contextlogger

Go's Context Logger

ContextLogger implements contextual logging using slog by embedding itself into context.Context's. Making it effortless to maintain consistent log context throughout your application's call stack.

It has the following features:

• Context-Embedded Logging - Logger travels with your context.Context, eliminating manual logger passing
• slog Familiarity - Built on top of Go's standard log/slog package with a familiar API
• Structured Logging - Support for key-value pairs and nested groups for organized log output
• Highly Configurable - Customize log levels, handlers, formatters, and output destinations
• Middleware Ready - Built-in HTTP middleware for automatic request logging, and more coming soon!
• Multiple Handlers - Support for JSON, text, and custom log formats. Basically, everything that slog supports
• Performance Focused - Minimal overhead with efficient context propagation

Why use Context Logger?

Traditional logging often requires passing a logger instance through your entire call stack or using a global logger that lacks request-specific context. Context Logger solves this by:

1. Embedding the logger in context - Access your logger anywhere you have a context.Context
2. Automatic context accumulation - Build up contextual information as requests flow through layers
3. Cleaner function signatures - No need to pass logger as a parameter to every function

Installation

Use go get:

go get github.com/pablovarg/contextlogger

Then import the contextlogger package into your code:

import "github.com/pablovarg/contextlogger"

Usage

ctx := context.Background()

// Embed a logger into the context
ctx = contextlogger.EmbedLogger(ctx)

// Update the stored context
contextlogger.UpdateContext(ctx, "id", user.ID, "email", user.Email)

// Create groups for different parts of your code,
// and update the context as above inside this group
processUser(contextlogger.WithGroup(ctx, "userProcess"))

// To print the whole accumulated context
contextlogger.LogWithContext(ctx, slog.LevelInfo, "user information")

Examples

• Basic
• Custom Logger
• Groups
• HTTP Middleware

Contributing

This project is currently open to contributions from the community, some things you can work on:

• Support for different logging libraries
• Include a middleware for your favorite framework
• Anything else you can imagine