Merge pull request #2 from manan-habib/main

Http Client Metrics package Implementation

Prometheus.Client.HttpClient.sln

@@ -0,0 +1,31 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.7.34003.232
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Prometheus.Client.HttpClient", "src\Prometheus.Client.HttpClient\Prometheus.Client.HttpClient.csproj", "{C4504E36-2F22-4BAC-8772-2BF1AC960537}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Prometheus.Client.HttpClient.Tests", "tests\Prometheus.Client.HttpClient.Tests\Prometheus.Client.HttpClient.Tests.csproj", "{37ECBCA1-9464-49B8-8D6B-95D0FC050E92}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{C4504E36-2F22-4BAC-8772-2BF1AC960537}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{C4504E36-2F22-4BAC-8772-2BF1AC960537}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{C4504E36-2F22-4BAC-8772-2BF1AC960537}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{C4504E36-2F22-4BAC-8772-2BF1AC960537}.Release|Any CPU.Build.0 = Release|Any CPU
+		{37ECBCA1-9464-49B8-8D6B-95D0FC050E92}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{37ECBCA1-9464-49B8-8D6B-95D0FC050E92}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{37ECBCA1-9464-49B8-8D6B-95D0FC050E92}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{37ECBCA1-9464-49B8-8D6B-95D0FC050E92}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ExtensibilityGlobals) = postSolution
+		SolutionGuid = {336BF78E-D206-4FCB-A5AE-013A0AFDEB04}
+	EndGlobalSection
+EndGlobal

README.md

@@ -1,14 +1,14 @@
-# prom-tmpl
+# prom-client-httpclient
 
-[![sync](https://img.shields.io/github/actions/workflow/status/prom-client-net/prom-tmpl/sync.yml?branch=main&label=sync&logo=github&style=flat-square)](https://github.com/prom-client-net/prom-tmpl/actions/workflows/sync.yml)
-[![license](https://img.shields.io/github/license/prom-client-net/prom-tmpl?style=flat-square)](https://github.com/prom-client-net/prom-tmpl/blob/main/LICENSE)
+[![ci](https://img.shields.io/github/actions/workflow/status/prom-client-net/prom-client-httpclient/ci.yml?branch=main&label=ci&logo=github&style=flat-square)](https://github.com/prom-client-net/prom-client-httpclient/actions/workflows/ci.yml)
+[![license](https://img.shields.io/github/license/prom-client-net/prom-client-httpclient?style=flat-square)](https://github.com/prom-client-net/prom-client-httpclient/blob/main/LICENSE)
 
 ## Contribute
 
 Contributions to the package are always welcome!
 
-* Report any bugs or issues you find on the [issue tracker](https://github.com/prom-client-net/prom-tmpl/issues).
-* You can grab the source code at the package's [git repository](https://github.com/prom-client-net/prom-tmpl).
+* Report any bugs or issues you find on the [issue tracker](https://github.com/prom-client-net/prom-client-httpclient/issues).
+* You can grab the source code at the package's [git repository](https://github.com/prom-client-net/prom-client-httpclient).
 
 ## License
 

src/Prometheus.Client.HttpClient/Constants.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+
+namespace Prometheus.Client.HttpClient
+{
+    public static class Constants
+    {
+        public const string Method = "method";
+        public const string Host = "host";
+        public const string Client = "client";
+        public const string StatusCode = "status_code";
+
+        public const string CountMetricName = "httpclient_requests_sent_total";
+        public const string CountMetricHelp = "Count of HTTP requests that have been completed by an HttpClient.";
+        public const string InProgresMetricName = "httpclient_requests_in_progress";
+        public const string InProgresMetricHelp = "Number of requests currently being executed by an HttpClient.";
+        public const string RequestDurationMetricName = "httpclient_request_duration_seconds";
+        public const string RequestDurationMetricHelp = "Duration histogram of HTTP requests performed by an HttpClient.";
+        public const string ResponseDurationMetricName = "httpclient_response_duration_seconds";
+        public const string ResponseDurationMetricHelp = "Duration histogram of HTTP requests performed by an HttpClient, measuring the duration until the HTTP response finished being processed.";
+    }
+}

src/Prometheus.Client.HttpClient/HttpClientMetricsExtensions.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+using Microsoft.Extensions.DependencyInjection;
+using Prometheus.Client.Collectors;
+using Prometheus.Client.HttpClient.MessageHandlers;
+
+namespace Prometheus.Client.HttpClient
+{
+    public static class HttpClientMetricsExtensions
+    {
+        /// <summary>
+        /// Configures the HttpClient pipeline to collect Prometheus metrics.
+        /// </summary>
+        public static IHttpClientBuilder AddHttpClientMetrics(this IHttpClientBuilder builder, Action<HttpClientMetricsOptions> configure)
+        {
+            var options = new HttpClientMetricsOptions();
+
+            configure?.Invoke(options);
+
+            builder.AddHttpClientMetrics(options);
+
+            return builder;
+        }
+
+        /// <summary>
+        /// Configures the HttpClient pipeline to collect Prometheus metrics.
+        /// </summary>
+        public static IHttpClientBuilder AddHttpClientMetrics(this IHttpClientBuilder builder,  HttpClientMetricsOptions options = null)
+        {
+            options ??= new HttpClientMetricsOptions();
+
+            builder = builder.AddHttpMessageHandler(sp =>
+            {
+                options.CollectorRegistry ??= (ICollectorRegistry)sp.GetService(typeof(ICollectorRegistry)) ?? Metrics.DefaultCollectorRegistry;
+                return new HttpClientInProgressHandler(new MetricFactory(options.CollectorRegistry), builder.Name);
+            });
+            builder = builder.AddHttpMessageHandler(sp =>
+            {
+                options.CollectorRegistry ??= (ICollectorRegistry)sp.GetService(typeof(ICollectorRegistry)) ?? Metrics.DefaultCollectorRegistry;
+                return new HttpClientRequestDurationHandler(new MetricFactory(options.CollectorRegistry), builder.Name);
+            });
+
+            return builder;
+        }
+    }
+}

src/Prometheus.Client.HttpClient/HttpClientMetricsOptions.cs

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+using System;
+using System.Collections.Generic;
+using System.Text;
+using Prometheus.Client.Collectors;
+
+namespace Prometheus.Client.HttpClient
+{
+    public class HttpClientMetricsOptions
+    {
+        /// <summary>
+        /// Allows you to override the registry for default metric.
+        /// Value will be ignored if a custom metric is set.
+        /// </summary>
+        public ICollectorRegistry CollectorRegistry { get; set; }
+    }
+}

src/Prometheus.Client.HttpClient/MessageHandlers/HttpClientInProgressHandler.cs

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+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Prometheus.Client.HttpClient.MessageHandlers
+{
+    public class HttpClientInProgressHandler : HttpClientMessageHandlerBase<IMetricFamily<IGauge, ValueTuple<string, string, string, string>>, IGauge>
+    {
+        public HttpClientInProgressHandler(IMetricFactory metricFactory, string clientName)
+            : base(metricFactory, clientName)
+        {
+        }
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            HttpResponseMessage response = null;
+            var metric = WithLabels(request, null);
+
+            metric.Inc();
+
+            try
+            {
+                response = await base.SendAsync(request, cancellationToken);
+            }
+            finally 
+            {
+                metric.Dec();
+            }
+
+            return response;
+        }
+
+        protected override IMetricFamily<IGauge, ValueTuple<string, string, string, string>> CreateMetricInstance() => MetricFactory.CreateGauge(Constants.InProgresMetricName, Constants.InProgresMetricHelp, (Constants.Host, Constants.Client, Constants.Method, Constants.StatusCode));
+    }
+}

src/Prometheus.Client.HttpClient/MessageHandlers/HttpClientMessageHandlerBase.cs

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+using System;
+using System.Net.Http;
+
+namespace Prometheus.Client.HttpClient.MessageHandlers
+{
+    public abstract class HttpClientMessageHandlerBase<TMetricFamily, TMetric> : DelegatingHandler
+        where TMetricFamily: IMetricFamily<TMetric, ValueTuple<string, string, string, string>>
+        where TMetric : IMetric
+    {
+        private readonly string _clientName;
+        private readonly TMetricFamily _metric;
+        protected readonly IMetricFactory MetricFactory;
+        protected abstract TMetricFamily CreateMetricInstance();
+        protected HttpClientMessageHandlerBase(IMetricFactory metricFactory, string clientName)
+        {
+            _clientName = clientName;
+            MetricFactory = metricFactory;
+            _metric = CreateMetricInstance();
+        }
+
+        protected TMetric WithLabels(HttpRequestMessage httpRequest, HttpResponseMessage httpResponse)
+        {
+            var host = httpRequest?.RequestUri?.Host ?? string.Empty;
+            var method = httpRequest?.Method?.Method ?? string.Empty;
+            var statusCode = GetStatusCode(httpResponse);
+
+            return _metric.WithLabels((host, _clientName, method, statusCode));
+        }
+
+        private string GetStatusCode(HttpResponseMessage httpResponse)
+        {
+            if (httpResponse == null)
+                return string.Empty;
+
+            return Convert.ToString((int)httpResponse.StatusCode);
+        }
+    }
+}

src/Prometheus.Client.HttpClient/MessageHandlers/HttpClientRequestDurationHandler.cs

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+using System;
+using System.Diagnostics;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Prometheus.Client.HttpClient.MessageHandlers
+{
+    public class HttpClientRequestDurationHandler : HttpClientMessageHandlerBase<IMetricFamily<IHistogram, ValueTuple<string,string,string,string>>, IHistogram>
+    {
+        public HttpClientRequestDurationHandler(IMetricFactory metricFactory, string clientName)
+            : base(metricFactory, clientName)
+        {
+        }
+
+        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            var stopWatch = Stopwatch.StartNew();
+
+            HttpResponseMessage response = null;
+
+            try
+            {
+                response = await base.SendAsync(request, cancellationToken);
+                return response;
+            }
+            finally
+            {
+                stopWatch.Stop();
+
+                WithLabels(request, response).Observe(stopWatch.Elapsed.TotalSeconds);
+            }
+        }
+
+        protected override IMetricFamily<IHistogram, ValueTuple<string, string, string, string>> CreateMetricInstance() => MetricFactory.CreateHistogram(Constants.RequestDurationMetricName, Constants.RequestDurationMetricHelp, (Constants.Host, Constants.Client, Constants.Method, Constants.StatusCode));
+    }
+}

src/Prometheus.Client.HttpClient/Prometheus.Client.HttpClient.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFrameworks>netstandard2.1;net6.0;net7.0</TargetFrameworks>
+    <SignAssembly>False</SignAssembly>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="Prometheus.Client" Version="5.2.0" />
+  </ItemGroup>
+
+  <ItemGroup Condition="'$(TargetFramework)' == 'netstandard2.1'">
+    <PackageReference Include="Microsoft.Extensions.Http" Version="3.1.32" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net6.0'">
+    <PackageReference Include="Microsoft.Extensions.Http" Version="6.0.0" />
+  </ItemGroup>
+  <ItemGroup Condition="'$(TargetFramework)' == 'net7.0'">
+    <PackageReference Include="Microsoft.Extensions.Http" Version="7.0.0" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="$(MSBuildProjectName).Tests, PublicKey=002400000480000094000000060200000024000052534131000400000100010005cd7fff58a5f07dd84ba50975028ab8f3e6d86aa42579628f27012bdcb335ab71f06ec08a39d4308e0be6d63507b9afdd4763e7625251a68912bfadb5b411627a397e6f70a20eb28f5c841e8e8354fc19a1d538ee079575a59678edc98597f98f659b697c46d5f1ca1f1b0b8be057c9eb0a1496a2da78074760026ee98a3ceb" />
+  </ItemGroup>
+
+</Project>

tests/Prometheus.Client.HttpClient.Tests/GlobalUsings.cs

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+global using Xunit;