fix: support getBody in otelploghttp (#8096)

Based on #7931

Adding another `getBody` PR to the chain 😄.

This one is harder to catch if it's a problem since logs aren't being
sent in case of error.

---------

Signed-off-by: Toma Puljak <toma.puljak@hotmail.com>
Co-authored-by: Robert Pająk <pellared@hotmail.com>
Co-authored-by: Damien Mathieu <42@dmathieu.com>

Author: 3 people

CHANGELOG.md

@@ -35,6 +35,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Return spec-compliant `TraceIdRatioBased` description. This is a breaking behavioral change, but it is necessary to
   make the implementation [spec-compliant](https://opentelemetry.io/docs/specs/otel/trace/sdk/#traceidratiobased). (#8027)
 - Fix a race condition in `go.opentelemetry.io/otel/sdk/metric` where the lastvalue aggregation could collect the value 0 even when no zero-value measurements were recorded. (#8056)
+- Fix missing `request.GetBody` in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp` to correctly handle HTTP2 GOAWAY frame. (#8096)
 
 <!-- Released section -->
 <!-- Don't change this section unless doing release -->

exporters/otlp/otlplog/otlploghttp/client.go

@@ -263,6 +263,7 @@ func (c *httpClient) newRequest(ctx context.Context, body []byte) (request, erro
 	case NoCompression:
 		r.ContentLength = int64(len(body))
 		req.bodyReader = bodyReader(body)
+		req.GetBody = bodyReaderErr(body)
 	case GzipCompression:
 		// Ensure the content length is not used.
 		r.ContentLength = -1
@@ -283,6 +284,7 @@ func (c *httpClient) newRequest(ctx context.Context, body []byte) (request, erro
 		}
 
 		req.bodyReader = bodyReader(b.Bytes())
+		req.GetBody = bodyReaderErr(body)
 	}
 
 	return req, nil
@@ -295,6 +297,13 @@ func bodyReader(buf []byte) func() io.ReadCloser {
 	}
 }
 
+// bodyReaderErr returns a closure returning a new reader for buf.
+func bodyReaderErr(buf []byte) func() (io.ReadCloser, error) {
+	return func() (io.ReadCloser, error) {
+		return io.NopCloser(bytes.NewReader(buf)), nil
+	}
+}
+
 // request wraps an http.Request with a resettable body reader.
 type request struct {
 	*http.Request

exporters/otlp/otlplog/otlploghttp/client_test.go

@@ -20,6 +20,7 @@ import (
 	"math/big"
 	"net"
 	"net/http"
+	"net/http/httptest"
 	"net/url"
 	"strings"
 	"sync"
@@ -833,6 +834,58 @@ func TestConfig(t *testing.T) {
 	})
 }
 
+func TestGetBodyCalledOnRedirect(t *testing.T) {
+	// Test that req.GetBody is set correctly, allowing the HTTP transport
+	// to re-send the body on 307 redirects.
+	var mu sync.Mutex
+	var requestBodies [][]byte
+
+	handler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		body, err := io.ReadAll(r.Body)
+		if err != nil {
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		mu.Lock()
+		requestBodies = append(requestBodies, body)
+		isFirstRequest := len(requestBodies) == 1
+		mu.Unlock()
+
+		if isFirstRequest {
+			w.Header().Set("Location", "/v1/logs/final")
+			w.WriteHeader(http.StatusTemporaryRedirect)
+			return
+		}
+
+		w.Header().Set("Content-Type", "application/x-protobuf")
+		w.WriteHeader(http.StatusOK)
+	})
+
+	server := httptest.NewServer(handler)
+	defer server.Close()
+
+	opts := []Option{WithEndpoint(server.Listener.Addr().String()), WithInsecure()}
+	cfg := newConfig(opts)
+	client, err := newHTTPClient(t.Context(), cfg)
+	require.NoError(t, err)
+
+	exporter, err := newExporter(client, cfg)
+	require.NoError(t, err)
+	ctx := t.Context()
+	defer func() { _ = exporter.Shutdown(ctx) }()
+
+	err = exporter.Export(ctx, make([]log.Record, 1))
+	require.NoError(t, err)
+
+	mu.Lock()
+	defer mu.Unlock()
+
+	require.Len(t, requestBodies, 2, "expected 2 requests (original + redirect)")
+	assert.NotEmpty(t, requestBodies[0], "original request body should not be empty")
+	assert.Equal(t, requestBodies[0], requestBodies[1], "redirect body should match original")
+}
+
 // SetExporterID sets the exporter ID counter to v and returns the previous
 // value.
 //