OpenTelemetryCollector fails to export due to DNS issues

[dosolkowski-work]

Describe the bug

The OTel collector provided by CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector fails to export anything back to Aspire because it cannot resolve aspire.dev.internal via DNS.

Regression

No response

Steps to reproduce

• Add the CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector package to an Aspire AppHost project.
• Add the collector to the AppHost using builder.AddOpenTelemetryCollector("otel-collector").WithConfig("config.yaml"); where config.yaml is the example configuration. I have also tried including .WithOtlpExporter(OtlpProtocol.Grpc) and that did not help.
• The collector starts reporting errors:

2026-09-01T13:40:49.730Z	warn	grpc@v1.83.0/resolver_wrapper.go:157	[core] [Channel #1] ccResolverWrapper: reporting error to cc: dns: A record lookup error: lookup aspire.dev.internal on 10.89.1.1:53: dial udp 10.89.1.1:53: i/o timeout	{"resource": {"service.instance.id": "fd5d7e94-490d-46e1-853e-d89d458eac81", "service.name": "otelcol-contrib", "service.version": "0.159.0"}, "grpc_log": true}

Expected behavior

The OTel collector is able to collect OpenTelemetry data and forward it to Aspire.

Screenshots

No response

IDE and version

Other

IDE version

Visual Studio 2026 v18.9.2

Nuget packages

CommunityToolkit.Aspire.Hosting.OpenTelemetryCollector v13.5.0

Additional context

No response

Help us help you

Yes, but only if others can assist

[dosolkowski-work]

It seems like the problem is related to how the URL is obtained, by trying to parse configuration instead of using an endpoint reference. However, maybe instead of trying to create a custom ASPIRE_ENDPOINT environment variable, the collector configuration can just reference the default OTEL_EXPORTER_OTLP_ENDPOINT variable?