Add ability for ContainerResource to reach ProjectResource by name in Run mode

.gitignore

@@ -431,3 +431,5 @@ FodyWeavers.xsd
 **/*/azure.yaml
 **/*/next-steps.md
 
+# Nginx config files generated by WithContainerProxy
+/samples/Metrics/MetricsApp.AppHost/*-proxy.nginx.conf

samples/Metrics/MetricsApp.AppHost/ContainerProxy/ContainerProxyAnnotation.cs

@@ -0,0 +1,13 @@
+namespace MetricsApp.AppHost.ContainerProxy;
+
+internal sealed class ContainerProxyAnnotation : IResourceAnnotation
+{
+    public ContainerProxyAnnotation(IResourceWithEndpoints proxiedResource)
+    {
+        ProxiedResource = proxiedResource;
+    }
+
+    public string? FilePath { get; set; }
+
+    public IResourceWithEndpoints ProxiedResource { get; }
+}

samples/Metrics/MetricsApp.AppHost/ContainerProxy/ContainerProxyResourceExtensions.cs

@@ -0,0 +1,31 @@
+using Aspire.Hosting.Lifecycle;
+
+namespace MetricsApp.AppHost.ContainerProxy;
+
+public static class ContainerProxyResourceExtensions
+{
+    /// <summary>
+    /// Adds nginx container with name of <see cref="projectResourceBuilder"/> resource, which will proxy requests from other <see cref="ContainerResource"/>s to <see cref="ProjectResource"/> identified by <see cref="projectResourceBuilder"/>.
+    /// </summary>
+    /// <param name="projectResourceBuilder"></param>
+    /// <returns>The <see cref="IResourceBuilder{T}"/>.</returns>
+    public static IResourceBuilder<ProjectResource> WithContainerProxy(this IResourceBuilder<ProjectResource> projectResourceBuilder)
+    {
+        projectResourceBuilder.ApplicationBuilder.Services.TryAddLifecycleHook<ContainerProxyResourceLifecycleHook>();
+
+        projectResourceBuilder.ApplicationBuilder.AddContainer(projectResourceBuilder.Resource.Name + "-proxy", "nginx")
+            .WithAnnotation(new ContainerProxyAnnotation(projectResourceBuilder.Resource))
+            .WithContainerRuntimeArgs(context =>
+            {
+                context.Args.Add("--network-alias");
+                context.Args.Add(projectResourceBuilder.Resource.Name);
+
+                context.Args.Add("--hostname");
+                context.Args.Add(projectResourceBuilder.Resource.Name);
+            })
+            .WithHttpEndpoint(targetPort: 80, name: "http")
+            .ExcludeFromManifest();
+
+        return projectResourceBuilder;
+    }
+}

samples/Metrics/MetricsApp.AppHost/ContainerProxy/ContainerProxyResourceLifecycleHook.cs

@@ -0,0 +1,104 @@
+using Aspire.Hosting.Lifecycle;
+using CliWrap;
+using CliWrap.EventStream;
+using Microsoft.Extensions.Hosting;
+using Microsoft.Extensions.Logging;
+
+namespace MetricsApp.AppHost.ContainerProxy
+{
+    internal sealed class ContainerProxyResourceLifecycleHook : IDistributedApplicationLifecycleHook, IAsyncDisposable
+    {
+        private const string NginxConfigTemplate = @"
+events {}
+
+http {
+    server {
+        listen 80;
+
+        location / {
+            proxy_pass http://{host}:{port};
+        }
+    }
+}
+";
+
+        private readonly ILogger<ContainerProxyResourceLifecycleHook> _logger;
+        private readonly IHostEnvironment _hostEnvironment;
+        private readonly string _networkNamePrefix;
+        private readonly string _networkName;
+
+        public ContainerProxyResourceLifecycleHook(
+            ILogger<ContainerProxyResourceLifecycleHook> logger,
+            IHostEnvironment hostEnvironment)
+        {
+            _logger = logger;
+            _hostEnvironment = hostEnvironment;
+
+            _networkNamePrefix = $"{hostEnvironment.ApplicationName}_Proxy_";
+            _networkName = hostEnvironment.ApplicationName + Guid.NewGuid().ToString().Substring(0, 6);
+        }
+
+        public async Task BeforeStartAsync(DistributedApplicationModel appModel, CancellationToken cancellationToken = default)
+        {
+            await CleanupNetworks(CancellationToken.None).ConfigureAwait(false);
+
+            _logger.LogInformation("Creating docker network {Network}.", _networkName);
+            await Cli.Wrap("docker").WithArguments($"network create {_networkName}").ExecuteAsync(cancellationToken).ConfigureAwait(false);
+
+            foreach (var containerResource in appModel.Resources.OfType<ContainerResource>())
+            {
+                var proxyAnnotation = containerResource.Annotations.OfType<ContainerProxyAnnotation>().SingleOrDefault();
+                if (proxyAnnotation != null)
+                {
+                    var confFilePath = Path.Combine(_hostEnvironment.ContentRootPath, $"{containerResource.Name}.nginx.conf");
+                    proxyAnnotation.FilePath = confFilePath;
+                    containerResource.Annotations.Add(new ContainerMountAnnotation(confFilePath, "/etc/nginx/nginx.conf", ContainerMountType.BindMount, true));
+                }
+
+                containerResource.Annotations.Add(new ContainerRuntimeArgsCallbackAnnotation(context =>
+                {
+                    context.Add("--network");
+                    context.Add(_networkName);
+                }));
+            }
+        }
+
+        public Task AfterEndpointsAllocatedAsync(DistributedApplicationModel appModel, CancellationToken cancellationToken = default)
+        {
+            foreach (var containerResource in appModel.Resources.OfType<ContainerResource>())
+            {
+                var proxyAnnotation = containerResource.Annotations.OfType<ContainerProxyAnnotation>().SingleOrDefault();
+                if (proxyAnnotation != null && proxyAnnotation.FilePath != null)
+                {
+                    var endpoint = proxyAnnotation.ProxiedResource.GetEndpoint("http");
+                    var configString = NginxConfigTemplate
+                        .Replace("{host}", "host.docker.internal")
+                        .Replace("{port}", endpoint.Port.ToString());
+                    File.WriteAllText(proxyAnnotation.FilePath, configString);
+                }
+            }
+
+            return Task.CompletedTask;
+        }
+
+        public async ValueTask DisposeAsync()
+        {
+            await CleanupNetworks(CancellationToken.None).ConfigureAwait(false);
+        }
+
+        private async Task CleanupNetworks(CancellationToken cancellationToken)
+        {
+            var oldNetworks = Cli.Wrap("docker")
+                .WithArguments("network ls --format '{{.Name}}'")
+                .ListenAsync(cancellationToken)
+                .ToBlockingEnumerable(cancellationToken)
+                .OfType<StandardOutputCommandEvent>()
+                .Where(e => e.Text.StartsWith(_networkNamePrefix));
+            foreach (var oldNetwork in oldNetworks)
+            {
+                _logger.LogInformation("Deleting docker network {Network}.", oldNetwork);
+                await Cli.Wrap("docker").WithArguments($"network rm {oldNetwork}").ExecuteAsync(cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+}

samples/Metrics/MetricsApp.AppHost/MetricsApp.AppHost.csproj

@@ -10,6 +10,7 @@
 
   <ItemGroup>
     <PackageReference Include="Aspire.Hosting.AppHost" Version="8.0.1" />
+    <PackageReference Include="CliWrap" Version="3.6.6" />
 
     <ProjectReference Include="..\MetricsApp\MetricsApp.csproj" />
   </ItemGroup>

samples/Metrics/MetricsApp.AppHost/Program.cs

@@ -1,12 +1,15 @@
-var builder = DistributedApplication.CreateBuilder(args);
+using MetricsApp.AppHost.ContainerProxy;
+
+var builder = DistributedApplication.CreateBuilder(args);
 
 var grafana = builder.AddContainer("grafana", "grafana/grafana")
                      .WithBindMount("../grafana/config", "/etc/grafana", isReadOnly: true)
                      .WithBindMount("../grafana/dashboards", "/var/lib/grafana/dashboards", isReadOnly: true)
                      .WithHttpEndpoint(targetPort: 3000, name: "http");
 
 builder.AddProject<Projects.MetricsApp>("app")
-       .WithEnvironment("GRAFANA_URL", grafana.GetEndpoint("http"));
+       .WithEnvironment("GRAFANA_URL", grafana.GetEndpoint("http"))
+       .WithContainerProxy();
 
 builder.AddContainer("prometheus", "prom/prometheus")
        .WithBindMount("../prometheus", "/etc/prometheus", isReadOnly: true)

samples/Metrics/prometheus/prometheus.yml

@@ -1,7 +1,7 @@
 global:
-  scrape_interval: 1s # makes for a good demo
+  scrape_interval: 5s # makes for a good demo
 
 scrape_configs:
   - job_name: 'metricsapp'
     static_configs:
-      - targets: ['host.docker.internal:5048'] # hard-coded port matches launchSettings.json
+      - targets: ['app']