Imported from nineking424/etlmon (internal/config/AGENTS.md). Install upstream with npx skills add nineking424/etlmon --skill config. Copyright stays with the author.

config

Purpose

Configuration parsing for both Node and UI components. Loads and validates YAML configuration files.

Key Files

For AI Agents

Working In This Directory

• Use gopkg.in/yaml.v3 for YAML parsing
• Provide sensible defaults for all optional fields
• Validate configuration on load
• Return clear error messages for invalid config

Node Configuration

type NodeConfig struct {
    Node    NodeSettings    `yaml:"node"`
    Refresh RefreshSettings `yaml:"refresh"`
    Paths   []PathConfig    `yaml:"paths"`
    Logs    []LogConfig     `yaml:"logs"`
    Process ProcessConfig   `yaml:"process_watch"`
    Cron    CronConfig      `yaml:"cron"`
    Xferlog XferlogConfig   `yaml:"xferlog"`
}

type NodeSettings struct {
    Listen   string `yaml:"listen"`   // default: "0.0.0.0:8080"
    NodeName string `yaml:"node_name"`
    DBPath   string `yaml:"db_path"`  // default: "/var/lib/etlmon/etlmon.db"
}

type RefreshSettings struct {
    Disk            time.Duration `yaml:"disk"`             // default: 15s
    DefaultPathScan time.Duration `yaml:"default_path_scan"` // default: 5m
    Process         time.Duration `yaml:"process"`          // default: 5s
}

type PathConfig struct {
    Path         string        `yaml:"path"`
    ScanInterval time.Duration `yaml:"scan_interval"`
    MaxDepth     int           `yaml:"max_depth"`
    Exclude      []string      `yaml:"exclude"`
    Timeout      time.Duration `yaml:"timeout"`
}

UI Configuration

type UIConfig struct {
    Nodes []NodeEntry `yaml:"nodes"`
    UI    UISettings  `yaml:"ui"`
}

type NodeEntry struct {
    Name    string `yaml:"name"`
    Address string `yaml:"address"`
}

type UISettings struct {
    RefreshInterval time.Duration `yaml:"refresh_interval"` // default: 2s
    DefaultNode     string        `yaml:"default_node"`
}

Loading Pattern

func LoadNodeConfig(path string) (*NodeConfig, error) {
    data, err := os.ReadFile(path)
    if err != nil {
        return nil, fmt.Errorf("read config: %w", err)
    }

    cfg := &NodeConfig{}
    if err := yaml.Unmarshal(data, cfg); err != nil {
        return nil, fmt.Errorf("parse config: %w", err)
    }

    // Apply defaults
    applyNodeDefaults(cfg)

    // Validate
    if err := validateNodeConfig(cfg); err != nil {
        return nil, fmt.Errorf("validate config: %w", err)
    }

    return cfg, nil
}

func applyNodeDefaults(cfg *NodeConfig) {
    if cfg.Node.Listen == "" {
        cfg.Node.Listen = "0.0.0.0:8080"
    }
    if cfg.Node.DBPath == "" {
        cfg.Node.DBPath = "/var/lib/etlmon/etlmon.db"
    }
    if cfg.Refresh.Disk == 0 {
        cfg.Refresh.Disk = 15 * time.Second
    }
    // ...
}

Validation

func validateNodeConfig(cfg *NodeConfig) error {
    if cfg.Node.NodeName == "" {
        return errors.New("node.node_name is required")
    }

    for i, path := range cfg.Paths {
        if path.Path == "" {
            return fmt.Errorf("paths[%d].path is required", i)
        }
        if _, err := os.Stat(path.Path); err != nil {
            return fmt.Errorf("paths[%d].path does not exist: %s", i, path.Path)
        }
    }

    return nil
}