logutil

Overview ¶

Package logutil provides a structured logging abstraction built on top of slog.

This package provides a simple, consistent logging interface for azd extensions. It wraps the standard library's slog package with convenience functions and environment-aware configuration.

Basic Usage ¶

// Initialize logging (typically in main.go)
logutil.SetupLogger(debug, structured)

// Log messages at different levels
logutil.Debug("processing item", "id", itemID)
logutil.Info("operation completed", "duration", elapsed)
logutil.Warn("deprecated feature used", "feature", name)
logutil.Error("operation failed", "error", err)

Debug Mode ¶

Debug logging can be enabled in two ways:

• Pass debug=true to SetupLogger
• Set the AZD_DEBUG environment variable to a truthy value

AZD_DEBUG accepts anything strconv.ParseBool accepts, plus "yes", matching the azd extension framework. Unlike the level set through SetupLogger or SetLevel, it is consulted on every call, so it can be flipped at runtime.

Structured Logging ¶

When structured=true is passed to SetupLogger, logs are output as JSON:

{"time":"2024-01-15T10:30:00Z","level":"INFO","msg":"operation completed","duration":"1.5s"}

Otherwise, logs use a human-readable text format:

time=2024-01-15T10:30:00Z level=INFO msg="operation completed" duration=1.5s

Component loggers ¶

NewLogger returns a ComponentLogger that tags every line with a component name and supports chaining service, operation, and arbitrary fields:

log := logutil.NewLogger("deploy").WithService("api").WithOperation("push")
log.Info("starting", "revision", rev)

ComponentLogger wraps azdext.Logger and exposes it through AzdextLogger, so a logger created here can be handed to any SDK API that expects one.

Relationship to azdext ¶

Setup delegates to azdext.SetupLogging, but level filtering and the output writer are handled here rather than by the SDK, for two reasons.

azdext.LoggerOptions carries a single Debug boolean, so it can express only debug and info. Delegating the filter would make SetLevel(LevelWarn) and SetLevel(LevelError) silently ineffective.

azdext.NewLogger constructs a fresh handler and defaults to stderr rather than inheriting slog.Default, contrary to its documentation. This package passes the configured writer explicitly; without that, SetOutput would be a no-op for component loggers and their output would leak to stderr.

A ComponentLogger captures the writer and format in effect when it is constructed, so configure logging before creating loggers you intend to capture.