Mark ParameterResource.Value as obsolete in favor of GetValueAsync and direct usage

src/Aspire.Hosting.Azure/AzurePublishingContext.cs

@@ -117,9 +117,9 @@ private async Task WriteAzureArtifactsOutputAsync(IPublishingStep step, Distribu
             .Where(r => !r.IsExcludedFromPublish())
             .ToList();
 
-        MapParameter(environment.ResourceGroupName);
-        MapParameter(environment.Location);
-        MapParameter(environment.PrincipalId);
+        await MapParameterAsync(environment.ResourceGroupName, cancellationToken).ConfigureAwait(false);
+        await MapParameterAsync(environment.Location, cancellationToken).ConfigureAwait(false);
+        await MapParameterAsync(environment.PrincipalId, cancellationToken).ConfigureAwait(false);
 
         var resourceGroupParam = ParameterLookup[environment.ResourceGroupName];
         MainInfrastructure.Add(resourceGroupParam);
@@ -163,14 +163,14 @@ private async Task WriteAzureArtifactsOutputAsync(IPublishingStep step, Distribu
             // Map parameters from existing resources
             if (resource.TryGetLastAnnotation<ExistingAzureResourceAnnotation>(out var existingAnnotation))
             {
-                Visit(existingAnnotation.ResourceGroup, MapParameter);
-                Visit(existingAnnotation.Name, MapParameter);
+                await VisitAsync(existingAnnotation.ResourceGroup, MapParameterAsync, cancellationToken).ConfigureAwait(false);
+                await VisitAsync(existingAnnotation.Name, MapParameterAsync, cancellationToken).ConfigureAwait(false);
             }
 
             // Map parameters for the resource itself
             foreach (var parameter in resource.Parameters)
             {
-                Visit(parameter.Value, MapParameter);
+                await VisitAsync(parameter.Value, MapParameterAsync, cancellationToken).ConfigureAwait(false);
             }
         }
 
@@ -359,7 +359,7 @@ await task.SucceedAsync(
         }
     }
 
-    private void MapParameter(object? candidate)
+    private async Task MapParameterAsync(object candidate, CancellationToken cancellationToken = default)
     {
         if (candidate is ParameterResource p && !ParameterLookup.ContainsKey(p))
         {
@@ -372,7 +372,11 @@ private void MapParameter(object? candidate)
 
             if (!p.Secret && p.Default is not null)
             {
-                pp.Value = p.Value;
+                var value = await p.GetValueAsync(cancellationToken).ConfigureAwait(false);
+                if (value is not null)
+                {
+                    pp.Value = value;
+                }
             }
 
             ParameterLookup[p] = pp;
@@ -400,6 +404,27 @@ private static void Visit(object? value, Action<object> visitor, HashSet<object>
         }
     }
 
+    private static Task VisitAsync(object? value, Func<object, CancellationToken, Task> visitor, CancellationToken cancellationToken = default) =>
+        VisitAsync(value, visitor, [], cancellationToken);
+
+    private static async Task VisitAsync(object? value, Func<object, CancellationToken, Task> visitor, HashSet<object> visited, CancellationToken cancellationToken = default)
+    {
+        if (value is null || !visited.Add(value))
+        {
+            return;
+        }
+
+        await visitor(value, cancellationToken).ConfigureAwait(false);
+
+        if (value is IValueWithReferences vwr)
+        {
+            foreach (var reference in vwr.References)
+            {
+                await VisitAsync(reference, visitor, visited, cancellationToken).ConfigureAwait(false);
+            }
+        }
+    }
+
     /// <summary>
     /// Saves the compiled Bicep template to disk.
     /// </summary>

src/Aspire.Hosting.Docker/DockerComposePublishingContext.cs

@@ -155,7 +155,15 @@ private async Task WriteDockerComposeOutputAsync(DistributedApplicationModel mod
 
                     foreach (var entry in environment.CapturedEnvironmentVariables ?? [])
                     {
-                        var (key, (description, defaultValue, _)) = entry;
+                        var (key, (description, defaultValue, source)) = entry;
+
+                        // If the source is a parameter and there's no explicit default value,
+                        // resolve the parameter's default value asynchronously
+                        if (defaultValue is null && source is ParameterResource parameter && !parameter.Secret && parameter.Default is not null)
+                        {
+                            defaultValue = await parameter.GetValueAsync(cancellationToken).ConfigureAwait(false);
+                        }
+
                         envFile.AddIfMissing(key, defaultValue, description);
                     }
 

src/Aspire.Hosting.Docker/DockerComposeServiceExtensions.cs

@@ -98,7 +98,7 @@ public static string AsEnvironmentPlaceholder(this ParameterResource parameter,
         return dockerComposeService.Parent.AddEnvironmentVariable(
             env,
             description: $"Parameter {parameter.Name}",
-            defaultValue: parameter.Secret || parameter.Default is null ? null : parameter.Value,
+            defaultValue: null,
             source: parameter
         );
     }

src/Aspire.Hosting.Kubernetes/KubernetesPublishingContext.cs

@@ -80,22 +80,22 @@ private async Task WriteKubernetesOutputAsync(DistributedApplicationModel model,
                 }
 
                 await WriteKubernetesTemplatesForResource(resource, serviceResource.GetTemplatedResources()).ConfigureAwait(false);
-                AppendResourceContextToHelmValues(resource, serviceResource);
+                await AppendResourceContextToHelmValuesAsync(resource, serviceResource).ConfigureAwait(false);
             }
         }
 
         await WriteKubernetesHelmChartAsync(environment).ConfigureAwait(false);
         await WriteKubernetesHelmValuesAsync().ConfigureAwait(false);
     }
 
-    private void AppendResourceContextToHelmValues(IResource resource, KubernetesResource resourceContext)
+    private async Task AppendResourceContextToHelmValuesAsync(IResource resource, KubernetesResource resourceContext)
     {
-        AddValuesToHelmSection(resource, resourceContext.Parameters, HelmExtensions.ParametersKey);
-        AddValuesToHelmSection(resource, resourceContext.EnvironmentVariables, HelmExtensions.ConfigKey);
-        AddValuesToHelmSection(resource, resourceContext.Secrets, HelmExtensions.SecretsKey);
+        await AddValuesToHelmSectionAsync(resource, resourceContext.Parameters, HelmExtensions.ParametersKey).ConfigureAwait(false);
+        await AddValuesToHelmSectionAsync(resource, resourceContext.EnvironmentVariables, HelmExtensions.ConfigKey).ConfigureAwait(false);
+        await AddValuesToHelmSectionAsync(resource, resourceContext.Secrets, HelmExtensions.SecretsKey).ConfigureAwait(false);
     }
 
-    private void AddValuesToHelmSection(
+    private async Task AddValuesToHelmSectionAsync(
         IResource resource,
         Dictionary<string, KubernetesResource.HelmExpressionWithValue> contextItems,
         string helmKey)
@@ -114,7 +114,19 @@ private void AddValuesToHelmSection(
                 continue;
             }
 
-            paramValues[key] = helmExpressionWithValue.Value ?? string.Empty;
+            string? value;
+
+            // If there's a parameter source, resolve its value asynchronously
+            if (helmExpressionWithValue.ParameterSource is ParameterResource parameter)
+            {
+                value = await parameter.GetValueAsync(cancellationToken).ConfigureAwait(false);
+            }
+            else
+            {
+                value = helmExpressionWithValue.Value;
+            }
+
+            paramValues[key] = value ?? string.Empty;
         }
 
         if (paramValues.Count > 0)

src/Aspire.Hosting.Kubernetes/KubernetesResource.cs

@@ -311,10 +311,25 @@ private void ProcessEnvironmentDefaultValue(object value, string key, string res
         EnvironmentVariables[key] = new(configExpression, value.ToString() ?? string.Empty);
     }
 
-    internal class HelmExpressionWithValue(string helmExpression, string? value)
+    internal class HelmExpressionWithValue
     {
-        public string HelmExpression { get; } = helmExpression;
-        public string? Value { get; } = value;
+        public HelmExpressionWithValue(string helmExpression, string? value)
+        {
+            HelmExpression = helmExpression;
+            Value = value;
+            ParameterSource = null;
+        }
+
+        public HelmExpressionWithValue(string helmExpression, ParameterResource parameterSource)
+        {
+            HelmExpression = helmExpression;
+            Value = null;
+            ParameterSource = parameterSource;
+        }
+
+        public string HelmExpression { get; }
+        public string? Value { get; }
+        public ParameterResource? ParameterSource { get; }
         public bool IsHelmSecretExpression => HelmExpression.ContainsHelmSecretExpression();
         public bool ValueContainsSecretExpression => Value?.ContainsHelmSecretExpression() ?? false;
         public bool ValueContainsHelmExpression => Value?.ContainsHelmExpression() ?? false;

src/Aspire.Hosting.Kubernetes/KubernetesServiceResourceExtensions.cs

@@ -122,8 +122,15 @@ private static HelmExpressionWithValue AllocateParameter(ParameterResource param
             formattedName.ToHelmSecretExpression(resource.Name) :
             formattedName.ToHelmConfigExpression(resource.Name);
 
-        var value = parameter.Default is null || parameter.Secret ? null : parameter.Value;
-        return new(expression, value);
+        // Store the parameter itself for deferred resolution instead of resolving the value immediately
+        if (parameter.Default is null || parameter.Secret)
+        {
+            return new(expression, (string?)null);
+        }
+        else
+        {
+            return new(expression, parameter);
+        }
     }
 
     private static HelmExpressionWithValue ResolveUnknownValue(IManifestExpressionProvider parameter, IResource resource)

src/Aspire.Hosting/ApplicationModel/ParameterResource.cs

@@ -31,6 +31,10 @@ public ParameterResource(string name, Func<ParameterDefault?, string> callback,
     /// <summary>
     /// Gets the value of the parameter.
     /// </summary>
+    /// <remarks>
+    /// This property is obsolete. Use <see cref="GetValueAsync(CancellationToken)"/> for async access or pass the <see cref="ParameterResource"/> directly to methods that accept it (e.g., environment variables).
+    /// </remarks>
+    [Obsolete("Use GetValueAsync for async access or pass the ParameterResource directly to methods that accept it (e.g., environment variables).")]
     public string Value => GetValueAsync(default).AsTask().GetAwaiter().GetResult()!;
 
     internal string ValueInternal => _lazyValue.Value;

tests/Aspire.Hosting.Azure.Tests/AzureRedisExtensionsTests.cs

@@ -103,7 +103,9 @@ public async Task AddAzureRedisRunAsContainerProducesCorrectConnectionString()
         Assert.True(redis.Resource.IsContainer(), "The resource should now be a container resource.");
 
         Assert.NotNull(redisResource?.PasswordParameter);
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"localhost:12455,password={redisResource.PasswordParameter.Value}", await redis.Resource.ConnectionStringExpression.GetValueAsync(CancellationToken.None));
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
     [Fact]
@@ -195,7 +197,9 @@ public async Task PublishAsRedisPublishesRedisAsAzureRedisInfrastructure()
         Assert.True(redis.Resource.IsContainer());
         Assert.NotNull(redis.Resource.PasswordParameter);
 
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"localhost:12455,password={redis.Resource.PasswordParameter.Value}", await redis.Resource.GetConnectionStringAsync());
+#pragma warning restore CS0618 // Type or member is obsolete
 
         var manifest = await AzureManifestUtils.GetManifestWithBicep(redis.Resource);
 

tests/Aspire.Hosting.Milvus.Tests/MilvusFunctionalTests.cs

@@ -76,7 +76,9 @@ public async Task WithDataShouldPersistStateBetweenUsages(bool useVolume)
         {
             using var builder1 = TestDistributedApplicationBuilder.CreateWithTestContainerRegistry(testOutputHelper);
             var milvus1 = builder1.AddMilvus("milvus1");
+#pragma warning disable CS0618 // Type or member is obsolete
             var password = milvus1.Resource.ApiKeyParameter.Value;
+#pragma warning restore CS0618 // Type or member is obsolete
 
             var db1 = milvus1.AddDatabase("milvusdb1", dbname);
 

tests/Aspire.Hosting.MongoDB.Tests/AddMongoDBTests.cs

@@ -87,9 +87,13 @@ public async Task MongoDBCreatesConnectionString()
         Assert.NotNull(connectionStringResource);
         var connectionString = await connectionStringResource.GetConnectionStringAsync();
 
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"mongodb://admin:{dbResource.Parent.PasswordParameter?.Value}@localhost:27017?authSource=admin&authMechanism=SCRAM-SHA-256", await serverResource.GetConnectionStringAsync());
+#pragma warning restore CS0618 // Type or member is obsolete
         Assert.Equal("mongodb://admin:{mongodb-password.value}@{mongodb.bindings.tcp.host}:{mongodb.bindings.tcp.port}?authSource=admin&authMechanism=SCRAM-SHA-256", serverResource.ConnectionStringExpression.ValueExpression);
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"mongodb://admin:{dbResource.Parent.PasswordParameter?.Value}@localhost:27017/mydatabase?authSource=admin&authMechanism=SCRAM-SHA-256", connectionString);
+#pragma warning restore CS0618 // Type or member is obsolete
         Assert.Equal("mongodb://admin:{mongodb-password.value}@{mongodb.bindings.tcp.host}:{mongodb.bindings.tcp.port}/mydatabase?authSource=admin&authMechanism=SCRAM-SHA-256", connectionStringResource.ConnectionStringExpression.ValueExpression);
     }
 

tests/Aspire.Hosting.MongoDB.Tests/MongoDbFunctionalTests.cs

@@ -117,7 +117,9 @@ public async Task WithDataShouldPersistStateBetweenUsages(bool useVolume)
         {
             using var builder1 = TestDistributedApplicationBuilder.CreateWithTestContainerRegistry(testOutputHelper);
             var mongodb1 = builder1.AddMongoDB("mongodb");
+#pragma warning disable CS0618 // Type or member is obsolete
             var password = mongodb1.Resource.PasswordParameter!.Value;
+#pragma warning restore CS0618 // Type or member is obsolete
             var db1 = mongodb1.AddDatabase(dbName);
 
             if (useVolume)

tests/Aspire.Hosting.MySql.Tests/MySqlFunctionalTests.cs

@@ -129,7 +129,9 @@ public async Task WithDataShouldPersistStateBetweenUsages(bool useVolume)
             using var builder1 = TestDistributedApplicationBuilder.CreateWithTestContainerRegistry(testOutputHelper);
 
             var mysql1 = builder1.AddMySql("mysql").WithEnvironment("MYSQL_DATABASE", mySqlDbName);
+#pragma warning disable CS0618 // Type or member is obsolete
             var password = mysql1.Resource.PasswordParameter.Value;
+#pragma warning restore CS0618 // Type or member is obsolete
 
             var db1 = mysql1.AddDatabase(mySqlDbName);
 

tests/Aspire.Hosting.Nats.Tests/AddNatsTests.cs

@@ -39,7 +39,9 @@ public async Task AddNatsSetsDefaultUserNameAndPasswordAndIncludesThemInConnecti
             .WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 4222));
 
         Assert.NotNull(nats.Resource.PasswordParameter);
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.False(string.IsNullOrEmpty(nats.Resource.PasswordParameter!.Value));
+#pragma warning restore CS0618 // Type or member is obsolete
 
         using var app = appBuilder.Build();
 
@@ -50,7 +52,9 @@ public async Task AddNatsSetsDefaultUserNameAndPasswordAndIncludesThemInConnecti
         Assert.NotNull(connectionStringResource);
         var connectionString = await connectionStringResource.GetConnectionStringAsync();
 
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"nats://nats:{natsResource.PasswordParameter?.Value}@localhost:4222", connectionString);
+#pragma warning restore CS0618 // Type or member is obsolete
         Assert.Equal("nats://nats:{nats-password.value}@{nats.bindings.tcp.host}:{nats.bindings.tcp.port}", connectionStringResource.ConnectionStringExpression.ValueExpression);
     }
 
@@ -67,8 +71,10 @@ public async Task AddNatsSetsUserNameAndPasswordAndIncludesThemInConnection()
         Assert.NotNull(nats.Resource.UserNameParameter);
         Assert.NotNull(nats.Resource.PasswordParameter);
 
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal("usr", nats.Resource.UserNameParameter!.Value);
         Assert.Equal("password", nats.Resource.PasswordParameter!.Value);
+#pragma warning restore CS0618 // Type or member is obsolete
 
         using var app = appBuilder.Build();
 

tests/Aspire.Hosting.Oracle.Tests/OracleFunctionalTests.cs

@@ -94,7 +94,9 @@ public async Task WithDataShouldPersistStateBetweenUsages(bool useVolume)
 
             var oracle1 = builder1.AddOracle("oracle");
 
+#pragma warning disable CS0618 // Type or member is obsolete
             var password = oracle1.Resource.PasswordParameter.Value;
+#pragma warning restore CS0618 // Type or member is obsolete
 
             var db1 = oracle1.AddDatabase(oracleDbName);
 

tests/Aspire.Hosting.PostgreSQL.Tests/AddPostgresTests.cs

@@ -158,7 +158,9 @@ public async Task PostgresCreatesConnectionString()
 
         var connectionString = await connectionStringResource.GetConnectionStringAsync();
         Assert.Equal("Host={postgres.bindings.tcp.host};Port={postgres.bindings.tcp.port};Username=postgres;Password={postgres-password.value}", connectionStringResource.ConnectionStringExpression.ValueExpression);
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"Host=localhost;Port=2000;Username=postgres;Password={postgres.Resource.PasswordParameter.Value}", connectionString);
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
     [Fact]
@@ -491,7 +493,9 @@ public async Task WithPostgresProducesValidServersJsonFile()
         Assert.Equal("postgres", servers.GetProperty("1").GetProperty("Username").GetString());
         Assert.Equal("prefer", servers.GetProperty("1").GetProperty("SSLMode").GetString());
         Assert.Equal("postgres", servers.GetProperty("1").GetProperty("MaintenanceDB").GetString());
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"echo '{pg1.Resource.PasswordParameter.Value}'", servers.GetProperty("1").GetProperty("PasswordExecCommand").GetString());
+#pragma warning restore CS0618 // Type or member is obsolete
 
         // Make sure the second server is correct.
         Assert.Equal(pg2.Resource.Name, servers.GetProperty("2").GetProperty("Name").GetString());
@@ -501,7 +505,9 @@ public async Task WithPostgresProducesValidServersJsonFile()
         Assert.Equal("myuser", servers.GetProperty("2").GetProperty("Username").GetString());
         Assert.Equal("prefer", servers.GetProperty("2").GetProperty("SSLMode").GetString());
         Assert.Equal("postgres", servers.GetProperty("2").GetProperty("MaintenanceDB").GetString());
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"echo '{pg2.Resource.PasswordParameter.Value}'", servers.GetProperty("2").GetProperty("PasswordExecCommand").GetString());
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 
     [Fact]
@@ -619,6 +625,7 @@ public void CanAddDatabasesWithTheSameNameOnMultipleServers()
 
     private static string CreatePgWebBookmarkfileContent(PostgresDatabaseResource postgresDatabase)
     {
+#pragma warning disable CS0618 // Type or member is obsolete
         var user = postgresDatabase.Parent.UserNameParameter?.Value ?? "postgres";
 
         // We're hardcoding references to container resources based on a default Aspire network
@@ -631,6 +638,7 @@ private static string CreatePgWebBookmarkfileContent(PostgresDatabaseResource po
                 database = "{postgresDatabase.DatabaseName}"
                 sslmode = "disable"
                 """;
+#pragma warning restore CS0618 // Type or member is obsolete
 
         return fileContent;
     }
@@ -672,6 +680,8 @@ public async Task VerifyPostgresServerResourceWithUserName()
                                  .WithEndpoint("tcp", e => e.AllocatedEndpoint = new AllocatedEndpoint(e, "localhost", 2000));
 
         var connectionString = await postgres.Resource.GetConnectionStringAsync();
+#pragma warning disable CS0618 // Type or member is obsolete
         Assert.Equal($"Host=localhost;Port=2000;Username=user1;Password={postgres.Resource.PasswordParameter.Value}", connectionString);
+#pragma warning restore CS0618 // Type or member is obsolete
     }
 }