go.nownabe.dev/clog

clog is a structured logger optimized for Cloud Logging based on log/slog.

clog supports following special fields in JSON log entries:

• severity
• message
• httpRequest
• time
• logging.googleapis.com/insertId
• logging.googleapis.com/labels
• logging.googleapis.com/operation
• logging.googleapis.com/sourceLocation
• logging.googleapis.com/spanId
• logging.googleapis.com/trace
• logging.googleapis.com/trace_sampled
• logging.googleapis.com/stack_trace

See Cloud Logging documentation and Cloud Error Reporting documentation for more details.

Severity

clog uses Severity in the severity field instead of log levels. 8 severities are supported:

• DEBUG
• INFO
• NOTICE
• WARNING
• ERROR
• CRITICAL
• ALERT
• EMERGENCY

Usage

Each severity has three methods like Info, Infof, and InfoErr.

clog.Info(ctx, "simple logging with args", "key", "value")
// {"severity":"INFO", "message":"simple logging with args", "key":"value",
//  "time": "...", "logging.googleapis.com/sourceLocation": {...}}

clog.Noticef(ctx, "formatted message %s %s", "like", "fmt.Printf")
// {"severity":"NOTICE", "message":"formatted message like fmt.Printf",
//  "time": "...", "logging.googleapis.com/sourceLocation": {...}}

clog.CriticalErr(ctx, errors.New("critical error!!"), "key", "value")
// {"severity":"CRITICAL", "message":"critical error!!", "key":"value",
//  "time": "...", "logging.googleapis.com/sourceLocation": {...}}

// clog.ErrorErr has a shorthand clog.Err.
clog.Err(ctx, errors.New("error!"))
// {"severity":"ERROR", "message":"error!",
//  "time": "...", "logging.googleapis.com/sourceLocation": {...}}

See Examples for more details.