Fix HostUrl with container tunnel

[David Negstad (danegsta)]

Description

Fixes #16641
Fixes #16642

This fixes HostUrl resolution for container resources when the Aspire container tunnel is enabled.

• Treat HostUrl values that match an app-model host endpoint as dependencies so DCP creates the corresponding container tunnel service before the container environment is resolved.
• Resolve matching HostUrl values through the endpoint reference's async port property instead of reading the endpoint's allocated port synchronously before tunnel allocation completes.
• Keep unmatched host-local HostUrl values on the container host bridge instead of rewriting them to aspire.dev.internal when no tunnel service backs that port.
• Add DCP-level regression tests for both matching and unmatched HostUrl host-port scenarios.

Validation:

• dotnet test --project tests/Aspire.Hosting.Tests/Aspire.Hosting.Tests.csproj --no-launch-profile -- --filter-method "*.ContainerHostUrlMatchingHostEndpointUsesTunnelPort" --filter-method "*.ContainerHostUrlWithoutMatchingHostEndpointUsesContainerHostBridge" --filter-method "*.HostUrlPropertyGetsResolved" --filter-method "*.HostUrlPropertyGetsResolvedInOtlpExporterEndpoint" --filter-not-trait "quarantined=true" --filter-not-trait "outerloop=true"
• dotnet test --project tests/Aspire.Hosting.Tests/Aspire.Hosting.Tests.csproj --no-launch-profile -- --filter-class "*.DcpExecutorTests" --filter-not-trait "quarantined=true" --filter-not-trait "outerloop=true"

Checklist

• Is this feature complete?
  • Yes. Ready to ship.
  • No. Follow-up changes expected.
• Are you including unit tests for the changes and scenario tests if relevant?
  • Yes
  • No
• Did you add public API?
  • Yes
    • If yes, did you have an API Review for it?
      • Yes
      • No
    • Did you add <remarks /> and <code /> elements on your triple slash comments?
      • Yes
      • No
  • No
• Does the change make any security assumptions or guarantees?
  • Yes
    • If yes, have you done a threat model and had a security review?
      • Yes
      • No
  • No
• Does the change require an update in our Aspire docs?
  • Yes
    • Link to aspire.dev issue:
      • New issue
  • No

[github-actions]

🚀 Dogfood this PR with:

⚠️ WARNING: Do not do this without first carefully reviewing the code of this PR to satisfy yourself it is safe.

curl -fsSL https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 16684

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/microsoft/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 16684"

[Copilot]

Pull request overview

This PR fixes HostUrl resolution for container resources when the Aspire container tunnel is enabled, ensuring HostUrl values that correspond to app-model host endpoints are resolved via the tunnel (including async port allocation), while unmatched host-local URLs remain on the container host bridge.

Changes:

• Update HostUrl resolution to (a) detect localhost targets robustly, (b) resolve matching host endpoints via the tunnel using the endpoint’s async Port property, and (c) keep unmatched host-local URLs on the host bridge hostname.
• Treat matching HostUrl values as dependencies during dependency discovery so tunnel services are created before container environment evaluation.
• Add/adjust regression tests covering both the “matching host endpoint uses tunnel port” and “unmatched host-local port uses host bridge” scenarios.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 2 comments.

File	Description
tests/Aspire.Hosting.Tests/ExpressionResolverTests.cs	Updates expectations for HostUrl rewriting when tunnel is enabled but no matching app-model host endpoint exists.
tests/Aspire.Hosting.Tests/Dcp/DcpExecutorTests.cs	Adds DCP regression tests for matched vs. unmatched HostUrl host-port behavior and updates test executor DI setup.
src/Aspire.Hosting/ApplicationModel/ResourceExtensions.cs	Extends dependency discovery to treat certain HostUrl values as resource dependencies.
src/Aspire.Hosting/ApplicationModel/HostUrl.cs	Updates HostUrl resolution logic to support container tunnel port allocation and adds localhost/port parsing helper.

[David Negstad (danegsta)]

/backport to release/13.3

[github-actions]

Started backporting to release/13.3 (link to workflow run)