config

mod/config

mod/config loads and validates runtime configuration before any long-lived subsystem starts. Schema-level parsing is generated into target/stconf; this package adds file handling, preset loading, and business validation that depends on multiple config sections.

Place in the runtime

flowchart TB
  file["YAML, JSON, or HJSON"] --> config["mod/config"]
  presets["generated presets"] --> config
  config --> schema["target/stconf"]
  schema --> validation["business validation"]
  validation --> runtime["runtime assembly"]

Responsibilities

• Detect config format from the file extension.
• Decode YAML, JSON, and HJSON into generated config structs.
• Apply defaults and schema validation through target/stconf.
• Validate cross-section business rules such as listener modes, TLS pairs, static routing, profiling bind address, storage limits, and rate-limit budgets.
• Load generated presets for CLI commands.

Contracts

• A config is either valid before runtime assembly or the process exits with an English error.
• Validation must catch unsafe public pprof binds and inconsistent web listener settings.
• Generated files in target/stconf are source-of-truth for schema defaults and field documentation.
• Business validation should stay deterministic and should not perform network calls.

Important files

• init.go: generated parser entry and business-validation handoff.
• helper.go: shared patterns, reserved keys, and validation constants.
• validate.go: cross-section validation.
• config_test.go: format, default, and cross-section validation coverage.
• profiling_test.go: profiling-listener safety coverage.

Operational notes

When adding a new config field, update the schema in yml/config, regenerate target/stconf, and add business validation here only if the rule cannot be expressed in the schema.