logger

mod/logger

mod/logger builds the process logger from configuration. It wires console output, rotating file output, and optional VictoriaLogs shipping into one logger used by runtime packages.

Place in the runtime

flowchart TB
  config["stconf config"] --> logger["mod/logger"]
  logger --> console["console sink"]
  logger --> file["rotating file sink"]
  logger --> remote["VictoriaLogs sink"]
  runtime["runtime packages"] --> logger

Responsibilities

• Build a structured logger from logging.* config.
• Normalize sink levels and disabled sinks.
• Configure log file rotation limits.
• Keep user-facing log messages in English.
• Provide a no-surprise logger for startup, runtime, and maintenance commands.

Contracts

• Logger construction should not start the main runtime.
• A disabled sink must not allocate background workers.
• Remote logging failures must not crash the mirror. They are operational degradation, not data corruption.
• Logs should use stable, low-cardinality fields such as component, key, version, and request id.

Important files

• obj.go: logger construction and sink selection.
• helper.go: sink helpers and level parsing.
• victorialogs.go: VictoriaLogs sink delivery.

Operational notes

Use file logging for persistent node diagnostics. Console logging is usually enough for containers. VictoriaLogs is optional and should be treated as best-effort telemetry.