From 727f03e2204a4203dda75df0c719e792b66bd5df Mon Sep 17 00:00:00 2001
From: Tyler Yahn <MrAlias@users.noreply.github.com>
Date: Wed, 10 Apr 2024 07:47:24 -0700
Subject: [PATCH] otlploghttp: Implement Exporter.Export (#5182)

---
 .../otlp/otlplog/otlploghttp/exporter.go      | 13 ++++-
 .../otlp/otlplog/otlploghttp/exporter_test.go | 56 +++++++++++++++++++
 .../otlploghttp/internal/transform/log.go     | 17 ++++++
 3 files changed, 84 insertions(+), 2 deletions(-)
 create mode 100644 exporters/otlp/otlplog/otlploghttp/internal/transform/log.go

diff --git a/exporters/otlp/otlplog/otlploghttp/exporter.go b/exporters/otlp/otlplog/otlploghttp/exporter.go
index 2338361e4c7..ac4c403a970 100644
--- a/exporters/otlp/otlplog/otlploghttp/exporter.go
+++ b/exporters/otlp/otlplog/otlploghttp/exporter.go
@@ -5,8 +5,10 @@ package otlploghttp // import "go.opentelemetry.io/otel/exporters/otlp/otlplog/o
 
 import (
 	"context"
+	"errors"
 	"sync/atomic"
 
+	"go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp/internal/transform"
 	"go.opentelemetry.io/otel/sdk/log"
 )
 
@@ -37,13 +39,20 @@ func newExporter(c *client, _ config) (*Exporter, error) {
 	return e, nil
 }
 
+// Used for testing.
+var transformResourceLogs = transform.ResourceLogs
+
 // Export transforms and transmits log records to an OTLP receiver.
 func (e *Exporter) Export(ctx context.Context, records []log.Record) error {
 	if e.stopped.Load() {
 		return nil
 	}
-	// TODO: implement.
-	return nil
+	otlp, err := transformResourceLogs(records)
+	if otlp != nil {
+		// Best effort upload of transformable logs.
+		err = errors.Join(err, e.client.Load().UploadLogs(ctx, otlp))
+	}
+	return err
 }
 
 // Shutdown shuts down the Exporter. Calls to Export or ForceFlush will perform
diff --git a/exporters/otlp/otlplog/otlploghttp/exporter_test.go b/exporters/otlp/otlplog/otlploghttp/exporter_test.go
index d818739a070..8779a1b2b9f 100644
--- a/exporters/otlp/otlplog/otlploghttp/exporter_test.go
+++ b/exporters/otlp/otlplog/otlploghttp/exporter_test.go
@@ -5,6 +5,7 @@ package otlploghttp
 
 import (
 	"context"
+	"errors"
 	"runtime"
 	"sync"
 	"sync/atomic"
@@ -14,8 +15,63 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/sdk/log"
+	logpb "go.opentelemetry.io/proto/otlp/logs/v1"
 )
 
+func TestExporterExportErrors(t *testing.T) {
+	var (
+		errUpload = errors.New("upload")
+		errTForm  = errors.New("transform")
+	)
+
+	c := &client{
+		uploadLogs: func(context.Context, *logpb.ResourceLogs) error {
+			return errUpload
+		},
+	}
+
+	orig := transformResourceLogs
+	transformResourceLogs = func(r []log.Record) (*logpb.ResourceLogs, error) {
+		return new(logpb.ResourceLogs), errTForm
+	}
+	t.Cleanup(func() { transformResourceLogs = orig })
+
+	e, err := newExporter(c, config{})
+	require.NoError(t, err, "New")
+
+	err = e.Export(context.Background(), make([]log.Record, 1))
+	assert.ErrorIs(t, err, errUpload)
+	assert.ErrorIs(t, err, errTForm)
+}
+
+func TestExporterExport(t *testing.T) {
+	var uploads int
+	c := &client{
+		uploadLogs: func(context.Context, *logpb.ResourceLogs) error {
+			uploads++
+			return nil
+		},
+	}
+
+	orig := transformResourceLogs
+	var got []log.Record
+	transformResourceLogs = func(r []log.Record) (*logpb.ResourceLogs, error) {
+		got = r
+		return new(logpb.ResourceLogs), nil
+	}
+	t.Cleanup(func() { transformResourceLogs = orig })
+
+	e, err := newExporter(c, config{})
+	require.NoError(t, err, "New")
+
+	ctx := context.Background()
+	want := make([]log.Record, 1)
+	assert.NoError(t, e.Export(ctx, want))
+
+	assert.Equal(t, 1, uploads, "client UploadLogs calls")
+	assert.Equal(t, want, got, "transformed log records")
+}
+
 func TestExporterShutdown(t *testing.T) {
 	ctx := context.Background()
 	e, err := New(ctx)
diff --git a/exporters/otlp/otlplog/otlploghttp/internal/transform/log.go b/exporters/otlp/otlplog/otlploghttp/internal/transform/log.go
new file mode 100644
index 00000000000..bea72f2991a
--- /dev/null
+++ b/exporters/otlp/otlplog/otlploghttp/internal/transform/log.go
@@ -0,0 +1,17 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package transform provides transformation functionality from the
+// sdk/log data-types into OTLP data-types.
+package transform // import "go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp/internal/transform"
+
+import (
+	lpb "go.opentelemetry.io/proto/otlp/logs/v1"
+
+	"go.opentelemetry.io/otel/sdk/log"
+)
+
+func ResourceLogs([]log.Record) (*lpb.ResourceLogs, error) {
+	// TODO: implement
+	return nil, nil
+}