Add disable_http2 field for HTTP client components (#169)

Fixes #117

Signed-off-by: Mihai Todor <[email protected]>

CHANGELOG.md

@@ -9,6 +9,7 @@ All notable changes to this project will be documented in this file.
 
 - A `crash` processor for FATAL logging. (@rockwotj)
 - A `uuid_v7` bloblang function. (@rockwotj)
+- Field `disable_http2` added to the `http_client` input and output and to the `http` processor. (@mihaitodor)
 
 ## 4.43.0 - 2025-01-13
 

internal/httpclient/client.go

@@ -5,6 +5,7 @@ package httpclient
 import (
 	"bytes"
 	"context"
+	"crypto/tls"
 	"errors"
 	"fmt"
 	"io"
@@ -120,6 +121,12 @@ func NewClientFromOldConfig(conf OldConfig, mgr *service.Resources, opts ...Requ
 		return nil, fmt.Errorf("failed to config logger for request dump: %v", err)
 	}
 
+	if conf.DisableHTTP2 {
+		if c, ok := h.client.Transport.(*http.Transport); ok {
+			c.TLSNextProto = map[string]func(string, *tls.Conn) http.RoundTripper{}
+		}
+	}
+
 	h.client = conf.clientCtor(h.clientCtx, h.client)
 
 	for _, c := range conf.BackoffOn {

internal/httpclient/client_test.go

@@ -828,3 +828,59 @@ extract_headers:
 	require.True(t, ok)
 	require.Equal(t, "https://example.com", location)
 }
+
+func TestHTTPClientDisableHTTP2(t *testing.T) {
+	tests := []struct {
+		name         string
+		disableHTTP2 bool
+		expProtocol  string
+	}{
+		{
+			name:        "http2 enabled",
+			expProtocol: "HTTP/2.0",
+		},
+		{
+			name:         "http2 disabled",
+			disableHTTP2: true,
+			expProtocol:  "HTTP/1.1",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			ts := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				assert.Equal(t, test.expProtocol, r.Proto)
+				b, err := io.ReadAll(r.Body)
+				require.NoError(t, err)
+				_, _ = w.Write(b)
+			}))
+			defer ts.Close()
+
+			ts.EnableHTTP2 = true
+
+			ts.StartTLS()
+
+			conf := clientConfig(t, `
+url: %s
+disable_http2: %t
+tls:
+  enabled: true
+  skip_cert_verify: true
+`, ts.URL, test.disableHTTP2)
+
+			h, err := NewClientFromOldConfig(conf, service.MockResources())
+			require.NoError(t, err)
+
+			dummyMsg := "hello world"
+			resBatch, err := h.Send(context.Background(), service.MessageBatch{
+				service.NewMessage([]byte(dummyMsg)),
+			})
+			require.NoError(t, err)
+			require.Len(t, resBatch, 1)
+
+			mBytes, err := resBatch[0].AsBytes()
+			require.NoError(t, err)
+			assert.Equal(t, dummyMsg, string(mBytes))
+		})
+	}
+}

internal/httpclient/config.go

@@ -30,6 +30,7 @@ const (
 	hcFieldDumpRequestLogLevel = "dump_request_log_level"
 	hcFieldTLS                 = "tls"
 	hcFieldProxyURL            = "proxy_url"
+	hcFieldDisableHTTP2        = "disable_http2"
 )
 
 // ConfigField returns a public API config field spec for an HTTP component,
@@ -108,6 +109,11 @@ func ConfigField(defaultVerb string, forOutput bool, extraChildren ...*service.C
 			Description("An optional HTTP proxy URL.").
 			Advanced().
 			Optional(),
+		service.NewBoolField(hcFieldDisableHTTP2).
+			Description("Whether or not to disable disable HTTP/2").
+			Advanced().
+			Default(false).
+			Version("4.44.0"),
 	)
 
 	innerFields = append(innerFields, extraChildren...)
@@ -167,6 +173,9 @@ func ConfigFromParsed(pConf *service.ParsedConfig) (conf OldConfig, err error) {
 	if conf.authSigner, err = pConf.HTTPRequestAuthSignerFromParsed(); err != nil {
 		return
 	}
+	if conf.DisableHTTP2, err = pConf.FieldBool(hcFieldDisableHTTP2); err != nil {
+		return
+	}
 	if conf.clientCtor, err = oauth2ClientCtorFromParsed(pConf); err != nil {
 		return
 	}
@@ -193,6 +202,7 @@ type OldConfig struct {
 	TLSEnabled          bool
 	TLSConf             *tls.Config
 	ProxyURL            string
+	DisableHTTP2        bool
 	authSigner          func(f fs.FS, req *http.Request) error
 	clientCtor          func(context.Context, *http.Client) *http.Client
 }