microsoft/aspire · error · InvalidDataException

Host endpoint ' ' on resource ' ' should have an associated…

Error message

Host endpoint '{endpoint.Name}' on resource '{re.Resource.Name}' should have an associated DCP Service resource already set up

What it means

Before wiring host-resource endpoints into container networks, Aspire expects a matching DCP Service resource (per resource name + endpoint name) to have been created earlier. When none is found, an InvalidDataException is thrown - the endpoint/Service pre-setup step was skipped or ran out of order.

Solutions

Ensure the DCP Service creation step runs before container network setup for the resource
Verify endpoint names match exactly (case-sensitive) between the resource and its Service
Recreate/refresh the app model so Services are regenerated for all endpoints

Defensive patterns

Strategy: validation

Validate before calling

var svc = appResources.OfType<ServiceWithModelResource>().FirstOrDefault(s => StringComparers.ResourceName.Equals(s.ModelResource.Name, name) && StringComparers.EndpointAnnotationName.Equals(s.EndpointAnnotation.Name, endpointName)); if (svc is null) { /* run service setup first */ }

Try / catch

try { await networkSetup(re); } catch (InvalidDataException ex) when (ex.Message.Contains("DCP Service resource")) { logger.LogError(ex, "Service for endpoint {Endpoint} missing; run service generation first", endpointName); }

Prevention

Run the DCP Service creation step before container network wiring
Keep endpoint names stable after initial model build
In custom pipelines, follow the built-in prepare-then-create ordering

When it happens

Trigger: CreateContainerNetworkServicesForHostResource processes a HostResourceWithEndpoints whose endpoint name has no ServiceWithModelResource with the same model resource name and endpoint annotation name in _appResources.

Common situations: Custom pipelines or eventing that create host resources without running the Service setup step, endpoint renamed/added after services were generated, or interacting with container-network features out of order in custom code.

Understand the failure class

Background: 'Could not be found', 'does not exist', 'not found in database': the resource-not-found family when an ID, slug, key, or URI lookup comes back empty — this error's family across 20 libraries.

Related errors

AI-assisted analysis of microsoft/aspire@25830f84bd (2026-09-16). Data as JSON: /api/errors/0a4e8270d119d8ff. Report an issue: GitHub.

Appendix: source

Thrown at src/Aspire.Hosting/Dcp/ContainerCreator.cs:447

            }

            if (useTunnel && endpoint.Protocol != ProtocolType.Tcp)
            {
                resourceLogger.LogWarning("Host endpoint '{EndpointName}' on resource '{HostResource}' is referenced by a container resource, but the endpoint is using a network protocol '{Protocol}' other than TCP. Only TCP is supported for container-to-host references.", endpoint.Name, re.Resource.Name, endpoint.Protocol);
                continue;
            }

            var svc = Service.Create(serviceName);
            svc.Spec.AddressAllocationMode = AddressAllocationModes.Proxyless;
            svc.Spec.Protocol = PortProtocol.FromProtocolType(endpoint.Protocol);

            var serverSvc = _appResources.Get().OfType<ServiceWithModelResource>().FirstOrDefault(swr =>
                StringComparers.ResourceName.Equals(swr.ModelResource.Name, re.Resource.Name) &&
                StringComparers.EndpointAnnotationName.Equals(swr.EndpointAnnotation.Name, endpoint.Name)
            );
            if (serverSvc is null)
            {
                throw new InvalidDataException($"Host endpoint '{endpoint.Name}' on resource '{re.Resource.Name}' should have an associated DCP Service resource already set up");
            }

            TunnelConfiguration? tunnelConfig = null;
            if (useTunnel)
            {
                tunnelConfig = new TunnelConfiguration
                {
                    Name = serviceName,
                    ServerServiceName = serverSvc.DcpResource.Metadata.Name,
                    ServerServiceNamespace = string.Empty,
                    ClientServiceName = svc.Metadata.Name,
                    ClientServiceNamespace = string.Empty
                };
            }

            svc.Annotate(CustomResource.ResourceNameAnnotation, re.Resource.Name);
            svc.Annotate(CustomResource.EndpointNameAnnotation, endpoint.Name);
            svc.Annotate(CustomResource.ContainerNetworkAnnotation, KnownNetworkIdentifiers.DefaultAspireContainerNetwork.Value);

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