Add deployment ID to debug data in HTML comment

src/live.asp.net/Services/DeploymentEnvironment.cs

@@ -0,0 +1,84 @@
+// Copyright (c) .NET Foundation. All rights reserved. 
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace live.asp.net.Services
+{
+    public class DeploymentEnvironment : IDeploymentEnvironment
+    {
+        private readonly string _contentRoot;
+        private readonly ILogger<DeploymentEnvironment> _logger;
+        private string _commitSha;
+
+        public DeploymentEnvironment(IHostingEnvironment hostingEnv, ILogger<DeploymentEnvironment> logger)
+        {
+            _contentRoot = hostingEnv.ContentRootPath;
+            _logger = logger;
+        }
+
+        public string DeploymentId
+        {
+            get
+            {
+                if (_commitSha == null)
+                {
+                    LoadCommitSha();
+                }
+
+                return _commitSha;
+            }
+        }
+
+        private void LoadCommitSha()
+        {
+            var kuduActiveDeploymentPath = Path.GetFullPath(Path.Combine(_contentRoot, "..", "deployments", "active"));
+            try
+            {
+                if (File.Exists(kuduActiveDeploymentPath))
+                {
+                    _logger.LogDebug("Kudu active deployment file found, using it to set DeploymentID");
+                    _commitSha = File.ReadAllText(kuduActiveDeploymentPath) + "(kudu)";
+                }
+                else
+                {
+                    _logger.LogDebug("Kudu active deployment file not found, using git to set DeploymentID");
+                    var git = Process.Start(new ProcessStartInfo
+                    {
+                        FileName = "git",
+                        Arguments = "rev-parse HEAD",
+                        UseShellExecute = false,
+                        RedirectStandardOutput = true,
+                        CreateNoWindow = true
+                    });
+                    var gitOut = "";
+                    while (!git.StandardOutput.EndOfStream)
+                    {
+                        gitOut += git.StandardOutput.ReadLine();
+                    }
+                    gitOut += " (local)";
+
+                    git.WaitForExit();
+                    if (git.ExitCode != 0)
+                    {
+                        _logger.LogDebug("Problem using git to set deployment ID:\r\n  git exit code: {0}\r\n git output: {1}", git.ExitCode, _commitSha);
+                        _commitSha = "(Could not determine deployment ID)";
+                    }
+                    else
+                    {
+                        _commitSha = gitOut;
+                    }
+                }
+            }
+            catch (Exception ex)
+            {
+                _logger.LogError(0, ex, "Error determining deployment ID");
+                _commitSha = "(Error determining deployment ID)";
+            }
+        }
+    }
+}

src/live.asp.net/Services/IDeploymentEnvironment.cs

@@ -0,0 +1,10 @@
+// Copyright (c) .NET Foundation. All rights reserved. 
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+namespace live.asp.net.Services
+{
+    public interface IDeploymentEnvironment
+    {
+        string DeploymentId { get; }
+    }
+}

src/live.asp.net/Startup.cs

@@ -67,6 +67,8 @@ public void ConfigureServices(IServiceCollection services)
 
             services.AddScoped<IShowsService, YouTubeShowsService>();
 
+            services.AddSingleton<IDeploymentEnvironment, DeploymentEnvironment>();
+
             if (string.IsNullOrEmpty(Configuration["AppSettings:AzureStorageConnectionString"]))
             {
                 services.AddSingleton<ILiveShowDetailsService, FileSystemLiveShowDetailsService>();

src/live.asp.net/Views/Shared/_Layout.cshtml

@@ -1,4 +1,5 @@
 @inject Microsoft.AspNetCore.Hosting.IHostingEnvironment HostingEnvironment
+@inject live.asp.net.Services.IDeploymentEnvironment DeploymentEnvironment
 
 <!DOCTYPE html>
 <html>
@@ -63,6 +64,7 @@
 <cache>
 <!-- Environment: @HostingEnvironment.EnvironmentName -->
 <!-- Application: @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Application.ApplicationName, @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Application.ApplicationVersion -->
+<!-- Deployment: @DeploymentEnvironment.DeploymentId -->
 <!-- Framework: @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Application.RuntimeFramework -->
 <!-- Runtime: @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Runtime.RuntimeType, @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Runtime.RuntimeArchitecture, @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Runtime.RuntimeVersion -->
 <!-- OS: @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Runtime.OperatingSystem @Microsoft.Extensions.PlatformAbstractions.PlatformServices.Default.Runtime.OperatingSystemVersion  -->

src/live.asp.net/appsettings.json

@@ -18,7 +18,7 @@
   "Logging": {
     "IncludeScopes": false,
     "LogLevel": {
-      "Default": "Verbose",
+      "Default": "Debug",
       "System": "Information",
       "Microsoft": "Information"
     }