Add ServiceNow serializer (#4809)

plugins/serializers/nowmetric/nowmetric.go

@@ -0,0 +1,137 @@
+package nowmetric
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"time"
+
+	"github.com/influxdata/telegraf"
+)
+
+type serializer struct {
+	TimestampUnits time.Duration
+}
+
+/*
+Example for the JSON generated and pushed to the MID
+{
+	"metric_type":"cpu_usage_system",
+	"resource":"",
+	"node":"ASGARD",
+	"value": 0.89,
+	"timestamp":1487365430,
+	"ci2metric_id":{"node":"ASGARD"},
+	"source":"Telegraf"
+}
+*/
+
+type OIMetric struct {
+	Metric    string            `json:"metric_type"`
+	Resource  string            `json:"resource"`
+	Node      string            `json:"node"`
+	Value     interface{}       `json:"value"`
+	Timestamp int64             `json:"timestamp"`
+	CiMapping map[string]string `json:"ci2metric_id"`
+	Source    string            `json:"source"`
+}
+
+type OIMetrics []OIMetric
+
+func NewSerializer() (*serializer, error) {
+	s := &serializer{}
+	return s, nil
+}
+
+func (s *serializer) Serialize(metric telegraf.Metric) (out []byte, err error) {
+	serialized, err := s.createObject(metric)
+	if err != nil {
+		return []byte{}, nil
+	}
+	return serialized, err
+}
+
+func (s *serializer) SerializeBatch(metrics []telegraf.Metric) (out []byte, err error) {
+	objects := make([]byte, 0)
+	for _, metric := range metrics {
+		m, err := s.createObject(metric)
+		if err != nil {
+			return nil, fmt.Errorf("D! [serializer.nowmetric] Dropping invalid metric: %s", metric.Name())
+		} else if m != nil {
+			objects = append(objects, m...)
+		}
+	}
+	replaced := bytes.Replace(objects, []byte("]["), []byte(","), -1)
+	return replaced, nil
+}
+
+func (s *serializer) createObject(metric telegraf.Metric) ([]byte, error) {
+	/*  ServiceNow Operational Intelligence supports an array of JSON objects.
+	** Following elements accepted in the request body:
+		 ** metric_type: 	The name of the metric
+		 ** resource:   	Information about the resource for which metric data is being collected. In the example below, C:\ is the resource for which metric data is collected
+		 ** node:       	IP, FQDN, name of the CI, or host
+		 ** value:      	Value of the metric
+		 ** timestamp: 		Epoch timestamp of the metric in milliseconds
+		 ** ci2metric_id:	List of key-value pairs to identify the CI.
+		 ** source:			Data source monitoring the metric type
+	*/
+	var allmetrics OIMetrics
+	var oimetric OIMetric
+
+	oimetric.Source = "Telegraf"
+
+	// Process Tags to extract node & resource name info
+	for _, tag := range metric.TagList() {
+		if tag.Key == "" || tag.Value == "" {
+			continue
+		}
+
+		if tag.Key == "objectname" {
+			oimetric.Resource = tag.Value
+		}
+
+		if tag.Key == "host" {
+			oimetric.Node = tag.Value
+		}
+	}
+
+	// Format timestamp to UNIX epoch
+	oimetric.Timestamp = (metric.Time().UnixNano() / int64(time.Millisecond))
+
+	// Loop of fields value pair and build datapoint for each of them
+	for _, field := range metric.FieldList() {
+		if !verifyValue(field.Value) {
+			// Ignore String
+			continue
+		}
+
+		if field.Key == "" {
+			// Ignore Empty Key
+			continue
+		}
+
+		oimetric.Metric = field.Key
+		oimetric.Value = field.Value
+
+		if oimetric.Node != "" {
+			cimapping := map[string]string{}
+			cimapping["node"] = oimetric.Node
+			oimetric.CiMapping = cimapping
+		}
+
+		allmetrics = append(allmetrics, oimetric)
+	}
+
+	metricsJson, err := json.Marshal(allmetrics)
+
+	return metricsJson, err
+}
+
+func verifyValue(v interface{}) bool {
+	switch v.(type) {
+	case string:
+		return false
+	}
+	return true
+}