Add JSON input support to zipkin plugin (#3150)

(cherry picked from commit 13a6b917c3)

plugins/inputs/zipkin/trace/trace.go

@@ -0,0 +1,41 @@
+package trace
+
+import (
+	"time"
+)
+
+// Trace is an array (or a series) of spans
+type Trace []Span
+
+//Span represents a specific zipkin span. It holds the majority of the same
+// data as a zipkin span sent via the thrift protocol, but is presented in a
+// format which is more straightforward for storage purposes.
+type Span struct {
+	ID                string
+	TraceID           string // zipkin traceid high concat with traceid
+	Name              string
+	ParentID          string
+	ServiceName       string
+	Timestamp         time.Time // If zipkin input is nil then time.Now()
+	Duration          time.Duration
+	Annotations       []Annotation
+	BinaryAnnotations []BinaryAnnotation
+}
+
+// BinaryAnnotation represents a zipkin binary annotation. It contains
+// all of the same fields as might be found in its zipkin counterpart.
+type BinaryAnnotation struct {
+	Key         string
+	Value       string
+	Host        string // annotation.endpoint.ipv4 + ":" + annotation.endpoint.port
+	ServiceName string
+}
+
+// Annotation represents an ordinary zipkin annotation. It contains the data fields
+// which will become fields/tags in influxdb
+type Annotation struct {
+	Timestamp   time.Time
+	Value       string
+	Host        string // annotation.endpoint.ipv4 + ":" + annotation.endpoint.port
+	ServiceName string
+}