Add WithVolumeMount Extension Method to Container Resource Class

samples/eShopLite/AppHost/Program.cs

@@ -1,14 +1,21 @@
 var builder = DistributedApplication.CreateBuilder(args);
 
-var catalogDb = builder.AddPostgres("postgres").AddDatabase("catalogdb");
+var catalogDb = builder.AddPostgresContainer("postgres")
+                       .WithNamedVolume("VolumeMount.example.data");
 
-var basketCache = builder.AddRedis("basketcache");
+// Add another Postgres container with the same named volume to see if named volumes name validation works correctly
+builder.AddPostgresContainer("randomdb")
+       .WithNamedVolume("VolumeMount.example.data");
+
+var basketCache = builder.AddRedisContainer("basketcache")
+                         .WithNamedVolume("basketcachvolume");
 
 var catalogService = builder.AddProject<Projects.CatalogService>("catalogservice")
                      .WithReference(catalogDb)
                      .WithReplicas(2);
 
-var messaging = builder.AddRabbitMQ("messaging");
+var messaging = builder.AddRabbitMQContainer("messaging")
+                       .WithNamedVolume("messagingvolume");
 
 var basketService = builder.AddProject("basketservice", @"..\BasketService\BasketService.csproj")
                     .WithReference(basketCache)

src/Aspire.Hosting/Dcp/ApplicationExecutor.cs

@@ -509,12 +509,66 @@ private void PrepareContainers()
                 }
             }
 
+            // Ensure no duplicate target volumes are mounted.
+            ValidateNamedVolumes(ctr);
+
             var containerAppResource = new AppResource(container, ctr);
             AddServicesProducedInfo(container, ctr, containerAppResource);
             _appResources.Add(containerAppResource);
         }
     }
 
+    private static void ValidateNamedVolumes(Container? container)
+    {
+
+        if(container is null)
+        {
+            return;
+        }
+
+        var volumeList = container.Spec.VolumeMounts;
+
+        if(volumeList is null)
+        {
+            return;
+        }
+
+        if(volumeList.Count == 0)
+        {
+            return;
+        }
+
+        var volumeNameToMountCount = new Dictionary<string, int>();
+
+        var namedVolumes = volumeList.Where(v => v.Type == Model.VolumeMountType.Named).ToArray();
+
+        foreach(VolumeMount namedVolume in namedVolumes)
+        {
+            if(namedVolume.Source is null)
+            {
+                continue;
+            }
+
+            if(volumeNameToMountCount.TryGetValue(namedVolume.Source, out var value))
+            {
+                volumeNameToMountCount[namedVolume.Source] = ++value;
+            }
+            else
+            {
+                volumeNameToMountCount.Add(namedVolume.Source, 1);
+            }
+        }
+
+        foreach(var volumeName in volumeNameToMountCount.Keys)
+        {
+            if (volumeNameToMountCount[volumeName] > 1)
+            {
+                throw new InvalidOperationException($"Volume {volumeName} is mounted more than once in container {container.Metadata.Name}");
+            }
+        }
+
+    }
+
     private async Task CreateContainersAsync(IEnumerable<AppResource> containerResources, CancellationToken cancellationToken)
     {
         try

src/Aspire.Hosting/Extensions/ContainerResourceBuilderExtensions.cs

@@ -83,6 +83,31 @@ public static IResourceBuilder<T> WithVolumeMount<T>(this IResourceBuilder<T> bu
         return builder.WithAnnotation(annotation);
     }
 
+    public static IResourceBuilder<T> WithNamedVolume<T>(this IResourceBuilder<T> builder, string volumeName) where T : ContainerResource
+    {
+        ArgumentNullException.ThrowIfNullOrWhiteSpace(volumeName, nameof(volumeName));
+
+        // Mapping of parent resource types to their volume paths
+        var volumePaths = new Dictionary<Type, string>
+        {
+            { typeof(SqlServerContainerResource), "/var/opt/mssql" },
+            { typeof(MongoDBContainerResource), "/data/db" },
+            { typeof(RedisContainerResource), "/data" },
+            { typeof(PostgresContainerResource), "/var/lib/postgresql/data" },
+            { typeof(RabbitMQContainerResource), "/var/lib/rabbitmq" },
+            { typeof(MySqlContainerResource), "/var/lib/mysql" }
+        };
+
+        Type resourceType = typeof(T);
+
+        if (volumePaths.TryGetValue(resourceType, out var volumePath))
+        {
+            builder.WithVolumeMount(volumeName, volumePath, VolumeMountType.Named);
+        }
+
+        return builder;
+    }
+
     /// <summary>
     /// Adds the arguments to be passed to a container resource when the container is started.
     /// </summary>