ln-771-logging-configurator

SKILL.md

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