Move public changelog registry ownership to the scrubber Lambda

src/infra/docs-lambda-changelog-scrubber/EmfMetricsEmitter.cs

@@ -0,0 +1,112 @@
+// 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.Text.Json;
+using System.Text.Json.Serialization;
+using Elastic.Changelog.Reconciliation;
+
+namespace Elastic.Documentation.Lambda.ChangelogScrubber;
+
+/// <summary>
+/// Emits the per-invocation reconcile counters as a CloudWatch Embedded Metric Format line
+/// (elastic/docs-eng-team#688 Phase 0 observability: these numbers gate any later SQS/Lambda
+/// tuning). The counter names are static, so the payload is a fixed source-generated contract;
+/// it is written to stdout unwrapped, which is what the EMF parser requires.
+/// </summary>
+internal static class EmfMetricsEmitter
+{
+	private const string Namespace = "docs-changelog-scrubber";
+
+	private static readonly IReadOnlyList<EmfMetricDefinition> MetricDefinitions =
+	[
+		new() { Name = "ObjectReconciles" },
+		new() { Name = "ObjectReconcileRetries" },
+		new() { Name = "GroupReconciles" },
+		new() { Name = "RegistryWrites" },
+		new() { Name = "RegistryDeletes" },
+		new() { Name = "RegistryUnchanged" },
+		new() { Name = "WriteConflicts" },
+		new() { Name = "ObjectsListed" },
+		new() { Name = "EntriesRecomputed" },
+		new() { Name = "ShallowRegistryWrites" },
+		new() { Name = "ShallowRegistryUnchanged" },
+		new() { Name = "FailedMessages" }
+	];
+
+	public static void Emit(ReconcileMetrics metrics)
+	{
+		var payload = new EmfPayload
+		{
+			Aws = new EmfEnvelope
+			{
+				Timestamp = DateTimeOffset.UtcNow.ToUnixTimeMilliseconds(),
+				CloudWatchMetrics =
+				[
+					new EmfMetricDirective
+					{
+						Namespace = Namespace,
+						Dimensions = [[]],
+						Metrics = MetricDefinitions
+					}
+				]
+			},
+			ObjectReconciles = metrics.ObjectReconciles,
+			ObjectReconcileRetries = metrics.ObjectReconcileRetries,
+			GroupReconciles = metrics.GroupReconciles,
+			RegistryWrites = metrics.RegistryWrites,
+			RegistryDeletes = metrics.RegistryDeletes,
+			RegistryUnchanged = metrics.RegistryUnchanged,
+			WriteConflicts = metrics.WriteConflicts,
+			ObjectsListed = metrics.ObjectsListed,
+			EntriesRecomputed = metrics.EntriesRecomputed,
+			ShallowRegistryWrites = metrics.ShallowRegistryWrites,
+			ShallowRegistryUnchanged = metrics.ShallowRegistryUnchanged,
+			FailedMessages = metrics.FailedMessages
+		};
+
+		Console.WriteLine(JsonSerializer.Serialize(payload, EmfJsonContext.Default.EmfPayload));
+	}
+}
+
+/// <summary>One EMF log line: the <c>_aws</c> envelope plus the metric values as top-level members.</summary>
+internal sealed record EmfPayload
+{
+	[JsonPropertyName("_aws")]
+	public required EmfEnvelope Aws { get; init; }
+
+	public required int ObjectReconciles { get; init; }
+	public required int ObjectReconcileRetries { get; init; }
+	public required int GroupReconciles { get; init; }
+	public required int RegistryWrites { get; init; }
+	public required int RegistryDeletes { get; init; }
+	public required int RegistryUnchanged { get; init; }
+	public required int WriteConflicts { get; init; }
+	public required int ObjectsListed { get; init; }
+	public required int EntriesRecomputed { get; init; }
+	public required int ShallowRegistryWrites { get; init; }
+	public required int ShallowRegistryUnchanged { get; init; }
+	public required int FailedMessages { get; init; }
+}
+
+internal sealed record EmfEnvelope
+{
+	public required long Timestamp { get; init; }
+	public required IReadOnlyList<EmfMetricDirective> CloudWatchMetrics { get; init; }
+}
+
+internal sealed record EmfMetricDirective
+{
+	public required string Namespace { get; init; }
+	public required IReadOnlyList<IReadOnlyList<string>> Dimensions { get; init; }
+	public required IReadOnlyList<EmfMetricDefinition> Metrics { get; init; }
+}
+
+internal sealed record EmfMetricDefinition
+{
+	public required string Name { get; init; }
+	public string Unit { get; init; } = "Count";
+}
+
+[JsonSerializable(typeof(EmfPayload))]
+internal sealed partial class EmfJsonContext : JsonSerializerContext;

src/infra/docs-lambda-changelog-scrubber/LambdaLoggerFactory.cs

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+// 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 Amazon.Lambda.Core;
+using Microsoft.Extensions.Logging;
+using LogLevel = Microsoft.Extensions.Logging.LogLevel;
+
+namespace Elastic.Documentation.Lambda.ChangelogScrubber;
+
+/// <summary>
+/// Routes <see cref="ILogger"/> calls from the shared Elastic.Changelog processing code to the
+/// Lambda's own logger, so the extracted processor stays free of Lambda dependencies.
+/// </summary>
+internal sealed class LambdaLoggerFactory(ILambdaLogger lambdaLogger) : ILoggerFactory
+{
+	public ILogger CreateLogger(string categoryName) => new LambdaLoggerAdapter(categoryName, lambdaLogger);
+
+	public void AddProvider(ILoggerProvider provider)
+	{
+		// Providers are meaningless here; everything goes to the Lambda logger.
+	}
+
+	public void Dispose()
+	{
+	}
+
+	private sealed class LambdaLoggerAdapter(string categoryName, ILambdaLogger lambdaLogger) : ILogger
+	{
+		public IDisposable? BeginScope<TState>(TState state) where TState : notnull => null;
+
+		public bool IsEnabled(LogLevel logLevel) => logLevel >= LogLevel.Information;
+
+		public void Log<TState>(LogLevel logLevel, EventId eventId, TState state, Exception? exception, Func<TState, Exception?, string> formatter)
+		{
+			if (!IsEnabled(logLevel))
+				return;
+
+			var message = $"{categoryName}: {formatter(state, exception)}";
+			if (exception is not null)
+				message = $"{message} | {exception}";
+
+			lambdaLogger.Log(MapLevel(logLevel), message);
+		}
+
+		private static string MapLevel(LogLevel level) => level switch
+		{
+			LogLevel.Trace => "TRACE",
+			LogLevel.Debug => "DEBUG",
+			LogLevel.Information => "INFO",
+			LogLevel.Warning => "WARN",
+			LogLevel.Error => "ERROR",
+			LogLevel.Critical => "CRITICAL",
+			_ => "INFO"
+		};
+	}
+}