Add aggregation usage to nodes usage (#4737) (#4758)

Relates: #4718, elastic/elasticsearch#55732

Co-authored-by: Russ Cam <[email protected]>

Author: github-actions[bot]

src/Nest/Cluster/NodesUsage/NodeUsageInformation.cs

@@ -11,6 +11,14 @@ namespace Nest
 {
 	public class NodeUsageInformation
 	{
+		/// <summary>
+		/// Aggregation usage.
+		/// <para />
+		/// Available in Elasticsearch 7.8.0+
+		/// </summary>
+		[DataMember(Name ="aggregations")]
+		public IReadOnlyDictionary<string, IReadOnlyDictionary<string, long>> Aggregations { get; internal set; }
+
 		[DataMember(Name ="rest_actions")]
 		public IReadOnlyDictionary<string, int> RestActions { get; internal set; }
 

tests/Tests/Cluster/NodesUsage/NodesUsageApiTests.cs

@@ -7,8 +7,10 @@
 using Elasticsearch.Net;
 using FluentAssertions;
 using Nest;
+using Tests.Core.Client;
 using Tests.Core.Extensions;
 using Tests.Core.ManagedElasticsearch.Clusters;
+using Tests.Domain;
 using Tests.Framework.EndpointTests;
 using Tests.Framework.EndpointTests.TestState;
 
@@ -24,6 +26,21 @@ public NodesUsageApiTests(ReadOnlyCluster cluster, EndpointUsage usage) : base(c
 		protected override HttpMethod HttpMethod => HttpMethod.GET;
 		protected override string UrlPath => "/_nodes/usage";
 
+		protected override void IntegrationSetup(IElasticClient client, CallUniqueValues values)
+		{
+			var searchResponse = client.Search<Project>(s => s
+				.Size(0)
+				.Aggregations(a => a
+					.Average("avg_commits", avg => avg
+						.Field(f => f.NumberOfCommits)
+					)
+				)
+			);
+
+			if (!searchResponse.IsValid)
+				throw new Exception($"Exception when setting up {nameof(NodesUsageApiTests)}: {searchResponse.DebugInformation}");
+		}
+
 		protected override LazyResponses ClientUsage() => Calls(
 			(client, f) => client.Nodes.Usage(),
 			(client, f) => client.Nodes.UsageAsync(),
@@ -43,9 +60,15 @@ protected override void ExpectResponse(NodesUsageResponse response)
 			response.Nodes.Should().NotBeNull();
 			response.Nodes.Should().HaveCount(1);
 
-			response.Nodes.First().Value.Timestamp.Should().BeBefore(DateTimeOffset.UtcNow);
-			response.Nodes.First().Value.Since.Should().BeBefore(DateTimeOffset.UtcNow);
-			response.Nodes.First().Value.RestActions.Should().NotBeNull();
+			var firstNode = response.Nodes.First();
+			firstNode.Value.Timestamp.Should().BeBefore(DateTimeOffset.UtcNow);
+			firstNode.Value.Since.Should().BeBefore(DateTimeOffset.UtcNow);
+			firstNode.Value.RestActions.Should().NotBeNull();
+
+			if (TestClient.Configuration.InRange(">=7.8.0"))
+			{
+				firstNode.Value.Aggregations.Should().NotBeNull().And.ContainKey("avg");
+			}
 		}
 	}
 }