Log DCP messages at Debug/Trace level in AppHost

[Copilot]

DCP errors now flow to resources and are displayed in resource context. AppHost should not duplicate these logs at their original severity levels (Error/Warning/Info), creating console noise.

Changes

Modified DcpHost.LogSocketOutputAsync to map all DCP log levels to Debug/Trace:

• DCP Error/Warning/Info/Debug → AppHost Debug
• DCP Trace → AppHost Trace
• Unparseable logs → AppHost Debug (was Information)

// Map DCP log levels to Debug/Trace to reduce noise in AppHost output.
// DCP errors are now flowing to resources and can be hidden from output,
// so we log them at Debug/Trace level instead of using the original DCP log level.
var appHostLogLevel = logLevel == LogLevel.Trace ? LogLevel.Trace : LogLevel.Debug;

Added test TryParseDcpLog_ParsesAllLogLevels to validate parser handles all DCP log levels.

Impact

DCP diagnostics are hidden from AppHost console by default. Users can enable Debug/Trace logging if needed. Resource-specific DCP errors remain visible in resource context.

Original prompt

We're flowing DCP errors to resources and now we can hide them from the output.

aspire/src/Aspire.Hosting/Dcp/DcpHost.cs

Line 265 in 2717f1b

private async Task LogSocketOutputAsync(Socket socket, CancellationToken cancellationToken)

We should make these debug/trace level by default in the apphost ignoring the log level from dcp.

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[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/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.sh | bash -s -- 12533

Or

• Run remotely in PowerShell:

iex "& { $(irm https://raw.githubusercontent.com/dotnet/aspire/main/eng/scripts/get-aspire-cli-pr.ps1) } 12533"

[Copilot]

Pull Request Overview

This PR reduces the verbosity of DCP (Distributed Container Platform) logs in the AppHost output by downgrading all DCP log levels to Debug or Trace. The change acknowledges that DCP errors now flow to resources and can be filtered out, so they no longer need to be logged at their original severity levels in the AppHost output.

• Changes DCP log level mapping to always use Debug (or Trace for Trace-level logs) instead of the original log level
• Updates fallback logging for unparseable DCP logs from Information to Debug
• Adds comprehensive test coverage using Theory pattern to verify all log levels are correctly parsed

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
src/Aspire.Hosting/Dcp/DcpHost.cs	Maps all DCP log levels to Debug/Trace to reduce noise, adds explanatory comment about the change
tests/Aspire.Hosting.Tests/Dcp/DcpLogParserTests.cs	Adds parameterized test to verify parser handles all log levels correctly

[davidfowl]

/backport to release/13.0

[github-actions]

Started backporting to release/13.0: https://github.com/dotnet/aspire/actions/runs/18993029761