logging

Overview ¶

Package logging configures process-wide structured logging for GoatFlow.

It honours three environment variables (documented in .env.example):

LOG_FORMAT=json|text     — output format (default: text)
LOG_LEVEL=debug|info|warn|error — minimum level for slog (default: info)
LOG_OUTPUT=stdout|<path> — where logs are written (default: stdout).
LOG_FILE_PATH=<path>     — legacy alias: used as the destination when
                           LOG_OUTPUT is unset/empty, so existing
                           deployments keep their log file.

Two log sinks are configured so the whole codebase behaves consistently:

1. slog — a level-aware JSON or Text handler becomes the default logger (slog.SetDefault), so every slog.* call in the codebase is structured.
2. stdlib log — legacy log.Printf call sites are routed through a format-aware writer, so they respect the same LOG_FORMAT and LOG_OUTPUT. In JSON mode each line goes through the slog JSON handler, so both kinds of record share one layout ("level":"INFO" etc.). stdlib log carries no level metadata, so its lines are always emitted at INFO; only slog lines are filtered by LOG_LEVEL.