feat: add cloudflare auto ttl

.env.example

@@ -30,6 +30,12 @@ PUBLIC_IPV6=
 # TTL (in seconds) for all generated DNS records.
 RECORD_TTL=300
 
+# Enable Cloudflare automatic TTL handling in OctoDNS-generated records:
+# octodns.cloudflare.auto-ttl: true
+# true  - include provider-specific auto-ttl metadata
+# false - do not include provider-specific metadata
+CF_AUTO_TTL=true
+
 # ── DNS Git repository ────────────────────────────────────────────────────────
 
 # Absolute path to the pre-cloned DNS OctoDNS repository on the local filesystem.

config.go

@@ -29,6 +29,7 @@ type Config struct {
 	DebounceDelay     time.Duration
 
 	RecordTTL      int
+	CloudflareAutoTTL bool
 	ExcludeRouters map[string]struct{}
 }
 
@@ -83,6 +84,12 @@ func LoadConfig() (*Config, error) {
 		return nil, fmt.Errorf("RECORD_TTL: invalid integer %q: %w", ttlStr, err)
 	}
 
+	autoTTLStr := envOrDefault("CF_AUTO_TTL", "true")
+	cfg.CloudflareAutoTTL, err = strconv.ParseBool(autoTTLStr)
+	if err != nil {
+		return nil, fmt.Errorf("CF_AUTO_TTL: invalid boolean %q: %w", autoTTLStr, err)
+	}
+
 	cfg.ExcludeRouters = make(map[string]struct{})
 	if v := os.Getenv("EXCLUDE_ROUTERS"); v != "" {
 		for _, r := range strings.Split(v, ",") {

dns.go

@@ -74,6 +74,13 @@ func buildRecord(cfg *Config) interface{} {
 		"type":   "A",
 		"values": []string{cfg.PublicIP},
 	}
+	if cfg.CloudflareAutoTTL {
+		aRec["octodns"] = map[string]interface{}{
+			"cloudflare": map[string]interface{}{
+				"auto-ttl": true,
+			},
+		}
+	}
 	if cfg.PublicIPv6 == "" {
 		return aRec
 	}
@@ -82,6 +89,13 @@ func buildRecord(cfg *Config) interface{} {
 		"type":   "AAAA",
 		"values": []string{cfg.PublicIPv6},
 	}
+	if cfg.CloudflareAutoTTL {
+		aaaaRec["octodns"] = map[string]interface{}{
+			"cloudflare": map[string]interface{}{
+				"auto-ttl": true,
+			},
+		}
+	}
 	return []interface{}{aRec, aaaaRec}
 }