Add support for sending a request body to http input (#5074)

plugins/inputs/http/README.md

@@ -19,6 +19,13 @@ The HTTP input plugin collects metrics from one or more HTTP(S) endpoints.  The
   ## Optional HTTP headers
   # headers = {"X-Special-Header" = "Special-Value"}
 
+  ## HTTP entity-body to send with POST/PUT requests.
+  # body = ""
+
+  ## HTTP Content-Encoding for write request body, can be set to "gzip" to
+  ## compress body or "identity" to apply no encoding.
+  # content_encoding = "identity"
+
   ## Optional HTTP Basic Auth Credentials
   # username = "username"
   # password = "pa$$word"

plugins/inputs/http/http.go

@@ -3,6 +3,7 @@ package http
 import (
 	"errors"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"strings"
@@ -18,16 +19,18 @@ import (
 
 type HTTP struct {
 	URLs            []string `toml:"urls"`
-	Method string
+	Method          string   `toml:"method"`
+	Body            string   `toml:"body"`
+	ContentEncoding string   `toml:"content_encoding"`
 
-	Headers map[string]string
+	Headers map[string]string `toml:"headers"`
 
 	// HTTP Basic Auth Credentials
-	Username string
+	Username string `toml:"username"`
-	Password string
+	Password string `toml:"password"`
 	tls.ClientConfig
 
-	Timeout internal.Duration
+	Timeout internal.Duration `toml:"timeout"`
 
 	client *http.Client
 
@@ -52,6 +55,13 @@ var sampleConfig = `
   # username = "username"
   # password = "pa$$word"
 
+  ## HTTP entity-body to send with POST/PUT requests.
+  # body = ""
+
+  ## HTTP Content-Encoding for write request body, can be set to "gzip" to
+  ## compress body or "identity" to apply no encoding.
+  # content_encoding = "identity"
+
   ## Optional TLS Config
   # tls_ca = "/etc/telegraf/ca.pem"
   # tls_cert = "/etc/telegraf/cert.pem"
@@ -132,11 +142,20 @@ func (h *HTTP) gatherURL(
 	acc telegraf.Accumulator,
 	url string,
 ) error {
-	request, err := http.NewRequest(h.Method, url, nil)
+	body, err := makeRequestBodyReader(h.ContentEncoding, h.Body)
 	if err != nil {
 		return err
 	}
 
+	request, err := http.NewRequest(h.Method, url, body)
+	if err != nil {
+		return err
+	}
+
+	if h.ContentEncoding == "gzip" {
+		request.Header.Set("Content-Encoding", "gzip")
+	}
+
 	for k, v := range h.Headers {
 		if strings.ToLower(k) == "host" {
 			request.Host = v
@@ -183,6 +202,18 @@ func (h *HTTP) gatherURL(
 	return nil
 }
 
+func makeRequestBodyReader(contentEncoding, body string) (io.Reader, error) {
+	var err error
+	var reader io.Reader = strings.NewReader(body)
+	if contentEncoding == "gzip" {
+		reader, err = internal.CompressWithGzip(reader)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return reader, nil
+}
+
 func init() {
 	inputs.Add("http", func() telegraf.Input {
 		return &HTTP{

plugins/inputs/http/http_test.go

@@ -1,6 +1,9 @@
 package http_test
 
 import (
+	"compress/gzip"
+	"fmt"
+	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -149,3 +152,93 @@ const simpleJSON = `
     "a": 1.2
 }
 `
+
+func TestBodyAndContentEncoding(t *testing.T) {
+	ts := httptest.NewServer(http.NotFoundHandler())
+	defer ts.Close()
+
+	url := fmt.Sprintf("http://%s", ts.Listener.Addr().String())
+
+	tests := []struct {
+		name             string
+		plugin           *plugin.HTTP
+		queryHandlerFunc func(t *testing.T, w http.ResponseWriter, r *http.Request)
+	}{
+		{
+			name: "no body",
+			plugin: &plugin.HTTP{
+				Method: "POST",
+				URLs:   []string{url},
+			},
+			queryHandlerFunc: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
+				body, err := ioutil.ReadAll(r.Body)
+				require.NoError(t, err)
+				require.Equal(t, []byte(""), body)
+				w.WriteHeader(http.StatusOK)
+			},
+		},
+		{
+			name: "post body",
+			plugin: &plugin.HTTP{
+				URLs:   []string{url},
+				Method: "POST",
+				Body:   "test",
+			},
+			queryHandlerFunc: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
+				body, err := ioutil.ReadAll(r.Body)
+				require.NoError(t, err)
+				require.Equal(t, []byte("test"), body)
+				w.WriteHeader(http.StatusOK)
+			},
+		},
+		{
+			name: "get method body is sent",
+			plugin: &plugin.HTTP{
+				URLs:   []string{url},
+				Method: "GET",
+				Body:   "test",
+			},
+			queryHandlerFunc: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
+				body, err := ioutil.ReadAll(r.Body)
+				require.NoError(t, err)
+				require.Equal(t, []byte("test"), body)
+				w.WriteHeader(http.StatusOK)
+			},
+		},
+		{
+			name: "gzip encoding",
+			plugin: &plugin.HTTP{
+				URLs:            []string{url},
+				Method:          "GET",
+				Body:            "test",
+				ContentEncoding: "gzip",
+			},
+			queryHandlerFunc: func(t *testing.T, w http.ResponseWriter, r *http.Request) {
+				require.Equal(t, r.Header.Get("Content-Encoding"), "gzip")
+
+				gr, err := gzip.NewReader(r.Body)
+				require.NoError(t, err)
+				body, err := ioutil.ReadAll(gr)
+				require.NoError(t, err)
+				require.Equal(t, []byte("test"), body)
+				w.WriteHeader(http.StatusOK)
+			},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			ts.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				tt.queryHandlerFunc(t, w, r)
+			})
+
+			parser, err := parsers.NewParser(&parsers.Config{DataFormat: "influx"})
+			require.NoError(t, err)
+
+			tt.plugin.SetParser(parser)
+
+			var acc testutil.Accumulator
+			err = tt.plugin.Gather(&acc)
+			require.NoError(t, err)
+		})
+	}
+}