Add powerdns input plugin

closes #614

CHANGELOG.md

@@ -7,6 +7,7 @@
 - [#564](https://github.com/influxdata/telegraf/issues/564): features for plugin writing simplification. Internal metric data type.
 - [#603](https://github.com/influxdata/telegraf/pull/603): Aggregate statsd timing measurements into fields. Thanks @marcinbunsch!
 - [#601](https://github.com/influxdata/telegraf/issues/601): Warn when overwriting cached metrics.
+- [#614](https://github.com/influxdata/telegraf/pull/614): PowerDNS input plugin. Thanks @Kasen!
 
 ### Bugfixes
 - [#595](https://github.com/influxdata/telegraf/issues/595): graphite output should include tags to separate duplicate measurements.

README.md

@@ -165,6 +165,7 @@ Currently implemented sources:
 * phusion passenger
 * ping
 * postgresql
+* powerdns
 * procstat
 * prometheus
 * puppetagent

plugins/inputs/all/all.go

@@ -26,6 +26,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/inputs/phpfpm"
 	_ "github.com/influxdata/telegraf/plugins/inputs/ping"
 	_ "github.com/influxdata/telegraf/plugins/inputs/postgresql"
+	_ "github.com/influxdata/telegraf/plugins/inputs/powerdns"
 	_ "github.com/influxdata/telegraf/plugins/inputs/procstat"
 	_ "github.com/influxdata/telegraf/plugins/inputs/prometheus"
 	_ "github.com/influxdata/telegraf/plugins/inputs/puppetagent"

plugins/inputs/powerdns/README.md

+# PowerDNS Input Plugin
+
+The powerdns plugin gathers metrics about PowerDNS using unix socket.
+
+### Configuration:
+
+```
+# Description
+[[inputs.powerdns]]
+  # An array of sockets to gather stats about.
+  # Specify a path to unix socket.
+  #
+  # If no servers are specified, then '/var/run/pdns.controlsocket' is used as the path.
+  unix_sockets = ["/var/run/pdns.controlsocket"]
+```
+
+### Measurements & Fields:
+
+- powerdns
+  - corrupt-packets
+  - deferred-cache-inserts
+  - deferred-cache-lookup
+  - dnsupdate-answers
+  - dnsupdate-changes
+  - dnsupdate-queries
+  - dnsupdate-refused
+  - packetcache-hit
+  - packetcache-miss
+  - packetcache-size
+  - query-cache-hit
+  - query-cache-miss
+  - rd-queries
+  - recursing-answers
+  - recursing-questions
+  - recursion-unanswered
+  - security-status
+  - servfail-packets
+  - signatures
+  - tcp-answers
+  - tcp-queries
+  - timedout-packets
+  - udp-answers
+  - udp-answers-bytes
+  - udp-do-queries
+  - udp-queries
+  - udp4-answers
+  - udp4-queries
+  - udp6-answers
+  - udp6-queries
+  - key-cache-size
+  - latency
+  - meta-cache-size
+  - qsize-q
+  - signature-cache-size
+  - sys-msec
+  - uptime
+  - user-msec
+
+### Tags:
+
+- tags: `server=socket`
+
+### Example Output:
+
+```
+$ ./telegraf -config telegraf.conf -input-filter powerdns -test
+> powerdns,server=/var/run/pdns.controlsocket corrupt-packets=0i,deferred-cache-inserts=0i,deferred-cache-lookup=0i,dnsupdate-answers=0i,dnsupdate-changes=0i,dnsupdate-queries=0i,dnsupdate-refused=0i,key-cache-size=0i,latency=26i,meta-cache-size=0i,packetcache-hit=0i,packetcache-miss=1i,packetcache-size=0i,qsize-q=0i,query-cache-hit=0i,query-cache-miss=6i,rd-queries=1i,recursing-answers=0i,recursing-questions=0i,recursion-unanswered=0i,security-status=3i,servfail-packets=0i,signature-cache-size=0i,signatures=0i,sys-msec=4349i,tcp-answers=0i,tcp-queries=0i,timedout-packets=0i,udp-answers=1i,udp-answers-bytes=50i,udp-do-queries=0i,udp-queries=0i,udp4-answers=1i,udp4-queries=1i,udp6-answers=0i,udp6-queries=0i,uptime=166738i,user-msec=3036i 1454078624932715706
+```

plugins/inputs/powerdns/powerdns.go

+package powerdns
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"net"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/inputs"
+)
+
+type Powerdns struct {
+	UnixSockets []string
+}
+
+var sampleConfig = `
+  # An array of sockets to gather stats about.
+  # Specify a path to unix socket.
+  #
+  # If no servers are specified, then '/var/run/pdns.controlsocket' is used as the path.
+  unix_sockets = ["/var/run/pdns.controlsocket"]
+`
+
+var defaultTimeout = 5 * time.Second
+
+func (p *Powerdns) SampleConfig() string {
+	return sampleConfig
+}
+
+func (p *Powerdns) Description() string {
+	return "Read metrics from one or many PowerDNS servers"
+}
+
+func (p *Powerdns) Gather(acc telegraf.Accumulator) error {
+	if len(p.UnixSockets) == 0 {
+		return p.gatherServer("/var/run/pdns.controlsocket", acc)
+	}
+
+	for _, serverSocket := range p.UnixSockets {
+		if err := p.gatherServer(serverSocket, acc); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func (p *Powerdns) gatherServer(address string, acc telegraf.Accumulator) error {
+	conn, err := net.DialTimeout("unix", address, defaultTimeout)
+	if err != nil {
+		return err
+	}
+
+	defer conn.Close()
+
+	conn.SetDeadline(time.Now().Add(defaultTimeout))
+
+	// Read and write buffer
+	rw := bufio.NewReadWriter(bufio.NewReader(conn), bufio.NewWriter(conn))
+
+	// Send command
+	if _, err := fmt.Fprint(conn, "show * \n"); err != nil {
+		return nil
+	}
+	if err := rw.Flush(); err != nil {
+		return err
+	}
+
+	// Read data
+	buf := make([]byte, 0, 4096)
+	tmp := make([]byte, 1024)
+	for {
+		n, err := rw.Read(tmp)
+		if err != nil {
+			if err != io.EOF {
+				return err
+			}
+
+			break
+		}
+		buf = append(buf, tmp[:n]...)
+	}
+
+	metrics := string(buf)
+
+	// Process data
+	fields, err := parseResponse(metrics)
+	if err != nil {
+		return err
+	}
+
+	// Add server socket as a tag
+	tags := map[string]string{"server": address}
+
+	acc.AddFields("powerdns", fields, tags)
+
+	return nil
+}
+
+func parseResponse(metrics string) (map[string]interface{}, error) {
+	values := make(map[string]interface{})
+
+	s := strings.Split(metrics, ",")
+
+	for _, metric := range s[:len(s)-1] {
+		m := strings.Split(metric, "=")
+
+		i, err := strconv.ParseInt(m[1], 10, 64)
+		if err != nil {
+			return values, err
+		}
+		values[m[0]] = i
+	}
+
+	return values, nil
+}
+
+func init() {
+	inputs.Add("powerdns", func() telegraf.Input {
+		return &Powerdns{}
+	})
+}

plugins/inputs/powerdns/powerdns_test.go

+package powerdns
+
+import (
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"net"
+	"testing"
+
+	"github.com/influxdata/telegraf/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+type statServer struct{}
+
+var metrics = "corrupt-packets=0,deferred-cache-inserts=0,deferred-cache-lookup=0," +
+	"dnsupdate-answers=0,dnsupdate-changes=0,dnsupdate-queries=0," +
+	"dnsupdate-refused=0,packetcache-hit=0,packetcache-miss=1,packetcache-size=0," +
+	"query-cache-hit=0,query-cache-miss=6,rd-queries=1,recursing-answers=0," +
+	"recursing-questions=0,recursion-unanswered=0,security-status=3," +
+	"servfail-packets=0,signatures=0,tcp-answers=0,tcp-queries=0," +
+	"timedout-packets=0,udp-answers=1,udp-answers-bytes=50,udp-do-queries=0," +
+	"udp-queries=0,udp4-answers=1,udp4-queries=1,udp6-answers=0,udp6-queries=0," +
+	"key-cache-size=0,latency=26,meta-cache-size=0,qsize-q=0," +
+	"signature-cache-size=0,sys-msec=2889,uptime=86317,user-msec=2167,"
+
+func (s statServer) serverSocket(l net.Listener) {
+
+	for {
+		conn, err := l.Accept()
+		if err != nil {
+			return
+		}
+
+		go func(c net.Conn) {
+			buf := make([]byte, 1024)
+			n, _ := c.Read(buf)
+
+			data := buf[:n]
+			if string(data) == "show * \n" {
+				c.Write([]byte(metrics))
+				c.Close()
+			}
+		}(conn)
+	}
+}
+
+func TestMemcachedGeneratesMetrics(t *testing.T) {
+	// We create a fake server to return test data
+	var randomNumber int64
+	binary.Read(rand.Reader, binary.LittleEndian, &randomNumber)
+	socket, err := net.Listen("unix", fmt.Sprintf("/tmp/pdns%d.controlsocket", randomNumber))
+	if err != nil {
+		t.Fatal("Cannot initalize server on port ")
+	}
+
+	defer socket.Close()
+
+	s := statServer{}
+	go s.serverSocket(socket)
+
+	p := &Powerdns{
+		UnixSockets: []string{fmt.Sprintf("/tmp/pdns%d.controlsocket", randomNumber)},
+	}
+
+	var acc testutil.Accumulator
+
+	err = p.Gather(&acc)
+	require.NoError(t, err)
+
+	intMetrics := []string{"corrupt-packets", "deferred-cache-inserts",
+		"deferred-cache-lookup", "dnsupdate-answers", "dnsupdate-changes",
+		"dnsupdate-queries", "dnsupdate-refused", "packetcache-hit",
+		"packetcache-miss", "packetcache-size", "query-cache-hit", "query-cache-miss",
+		"rd-queries", "recursing-answers", "recursing-questions",
+		"recursion-unanswered", "security-status", "servfail-packets", "signatures",
+		"tcp-answers", "tcp-queries", "timedout-packets", "udp-answers",
+		"udp-answers-bytes", "udp-do-queries", "udp-queries", "udp4-answers",
+		"udp4-queries", "udp6-answers", "udp6-queries", "key-cache-size", "latency",
+		"meta-cache-size", "qsize-q", "signature-cache-size", "sys-msec", "uptime", "user-msec"}
+
+	for _, metric := range intMetrics {
+		assert.True(t, acc.HasIntField("powerdns", metric), metric)
+	}
+}
+
+func TestPowerdnsParseMetrics(t *testing.T) {
+	values, err := parseResponse(metrics)
+	require.NoError(t, err, "Error parsing memcached response")
+
+	tests := []struct {
+		key   string
+		value int64
+	}{
+		{"corrupt-packets", 0},
+		{"deferred-cache-inserts", 0},
+		{"deferred-cache-lookup", 0},
+		{"dnsupdate-answers", 0},
+		{"dnsupdate-changes", 0},
+		{"dnsupdate-queries", 0},
+		{"dnsupdate-refused", 0},
+		{"packetcache-hit", 0},
+		{"packetcache-miss", 1},
+		{"packetcache-size", 0},
+		{"query-cache-hit", 0},
+		{"query-cache-miss", 6},
+		{"rd-queries", 1},
+		{"recursing-answers", 0},
+		{"recursing-questions", 0},
+		{"recursion-unanswered", 0},
+		{"security-status", 3},
+		{"servfail-packets", 0},
+		{"signatures", 0},
+		{"tcp-answers", 0},
+		{"tcp-queries", 0},
+		{"timedout-packets", 0},
+		{"udp-answers", 1},
+		{"udp-answers-bytes", 50},
+		{"udp-do-queries", 0},
+		{"udp-queries", 0},
+		{"udp4-answers", 1},
+		{"udp4-queries", 1},
+		{"udp6-answers", 0},
+		{"udp6-queries", 0},
+		{"key-cache-size", 0},
+		{"latency", 26},
+		{"meta-cache-size", 0},
+		{"qsize-q", 0},
+		{"signature-cache-size", 0},
+		{"sys-msec", 2889},
+		{"uptime", 86317},
+		{"user-msec", 2167},
+	}
+
+	for _, test := range tests {
+		value, ok := values[test.key]
+		if !ok {
+			t.Errorf("Did not find key for metric %s in values", test.key)
+			continue
+		}
+		if value != test.value {
+			t.Errorf("Metric: %s, Expected: %d, actual: %d",
+				test.key, test.value, value)
+		}
+	}
+}