renaming plugins -> inputs

plugins/inputs/twemproxy/twemproxy.go

@@ -0,0 +1,149 @@
+package twemproxy
+
+import (
+	"encoding/json"
+	"errors"
+	"io/ioutil"
+	"net"
+	"time"
+
+	"github.com/influxdb/telegraf/plugins/inputs"
+)
+
+type Twemproxy struct {
+	Addr  string
+	Pools []string
+}
+
+var sampleConfig = `
+  # Twemproxy stats address and port (no scheme)
+  addr = "localhost:22222"
+  # Monitor pool name
+  pools = ["redis_pool", "mc_pool"]
+`
+
+func (t *Twemproxy) SampleConfig() string {
+	return sampleConfig
+}
+
+func (t *Twemproxy) Description() string {
+	return "Read Twemproxy stats data"
+}
+
+// Gather data from all Twemproxy instances
+func (t *Twemproxy) Gather(acc inputs.Accumulator) error {
+	conn, err := net.DialTimeout("tcp", t.Addr, 1*time.Second)
+	if err != nil {
+		return err
+	}
+	body, err := ioutil.ReadAll(conn)
+	if err != nil {
+		return err
+	}
+
+	var stats map[string]interface{}
+	if err = json.Unmarshal(body, &stats); err != nil {
+		return errors.New("Error decoding JSON response")
+	}
+
+	tags := make(map[string]string)
+	tags["twemproxy"] = t.Addr
+	t.processStat(acc, tags, stats)
+
+	return nil
+}
+
+// Process Twemproxy server stats
+func (t *Twemproxy) processStat(
+	acc inputs.Accumulator,
+	tags map[string]string,
+	data map[string]interface{},
+) {
+	if source, ok := data["source"]; ok {
+		if val, ok := source.(string); ok {
+			tags["source"] = val
+		}
+	}
+
+	fields := make(map[string]interface{})
+	metrics := []string{"total_connections", "curr_connections", "timestamp"}
+	for _, m := range metrics {
+		if value, ok := data[m]; ok {
+			if val, ok := value.(float64); ok {
+				fields[m] = val
+			}
+		}
+	}
+	acc.AddFields("twemproxy", fields, tags)
+
+	for _, pool := range t.Pools {
+		if poolStat, ok := data[pool]; ok {
+			if data, ok := poolStat.(map[string]interface{}); ok {
+				poolTags := copyTags(tags)
+				poolTags["pool"] = pool
+				t.processPool(acc, poolTags, data)
+			}
+		}
+	}
+}
+
+// Process pool data in Twemproxy stats
+func (t *Twemproxy) processPool(
+	acc inputs.Accumulator,
+	tags map[string]string,
+	data map[string]interface{},
+) {
+	serverTags := make(map[string]map[string]string)
+
+	fields := make(map[string]interface{})
+	for key, value := range data {
+		switch key {
+		case "client_connections", "forward_error", "client_err", "server_ejects", "fragments", "client_eof":
+			if val, ok := value.(float64); ok {
+				fields[key] = val
+			}
+		default:
+			if data, ok := value.(map[string]interface{}); ok {
+				if _, ok := serverTags[key]; !ok {
+					serverTags[key] = copyTags(tags)
+					serverTags[key]["server"] = key
+				}
+				t.processServer(acc, serverTags[key], data)
+			}
+		}
+	}
+	acc.AddFields("twemproxy_pool", fields, tags)
+}
+
+// Process backend server(redis/memcached) stats
+func (t *Twemproxy) processServer(
+	acc inputs.Accumulator,
+	tags map[string]string,
+	data map[string]interface{},
+) {
+	fields := make(map[string]interface{})
+	for key, value := range data {
+		switch key {
+		default:
+			if val, ok := value.(float64); ok {
+				fields[key] = val
+			}
+		}
+	}
+	acc.AddFields("twemproxy_pool_server", fields, tags)
+}
+
+// Tags is not expected to be mutated after passing to Add.
+func copyTags(tags map[string]string) map[string]string {
+	newTags := make(map[string]string)
+	for k, v := range tags {
+		newTags[k] = v
+	}
+	return newTags
+}
+
+func init() {
+	inputs.Add("twemproxy", func() inputs.Input {
+		return &Twemproxy{}
+	})
+}