ln-771-logging-configurator

Type: L3 Worker Category: 7XX Project Bootstrap

Configures structured JSON logging for .NET and Python projects.

Overview

Aspect Details

Input Context Store from ln-770

Output Logging configuration files

Stacks .NET (Serilog), Python (structlog)

Phase 1: Receive Context

Accept Context Store from coordinator.

Required Context:

• STACK : .NET or Python

• FRAMEWORK : ASP.NET Core or FastAPI

• FRAMEWORK_VERSION : Version number

• PROJECT_ROOT : Project directory path

• ENVIRONMENT : Development or Production

Validation:

• If STACK not provided, detect from project files

• If version not provided, use latest stable

Phase 2: Research Current Best Practices

Use MCP tools to get up-to-date documentation.

For .NET (Serilog):

MCP ref: "Serilog ASP.NET Core structured logging configuration" Context7: /serilog/serilog-aspnetcore

For Python (structlog):

MCP ref: "structlog Python structured logging configuration" Context7: /hynek/structlog

Key Patterns to Research:

• Request logging middleware

• Log enrichment (correlation ID, user context)

• Log level configuration by environment

• Sink configuration (Console, File, Seq, Elastic)

Phase 3: Decision Points

Ask user for configuration preferences.

Q1: Log Format

Option When to Use

JSON (Recommended for Production) Machine-readable, log aggregation systems

Pretty/Colored (Recommended for Development) Human-readable, local debugging

Q2: Enrichment Fields

Field Description Default

correlationId

Request tracking across services ✓ Yes

userId

Authenticated user identifier ✓ Yes

requestPath

HTTP request path ✓ Yes

responseTime

Request duration in ms ✓ Yes

machineName

Server hostname Optional

threadId

Thread identifier Optional

Q3: Log Sinks

Sink Use Case

Console Always enabled

File Local persistence, log rotation

Seq Structured log server

Elasticsearch Log aggregation at scale

Q4: Log Levels by Environment

Level Development Production

Default Debug Information

Microsoft.* Information Warning

System.* Information Warning

Application Debug Information

Phase 4: Generate Configuration

Generate files based on stack and decisions.

.NET Output Files

File Purpose

Extensions/LoggingExtensions.cs

Service registration

appsettings.json (update) Serilog configuration

appsettings.Development.json (update) Dev overrides

Generation Process:

• Use MCP ref to get current Serilog API

• Generate LoggingExtensions.cs with:

• UseSerilog configuration

• Request logging middleware

• Enrichment configuration

• Update appsettings.json with Serilog section

Packages to Add:

• Serilog.AspNetCore

• Serilog.Sinks.Console

• Serilog.Sinks.File (if File sink selected)

• Serilog.Enrichers.Environment (if machineName selected)

Python Output Files

File Purpose

core/logging_config.py

structlog configuration

middleware/logging_middleware.py

Request logging

Generation Process:

• Use MCP ref to get current structlog API

• Generate logging_config.py with:

• Processor chain configuration

• Renderer selection (JSON/Console)

• Log level configuration

• Generate logging_middleware.py for FastAPI

Packages to Add:

• structlog

• python-json-logger (if JSON format)

Phase 5: Validate

Verify the configuration works.

Validation Steps:

Check imports: Ensure all packages are available

• .NET: dotnet list package | grep Serilog

• Python: pip list | grep structlog

Syntax check:

• .NET: dotnet build --no-restore

• Python: python -m py_compile core/logging_config.py

Test log output:

• Start application

• Make test request

• Verify log format matches configuration

Expected Log Format:

{ "timestamp": "2026-01-10T12:00:00.000Z", "level": "info", "message": "Request completed", "correlationId": "abc-123", "requestPath": "/api/health", "responseTime": 45, "statusCode": 200 }

Return to Coordinator

Return result to ln-770:

{ "status": "success", "files_created": [ "Extensions/LoggingExtensions.cs", "appsettings.json" ], "packages_added": [ "Serilog.AspNetCore", "Serilog.Sinks.Console" ], "registration_code": "services.AddLoggingServices(configuration);", "message": "Configured structured logging with Serilog" }

Idempotency

This skill is idempotent:

• Phase 1: Check if logging already configured (Grep for Serilog/structlog)

• If configured: Return { "status": "skipped", "message": "Logging already configured" }

• If not: Proceed with configuration

Reference Links

• Serilog.AspNetCore

• structlog Documentation

• ASP.NET Core Logging

Critical Rules

• Use MCP ref/Context7 for current API — do not hardcode Serilog/structlog config from memory

• Idempotent — if Serilog or structlog already configured, return status: "skipped" immediately

• Environment-aware log levels — Debug for Development, Information for Production (never Warning default)

• Always include correlation ID enrichment — required for distributed tracing

• Return structured response — files_created , packages_added , registration_code for coordinator aggregation

Definition of Done

• Context Store received and validated (stack, framework, version)

• Best practices researched via MCP tools for target stack

• User decisions collected (format, enrichment, sinks, log levels)

• Configuration files generated (extensions/config + appsettings or Python modules)

• Syntax validated (dotnet build or py_compile )

• Structured JSON response returned to ln-770 coordinator

Version: 2.0.0 Last Updated: 2026-01-10