-	client *http.Client
+	client bind.Client
 }
 
 // NewExporter returns an initialized Exporter.
-func NewExporter(uri string, timeout time.Duration) *Exporter {
+func NewExporter(url string, timeout time.Duration) *Exporter {
 	return &Exporter{
-		URI: uri,
-		client: &http.Client{
-			Transport: &http.Transport{
-				Dial: func(netw, addr string) (net.Conn, error) {
-					c, err := net.DialTimeout(netw, addr, timeout)
-					if err != nil {
-						return nil, err
-					}
-					if err := c.SetDeadline(time.Now().Add(timeout)); err != nil {
-						return nil, err
-					}
-					return c, nil
-				},
-			},
-		},
+		client: v2.NewClient(url, &http.Client{Timeout: timeout}),
 	}
 }
 
-// Describe describes all the metrics ever exported by the bind
-// exporter. It implements prometheus.Collector.
+// Describe describes all the metrics ever exported by the bind exporter. It
+// implements prometheus.Collector.
 func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 	ch <- up
 	ch <- incomingQueries
@@ -193,48 +179,29 @@ func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
 	ch <- workerThreads
 }
 
-// Collect fetches the stats from configured bind location and
-// delivers them as Prometheus metrics. It implements prometheus.Collector.
+// Collect fetches the stats from configured bind location and delivers them as
+// Prometheus metrics. It implements prometheus.Collector.
 func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
-	var status float64
-	defer func() {
-		ch <- prometheus.MustNewConstMetric(up, prometheus.GaugeValue, status)
-	}()
-
-	resp, err := e.client.Get(e.URI)
+	stats, err := e.client.Stats()
 	if err != nil {
-		log.Error("Error while querying Bind: ", err)
+		ch <- prometheus.MustNewConstMetric(up, prometheus.GaugeValue, 0)
+		log.Error("Couldn't retrieve BIND stats: ", err)
 		return
 	}
-	defer resp.Body.Close()
+	ch <- prometheus.MustNewConstMetric(up, prometheus.GaugeValue, 1)
 
-	body, err := ioutil.ReadAll(resp.Body)
-	if err != nil {
-		log.Error("Failed to read XML response body: ", err)
-		return
-	}
-
-	status = 1
-
-	root := Isc{}
-	if err := xml.Unmarshal([]byte(body), &root); err != nil {
-		log.Error("Failed to unmarshal XML response: ", err)
-		return
-	}
-
-	stats := root.Bind.Statistics
-	for _, s := range stats.Server.QueriesIn.Rdtype {
+	// Server statistics.
+	for _, s := range stats.Server.IncomingQueries {
 		ch <- prometheus.MustNewConstMetric(
 			incomingQueries, prometheus.CounterValue, float64(s.Counter), s.Name,
 		)
 	}
-	for _, s := range stats.Server.Requests.Opcode {
+	for _, s := range stats.Server.IncomingRequests {
 		ch <- prometheus.MustNewConstMetric(
 			incomingRequests, prometheus.CounterValue, float64(s.Counter), s.Name,
 		)
 	}
-
-	for _, s := range stats.Server.NsStats {
+	for _, s := range stats.Server.NSStats {
 		if desc, ok := serverLabelStats[s.Name]; ok {
 			r := strings.TrimPrefix(s.Name, "Qry")
 			ch <- prometheus.MustNewConstMetric(
@@ -243,20 +210,19 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 		}
 	}
 
+	// View statistics.
 	for _, v := range stats.Views {
 		for _, s := range v.Cache {
 			ch <- prometheus.MustNewConstMetric(
 				resolverCache, prometheus.GaugeValue, float64(s.Counter), v.Name, s.Name,
 			)
 		}
-
-		for _, s := range v.Rdtype {
+		for _, s := range v.ResolverQueries {
 			ch <- prometheus.MustNewConstMetric(
 				resolverQueries, prometheus.CounterValue, float64(s.Counter), v.Name, s.Name,
 			)
 		}
-
-		for _, s := range v.Resstat {
+		for _, s := range v.ResolverStats {
 			if desc, ok := resolverMetricStats[s.Name]; ok {
 				ch <- prometheus.MustNewConstMetric(
 					desc, prometheus.CounterValue, float64(s.Counter), v.Name,
@@ -268,8 +234,7 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 				)
 			}
 		}
-
-		if buckets, count, err := histogram(v.Resstat); err == nil {
+		if buckets, count, err := histogram(v.ResolverStats); err == nil {
 			ch <- prometheus.MustNewConstHistogram(
 				resolverQueryDuration, count, math.NaN(), buckets, v.Name,
 			)
@@ -277,26 +242,27 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 			log.Warn("Error parsing RTT:", err)
 		}
 	}
-	threadModel := stats.Taskmgr.ThreadModel
+
+	// TaskManager statistics.
+	threadModel := stats.TaskManager.ThreadModel
 	ch <- prometheus.MustNewConstMetric(
 		tasksRunning, prometheus.GaugeValue, float64(threadModel.TasksRunning),
 	)
 	ch <- prometheus.MustNewConstMetric(
 		workerThreads, prometheus.GaugeValue, float64(threadModel.WorkerThreads),
 	)
-
 }
 
-func histogram(stats []Stat) (map[float64]uint64, uint64, error) {
+func histogram(stats []bind.Stat) (map[float64]uint64, uint64, error) {
 	buckets := map[float64]uint64{}
 	var count uint64
 
 	for _, s := range stats {
-		if strings.HasPrefix(s.Name, qryRTT) {
+		if strings.HasPrefix(s.Name, bind.QryRTT) {
 			b := math.Inf(0)
 			if !strings.HasSuffix(s.Name, "+") {
 				var err error
-				rrt := strings.TrimPrefix(s.Name, qryRTT)
+				rrt := strings.TrimPrefix(s.Name, bind.QryRTT)
 				b, err = strconv.ParseFloat(rrt, 32)
 				if err != nil {
 					return buckets, 0, fmt.Errorf("could not parse RTT: %s", rrt)

bind_exporter_test.go

@@ -14,17 +14,31 @@ import (
 func TestBindExporter(t *testing.T) {
 	tests := []string{
 		`bind_up 1`,
-		`bind_incoming_queries_total{type="A"} 100`,
-		`bind_incoming_requests_total{name="QUERY"} 100`,
-		`bind_responses_total{result="Success"} 100`,
+		`bind_incoming_queries_total{type="A"} 128417`,
+		`bind_incoming_requests_total{opcode="QUERY"} 37634`,
+		`bind_responses_total{result="Success"} 29313`,
+		`bind_query_errors_total{error="Dropped"} 237`,
+		`bind_query_errors_total{error="Duplicate"} 216`,
+		`bind_query_errors_total{error="Failure"} 2950`,
+		`bind_resolver_cache_rrsets{type="A",view="_default"} 34324`,
+		`bind_resolver_queries_total{type="CNAME",view="_default"} 28`,
 		`bind_resolver_response_errors_total{error="FORMERR",view="_bind"} 0`,
-		`bind_resolver_response_errors_total{error="FORMERR",view="_default"} 0`,
+		`bind_resolver_response_errors_total{error="FORMERR",view="_default"} 42906`,
 		`bind_resolver_response_errors_total{error="NXDOMAIN",view="_bind"} 0`,
-		`bind_resolver_response_errors_total{error="NXDOMAIN",view="_default"} 0`,
+		`bind_resolver_response_errors_total{error="NXDOMAIN",view="_default"} 16707`,
 		`bind_resolver_response_errors_total{error="OtherError",view="_bind"} 0`,
-		`bind_resolver_response_errors_total{error="OtherError",view="_default"} 0`,
+		`bind_resolver_response_errors_total{error="OtherError",view="_default"} 20660`,
 		`bind_resolver_response_errors_total{error="SERVFAIL",view="_bind"} 0`,
-		`bind_resolver_response_errors_total{error="SERVFAIL",view="_default"} 0`,
+		`bind_resolver_response_errors_total{error="SERVFAIL",view="_default"} 7596`,
+		`bind_resolver_response_lame_total{view="_default"} 9108`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="0.01"} 38334`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="0.1"} 113122`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="0.5"} 182658`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="0.8"} 187375`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="1.6"} 188409`,
+		`bind_resolver_query_duration_seconds_bucket{view="_default",le="+Inf"} 227755`,
+		`bind_tasks_running 8`,
+		`bind_worker_threads 16`,
 	}
 
 	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
@@ -39,7 +53,7 @@ func TestBindExporter(t *testing.T) {
 
 	for _, test := range tests {
 		if !bytes.Contains(o, []byte(test)) {
-			t.Errorf("expected to find %q", string(test))
+			t.Errorf("expected to find %q in output:\n%s", string(test), string(o))
 		}
 	}
 }