Ensure we support endpoints with subpaths to write to as well (Elasticsearch as a service)

src/Elastic.Ingest.Elasticsearch/DataStreams/DataStreamChannel.cs

@@ -24,8 +24,8 @@ public DataStreamChannel(DataStreamChannelOptions<TEvent> options, ICollection<I
 	{
 		var dataStream = Options.DataStream.ToString();
 
-		_url = $"/{dataStream}{base.BulkUrl}";
-		
+		_url = $"{dataStream}/{base.BulkUrl}";
+
 		_fixedHeader = new CreateOperation();
 	}
 

src/Elastic.Ingest.Elasticsearch/ElasticsearchChannelBase.cs

@@ -47,7 +47,7 @@ protected override bool Retry(BulkResponse response)
 	/// <summary>
 	/// The URL for the bulk request.
 	/// </summary>
-	protected virtual string BulkUrl => "/_bulk";
+	protected virtual string BulkUrl => "_bulk";
 
 	/// <inheritdoc cref="ResponseItemsBufferedChannelBase{TChannelOptions,TEvent,TResponse,TBulkResponseItem}.RetryAllItems"/>
 	protected override bool RetryAllItems(BulkResponse response) => response.ApiCallDetails.HttpStatusCode == 429;

src/Elastic.Ingest.Elasticsearch/Indices/IndexChannel.cs

@@ -30,7 +30,7 @@ public IndexChannel(IndexChannelOptions<TEvent> options, ICollection<IChannelCal
 		// We can later avoid the overhead of calculating and adding the index name to the operation headers.
 		if (string.Format(Options.IndexFormat, DateTimeOffset.Now).Equals(Options.IndexFormat, StringComparison.Ordinal))
 		{
-			_url = $"/{Options.IndexFormat}{base.BulkUrl}";
+			_url = $"{Options.IndexFormat}/{base.BulkUrl}";
 			_skipIndexNameOnOperations = true;
 		}
 

tests/Elastic.Ingest.Elasticsearch.Tests/ChannelTestWithSingleDocResponseBase.cs

@@ -10,9 +10,12 @@ namespace Elastic.Ingest.Elasticsearch.Tests;
 
 public abstract class ChannelTestWithSingleDocResponseBase
 {
-	protected static readonly ITransport _transport = new DistributedTransport<TransportConfiguration>(
-		new TransportConfiguration(new SingleNodePool(new Uri("http://localhost:9200")),
-			new InMemoryRequestInvoker(Encoding.UTF8.GetBytes("{\"items\":[{\"create\":{\"status\":201}}]}")))
+	protected ChannelTestWithSingleDocResponseBase(string url = "https://localhost:9200") =>
+		Transport = new DistributedTransport<TransportConfiguration>(
+			new TransportConfiguration(new SingleNodePool(new Uri(url)),
+					new InMemoryRequestInvoker(Encoding.UTF8.GetBytes("{\"items\":[{\"create\":{\"status\":201}}]}")))
 				.DisablePing()
 				.EnableDebugMode());
+
+	protected ITransport Transport { get; }
 }

tests/Elastic.Ingest.Elasticsearch.Tests/DataStreamChannelTests.cs

@@ -20,7 +20,7 @@ public void DataStreamChannel_UsesCorrectUrlAndOperationHeader()
 
 		var wait = new ManualResetEvent(false);
 
-		using var channel = new DataStreamChannel<TestDocument>(new DataStreamChannelOptions<TestDocument>(_transport)
+		using var channel = new DataStreamChannel<TestDocument>(new DataStreamChannelOptions<TestDocument>(Transport)
 		{
 			BufferOptions = new()
 			{

tests/Elastic.Ingest.Elasticsearch.Tests/IndexChannelTests.cs

@@ -22,13 +22,13 @@ public void IndexChannel_WithFixedIndexName_UsesCorrectUrlAndOperationHeader() =
 	public void IndexChannel_WithDynamicIndexName_UsesCorrectUrlAndOperationHeader() =>
 		ExecuteAndAssert("/_bulk", "{\"create\":{\"_index\":\"dotnet-2023.07.29\"}}");
 
-	private static void ExecuteAndAssert(string expectedUrl, string expectedOperationHeader, string indexName = null)
+	private void ExecuteAndAssert(string expectedUrl, string expectedOperationHeader, string indexName = null)
 	{
 		ApiCallDetails callDetails = null;
 
 		var wait = new ManualResetEvent(false);
 
-		var options = new IndexChannelOptions<TestDocument>(_transport)
+		var options = new IndexChannelOptions<TestDocument>(Transport)
 		{
 			BufferOptions = new()
 			{

tests/Elastic.Ingest.Elasticsearch.Tests/SubPathTests.cs

@@ -0,0 +1,64 @@
+// Licensed to Elasticsearch B.V under one or more agreements.
+// Elasticsearch B.V licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information
+
+using System;
+using System.IO;
+using System.Threading;
+using Elastic.Ingest.Elasticsearch.Indices;
+using Elastic.Transport;
+using FluentAssertions;
+using Xunit;
+
+namespace Elastic.Ingest.Elasticsearch.Tests;
+
+public class SubPathTests : ChannelTestWithSingleDocResponseBase
+{
+	public SubPathTests() : base("https://localhost:9200/subpath") { }
+
+	[Fact]
+	public void IndexChannel_WithFixedIndexName_UsesCorrectUrlAndOperationHeader() =>
+		ExecuteAndAssert("/subpath/fixed-index/_bulk", "{\"create\":{}}", "fixed-index");
+
+	[Fact]
+	public void IndexChannel_WithDynamicIndexName_UsesCorrectUrlAndOperationHeader() =>
+		ExecuteAndAssert("/subpath/_bulk", "{\"create\":{\"_index\":\"dotnet-2023.07.29\"}}");
+
+	private void ExecuteAndAssert(string expectedUrl, string expectedOperationHeader, string indexName = null)
+	{
+		ApiCallDetails callDetails = null;
+		var wait = new ManualResetEvent(false);
+
+		var options = new IndexChannelOptions<TestDocument>(Transport)
+		{
+			BufferOptions = new()
+			{
+				OutboundBufferMaxSize = 1
+			},
+			ExportResponseCallback = (response, _) =>
+			{
+				callDetails = response.ApiCallDetails;
+				wait.Set();
+			},
+			TimestampLookup = _ => new DateTimeOffset(2023, 07, 29, 20, 00, 00, TimeSpan.Zero),
+		};
+
+		if (indexName is not null)
+		{
+			options.IndexFormat = indexName;
+		}
+
+		using var channel = new IndexChannel<TestDocument>(options);
+
+		channel.TryWrite(new TestDocument());
+		wait.WaitOne();
+
+		callDetails.Should().NotBeNull();
+		callDetails.Uri.AbsolutePath.Should().Be(expectedUrl);
+
+		var stream = new MemoryStream(callDetails.RequestBodyInBytes);
+		var sr = new StreamReader(stream);
+		var operation = sr.ReadLine();
+		operation.Should().Be(expectedOperationHeader);
+	}
+}