Adds snappy support for http_listener_v2 (influxdata#8966)

plugins/inputs/http_listener_v2/http_listener_v2.go

@@ -12,6 +12,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/golang/snappy"
 	"github.com/influxdata/telegraf"
 	"github.com/influxdata/telegraf/internal"
 	tlsint "github.com/influxdata/telegraf/plugins/common/tls"
@@ -247,28 +248,50 @@ func (h *HTTPListenerV2) serveWrite(res http.ResponseWriter, req *http.Request)
 }
 
 func (h *HTTPListenerV2) collectBody(res http.ResponseWriter, req *http.Request) ([]byte, bool) {
-	body := req.Body
+	encoding := req.Header.Get("Content-Encoding")
 
-	// Handle gzip request bodies
-	if req.Header.Get("Content-Encoding") == "gzip" {
-		var err error
-		body, err = gzip.NewReader(req.Body)
+	switch encoding {
+	case "gzip":
+		r, err := gzip.NewReader(req.Body)
 		if err != nil {
 			h.Log.Debug(err.Error())
 			badRequest(res)
 			return nil, false
 		}
-		defer body.Close()
-	}
-
-	body = http.MaxBytesReader(res, body, h.MaxBodySize.Size)
-	bytes, err := ioutil.ReadAll(body)
-	if err != nil {
-		tooLarge(res)
-		return nil, false
+		defer r.Close()
+		maxReader := http.MaxBytesReader(res, r, h.MaxBodySize.Size)
+		bytes, err := ioutil.ReadAll(maxReader)
+		if err != nil {
+			tooLarge(res)
+			return nil, false
+		}
+		return bytes, true
+	case "snappy":
+		defer req.Body.Close()
+		bytes, err := ioutil.ReadAll(req.Body)
+		if err != nil {
+			h.Log.Debug(err.Error())
+			badRequest(res)
+			return nil, false
+		}
+		// snappy block format is only supported by decode/encode not snappy reader/writer
+		bytes, err = snappy.Decode(nil, bytes)
+		if err != nil {
+			h.Log.Debug(err.Error())
+			badRequest(res)
+			return nil, false
+		}
+		return bytes, true
+	default:
+		defer req.Body.Close()
+		bytes, err := ioutil.ReadAll(req.Body)
+		if err != nil {
+			h.Log.Debug(err.Error())
+			badRequest(res)
+			return nil, false
+		}
+		return bytes, true
 	}
-
-	return bytes, true
 }
 
 func (h *HTTPListenerV2) collectQuery(res http.ResponseWriter, req *http.Request) ([]byte, bool) {

plugins/inputs/http_listener_v2/http_listener_v2_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/golang/snappy"
 	"github.com/influxdata/telegraf/internal"
 	"github.com/influxdata/telegraf/plugins/parsers"
 	"github.com/influxdata/telegraf/testutil"
@@ -327,6 +328,44 @@ func TestWriteHTTPGzippedData(t *testing.T) {
 	}
 }
 
+// test that writing snappy data works
+func TestWriteHTTPSnappyData(t *testing.T) {
+	listener := newTestHTTPListenerV2()
+
+	acc := &testutil.Accumulator{}
+	require.NoError(t, listener.Start(acc))
+	defer listener.Stop()
+
+	testData := "cpu_load_short,host=server01 value=12.0 1422568543702900257\n"
+	encodedData := snappy.Encode(nil, []byte(testData))
+
+	req, err := http.NewRequest("POST", createURL(listener, "http", "/write", ""), bytes.NewBuffer(encodedData))
+	require.NoError(t, err)
+	req.Header.Set("Content-Encoding", "snappy")
+
+	client := &http.Client{}
+	resp, err := client.Do(req)
+	if err != nil {
+		t.Log("Test client request failed. Error: ", err)
+	}
+	err = resp.Body.Close()
+	if err != nil {
+		t.Log("Test client close failed. Error: ", err)
+	}
+	require.NoError(t, err)
+	require.EqualValues(t, 204, resp.StatusCode)
+
+	hostTags := []string{"server01"}
+	acc.Wait(1)
+
+	for _, hostTag := range hostTags {
+		acc.AssertContainsTaggedFields(t, "cpu_load_short",
+			map[string]interface{}{"value": float64(12)},
+			map[string]string{"host": hostTag},
+		)
+	}
+}
+
 // writes 25,000 metrics to the listener with 10 different writers
 func TestWriteHTTPHighTraffic(t *testing.T) {
 	if runtime.GOOS == "darwin" {