Dynatrace output plugin (influxdata#7881)

.gitignore

@@ -1,3 +1,4 @@
+/.idea
 /build
 /telegraf
 /telegraf.exe

plugins/outputs/all/all.go

@@ -10,6 +10,7 @@ import (
 	_ "github.com/influxdata/telegraf/plugins/outputs/cratedb"
 	_ "github.com/influxdata/telegraf/plugins/outputs/datadog"
 	_ "github.com/influxdata/telegraf/plugins/outputs/discard"
+	_ "github.com/influxdata/telegraf/plugins/outputs/dynatrace"
 	_ "github.com/influxdata/telegraf/plugins/outputs/elasticsearch"
 	_ "github.com/influxdata/telegraf/plugins/outputs/exec"
 	_ "github.com/influxdata/telegraf/plugins/outputs/execd"

plugins/outputs/dynatrace/README.md

@@ -0,0 +1,24 @@
+# Dynatrace Output Plugin
+
+This plugin writes telegraf metrics to a Dynatrace environment. 
+
+An API token is necessary, which can be obtained in your Dynatrace environment. Navigate to **Dynatrace > Settings > Integration > Dynatrace API** and create a new token with 
+'Data ingest' access scope enabled. 
+
+Telegraf measurements which can't be converted to a float64 are skipped.
+
+Metrics fields are added to the measurement name by using '.' in the metric name. 
+
+### Configuration
+
+```toml
+[[outputs.dynatrace]]
+  ## Dynatrace environment URL (e.g.: https://YOUR_DOMAIN/api/v2/metrics/ingest) or use the local ingest endpoint of your OneAgent monitored host (e.g.: http://127.0.0.1:14499/metrics/ingest).
+  environmentURL = ""
+  environmentApiToken = ""
+  ## Optional prefix for metric names (e.g.: "telegraf.")
+  prefix = "telegraf."
+  ## Flag for skipping the tls certificate check, just for testing purposes, should be false by default
+  skipCertificateCheck = false
+
+```

plugins/outputs/dynatrace/dynatrace.go

@@ -0,0 +1,274 @@
+package dynatrace
+
+import (
+	"bytes"
+	"fmt"
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/internal"
+	"github.com/influxdata/telegraf/plugins/common/tls"
+	"github.com/influxdata/telegraf/plugins/outputs"
+	"io/ioutil"
+	"math"
+	"net/http"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"time"
+)
+
+const (
+	oneAgentMetricsUrl = "http://127.0.0.1:14499/metrics/ingest"
+)
+
+var (
+	reNameAllowedCharList = regexp.MustCompile("[^A-Za-z0-9.]+")
+	maxDimKeyLen          = 100
+	maxMetricKeyLen       = 250
+)
+
+// Dynatrace Configuration for the Dynatrace output plugin
+type Dynatrace struct {
+	URL                string            `toml:"url"`
+	APIToken           string            `toml:"api_token"`
+	InsecureSkipVerify bool              `toml:"insecure_skip_verify"`
+	Prefix             string            `toml:"prefix"`
+	Log                telegraf.Logger   `toml:"-"`
+	Timeout            internal.Duration `toml:"timeout"`
+
+	tls.ClientConfig
+
+	client *http.Client
+}
+
+const sampleConfig = `
+  ## For usage with the Dynatrace OneAgent you can omit any configuration,
+  ## the only requirement is that the OneAgent is running on the same host.
+  ## Only setup environment url and token if you want to monitor a Host without the OneAgent present.
+  ##
+  ## Your Dynatrace environment URL.
+  ## For Dynatrace OneAgent you can leave this empty or set it to "http://127.0.0.1:14499/metrics/ingest" (default)
+  ## For Dynatrace SaaS environments the URL scheme is "https://{your-environment-id}.live.dynatrace.com/api/v2/metrics/ingest"
+  ## For Dynatrace Managed environments the URL scheme is "https://{your-domain}/e/{your-environment-id}/api/v2/metrics/ingest"
+  url = ""
+
+  ## Your Dynatrace API token. 
+  ## Create an API token within your Dynatrace environment, by navigating to Settings > Integration > Dynatrace API
+  ## The API token needs data ingest scope permission. When using OneAgent, no API token is required.
+  api_token = "" 
+
+  ## Optional prefix for metric names (e.g.: "telegraf.")
+  prefix = "telegraf."
+
+  ## Optional TLS Config
+  # tls_ca = "/etc/telegraf/ca.pem"
+  # tls_cert = "/etc/telegraf/cert.pem"
+  # tls_key = "/etc/telegraf/key.pem"
+
+  ## Optional flag for ignoring tls certificate check
+  # insecure_skip_verify = false
+
+
+  ## Connection timeout, defaults to "5s" if not set.
+  timeout = "5s"
+`
+
+// Connect Connects the Dynatrace output plugin to the Telegraf stream
+func (d *Dynatrace) Connect() error {
+	return nil
+}
+
+// Close Closes the Dynatrace output plugin
+func (d *Dynatrace) Close() error {
+	d.client = nil
+	return nil
+}
+
+// SampleConfig Returns a sample configuration for the Dynatrace output plugin
+func (d *Dynatrace) SampleConfig() string {
+	return sampleConfig
+}
+
+// Description returns the description for the Dynatrace output plugin
+func (d *Dynatrace) Description() string {
+	return "Send telegraf metrics to a Dynatrace environment"
+}
+
+// Normalizes a metric keys or metric dimension identifiers
+// according to Dynatrace format.
+func (d *Dynatrace) normalize(s string, max int) (string, error) {
+	s = reNameAllowedCharList.ReplaceAllString(s, "_")
+
+	// Strip Digits and underscores if they are at the beginning of the string
+	normalizedString := strings.TrimLeft(s, "_0123456789")
+
+	for strings.HasPrefix(normalizedString, "_") {
+		normalizedString = normalizedString[1:]
+	}
+
+	if len(normalizedString) > max {
+		normalizedString = normalizedString[:max]
+	}
+
+	for strings.HasSuffix(normalizedString, "_") {
+		normalizedString = normalizedString[:len(normalizedString)-1]
+	}
+
+	if len(normalizedString) == 0 {
+		return "", fmt.Errorf("error normalizing the string: %s", s)
+	}
+	return normalizedString, nil
+}
+
+func (d *Dynatrace) escape(v string) string {
+	return strconv.Quote(v)
+}
+
+func (d *Dynatrace) Write(metrics []telegraf.Metric) error {
+	var buf bytes.Buffer
+	var tagb bytes.Buffer
+	if len(metrics) == 0 {
+		return nil
+	}
+
+	for _, metric := range metrics {
+		// first write the tags into a buffer
+		tagb.Reset()
+		if len(metric.Tags()) > 0 {
+			keys := make([]string, 0, len(metric.Tags()))
+			for k := range metric.Tags() {
+				keys = append(keys, k)
+			}
+			// sort tag keys to expect the same order in ech run
+			sort.Strings(keys)
+
+			for _, k := range keys {
+				tagKey, err := d.normalize(k, maxDimKeyLen)
+				if err != nil {
+					continue
+				}
+				fmt.Fprintf(&tagb, ",%s=%s", strings.ToLower(tagKey), d.escape(metric.Tags()[k]))
+
+			}
+		}
+		if len(metric.Fields()) > 0 {
+			for k, v := range metric.Fields() {
+				var value string
+				switch v := v.(type) {
+				case string:
+					continue
+				case float64:
+					if !math.IsNaN(v) && !math.IsInf(v, 0) {
+						value = fmt.Sprintf("%f", v)
+					} else {
+						continue
+					}
+				case uint64:
+					value = strconv.FormatUint(v, 10)
+				case int64:
+					value = strconv.FormatInt(v, 10)
+				case bool:
+					if v {
+						value = "1"
+					} else {
+						value = "0"
+					}
+				default:
+					d.Log.Debugf("Dynatrace type not supported! %s", v)
+					continue
+				}
+
+				// metric name
+				metricKey, err := d.normalize(k, maxMetricKeyLen)
+				if err != nil {
+					continue
+				}
+
+				metricID, err := d.normalize(d.Prefix+metric.Name()+"."+metricKey, maxMetricKeyLen)
+				// write metric name combined with its field
+				if err != nil {
+					continue
+				}
+				fmt.Fprintf(&buf, "%s", metricID)
+				// add the tag string
+				fmt.Fprintf(&buf, "%s", tagb.String())
+
+				// write measured value
+				fmt.Fprintf(&buf, " %v\n", value)
+			}
+		}
+	}
+
+	return d.send(buf.Bytes())
+}
+
+func (d *Dynatrace) send(msg []byte) error {
+	var err error
+	req, err := http.NewRequest("POST", d.URL, bytes.NewBuffer(msg))
+	if err != nil {
+		d.Log.Errorf("Dynatrace error: %s", err.Error())
+		return fmt.Errorf("Dynatrace error while creating HTTP request:, %s", err.Error())
+	}
+	req.Header.Add("Content-Type", "text/plain; charset=UTF-8")
+
+	if len(d.APIToken) != 0 {
+		req.Header.Add("Authorization", "Api-Token "+d.APIToken)
+	}
+	// add user-agent header to identify metric source
+	req.Header.Add("User-Agent", "telegraf")
+
+	resp, err := d.client.Do(req)
+	if err != nil {
+		d.Log.Errorf("Dynatrace error: %s", err.Error())
+		fmt.Println(req)
+		return fmt.Errorf("Dynatrace error while sending HTTP request:, %s", err.Error())
+	}
+	defer resp.Body.Close()
+
+	// print metric line results as info log
+	if resp.StatusCode == http.StatusOK || resp.StatusCode == http.StatusAccepted {
+		bodyBytes, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			d.Log.Errorf("Dynatrace error reading response")
+		}
+		bodyString := string(bodyBytes)
+		d.Log.Debugf("Dynatrace returned: %s", bodyString)
+	} else {
+		return fmt.Errorf("Dynatrace request failed with response code:, %d", resp.StatusCode)
+	}
+
+	return nil
+}
+
+func (d *Dynatrace) Init() error {
+	if len(d.URL) == 0 {
+		d.Log.Infof("Dynatrace URL is empty, defaulting to OneAgent metrics interface")
+		d.URL = oneAgentMetricsUrl
+	}
+	if d.URL != oneAgentMetricsUrl && len(d.APIToken) == 0 {
+		d.Log.Errorf("Dynatrace api_token is a required field for Dynatrace output")
+		return fmt.Errorf("api_token is a required field for Dynatrace output")
+	}
+
+	tlsCfg, err := d.ClientConfig.TLSConfig()
+	if err != nil {
+		return err
+	}
+
+	d.client = &http.Client{
+		Transport: &http.Transport{
+			Proxy:           http.ProxyFromEnvironment,
+			TLSClientConfig: tlsCfg,
+		},
+		Timeout: d.Timeout.Duration,
+	}
+	return nil
+}
+
+func init() {
+	outputs.Add("dynatrace", func() telegraf.Output {
+		return &Dynatrace{
+			Timeout: internal.Duration{Duration: time.Second * 5},
+		}
+	})
+}