primeiro commit

internal/config/config.go

@@ -0,0 +1,131 @@
+// Package config loads and validates statuspanel YAML configuration.
+package config
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+	"time"
+
+	"gopkg.in/yaml.v3"
+)
+
+const (
+	// DefaultPath is the default configuration path used by statuspanel.
+	DefaultPath = "/etc/statuspanel.yaml"
+)
+
+// Duration wraps time.Duration with YAML string unmarshalling.
+type Duration struct {
+	time.Duration
+}
+
+// UnmarshalYAML decodes duration strings such as "2s" or "500ms".
+func (d *Duration) UnmarshalYAML(value *yaml.Node) error {
+	if value.Kind != yaml.ScalarNode {
+		return fmt.Errorf("duration must be a scalar")
+	}
+	parsed, err := time.ParseDuration(value.Value)
+	if err != nil {
+		return fmt.Errorf("parsing duration %q: %w", value.Value, err)
+	}
+	d.Duration = parsed
+	return nil
+}
+
+// Config describes statuspanel runtime configuration.
+type Config struct {
+	Interface string       `yaml:"interface"`
+	Gateway   string       `yaml:"gateway"`
+	Refresh   Duration     `yaml:"refresh"`
+	DNS       DNSConfig    `yaml:"dns"`
+	Ping      PingConfig   `yaml:"ping"`
+	Targets   []PingTarget `yaml:"targets"`
+}
+
+// DNSConfig describes the DNS probe.
+type DNSConfig struct {
+	Server  string   `yaml:"server"`
+	Domain  string   `yaml:"domain"`
+	Timeout Duration `yaml:"timeout"`
+}
+
+// PingConfig describes ICMP ping behavior.
+type PingConfig struct {
+	Timeout Duration `yaml:"timeout"`
+}
+
+// PingTarget describes a host displayed in the reachability table.
+type PingTarget struct {
+	Name    string `yaml:"name"`
+	Address string `yaml:"address"`
+}
+
+// Default returns a configuration with safe runtime defaults.
+func Default() Config {
+	return Config{
+		Refresh: Duration{Duration: 2 * time.Second},
+		DNS: DNSConfig{
+			Timeout: Duration{Duration: time.Second},
+		},
+		Ping: PingConfig{
+			Timeout: Duration{Duration: time.Second},
+		},
+	}
+}
+
+// Load reads and validates a YAML configuration file.
+func Load(ctx context.Context, path string) (Config, error) {
+	if path == "" {
+		path = DefaultPath
+	}
+	if err := ctx.Err(); err != nil {
+		return Config{}, fmt.Errorf("checking context before loading config: %w", err)
+	}
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return Config{}, fmt.Errorf("reading config %s: %w", path, err)
+	}
+	if err := ctx.Err(); err != nil {
+		return Config{}, fmt.Errorf("checking context after loading config: %w", err)
+	}
+
+	cfg := Default()
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return Config{}, fmt.Errorf("parsing config %s: %w", path, err)
+	}
+	if err := cfg.Validate(); err != nil {
+		return Config{}, fmt.Errorf("validating config %s: %w", path, err)
+	}
+	return cfg, nil
+}
+
+// Validate checks whether the configuration can drive all probes.
+func (c Config) Validate() error {
+	var errs []error
+	if c.Interface == "" {
+		errs = append(errs, errors.New("interface is required"))
+	}
+	if c.Refresh.Duration <= 0 {
+		errs = append(errs, errors.New("refresh must be greater than zero"))
+	}
+	if c.DNS.Server == "" {
+		errs = append(errs, errors.New("dns.server is required"))
+	}
+	if c.DNS.Domain == "" {
+		errs = append(errs, errors.New("dns.domain is required"))
+	}
+	if c.DNS.Timeout.Duration <= 0 {
+		errs = append(errs, errors.New("dns.timeout must be greater than zero"))
+	}
+	if c.Ping.Timeout.Duration <= 0 {
+		errs = append(errs, errors.New("ping.timeout must be greater than zero"))
+	}
+	for i, target := range c.Targets {
+		if target.Address == "" {
+			errs = append(errs, fmt.Errorf("targets[%d].address is required", i))
+		}
+	}
+	return errors.Join(errs...)
+}