Add Cloudflare API provider

Signed-off-by: Mel <mel@rnrd.eu>

2 files changed, 99 insertions, 2 deletions

diff --git a/provider/cloudflare.go b/provider/cloudflare.go
new file mode 100644
index 0000000..8ca58bb
--- /dev/null
+++ b/provider/cloudflare.go
@@ -0,0 +1,94 @@
+package provider
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"log/slog"
+	"net/netip"
+	"net/url"
+)
+
+type cloudflare struct {
+	log *slog.Logger
+	key string
+}
+
+var _ Provider = (*cloudflare)(nil)
+
+func newCloudflare(log *slog.Logger, cfg Config) (*cloudflare, error) {
+	key, err := cfg.key()
+	if err != nil {
+		return nil, fmt.Errorf("failed instantiating cloudflare provider: %w", err)
+	}
+	return &cloudflare{key: key, log: log}, nil
+}
+
+const cfAPI = "https://api.cloudflare.com/client/v4"
+
+func (c *cloudflare) headers() map[string]string {
+	return map[string]string{"Authorization": "Bearer " + c.key}
+}
+
+func (c *cloudflare) Ensure(zone, name string, rtype RecordType, addr netip.Addr) (string, bool, error) {
+	c.log.Info("updating record via cloudflare api")
+
+	var zones struct {
+		Result []struct {
+			ID string `json:"id"`
+		} `json:"result"`
+	}
+	raw, err := request("GET", cfAPI+"/zones?name="+url.QueryEscape(zone),
+		c.headers(), nil)
+	if err != nil {
+		return "", false, err
+	}
+	if err := json.Unmarshal(raw, &zones); err != nil {
+		return "", false, err
+	}
+	if len(zones.Result) == 0 {
+		return "", false, fmt.Errorf("zone %s not found in cloudflare", zone)
+	}
+	zoneID := zones.Result[0].ID
+
+	fqdn := name + "." + zone
+	var records struct {
+		Result []struct {
+			ID      string `json:"id"`
+			Content string `json:"content"`
+		} `json:"result"`
+	}
+	raw, err = request("GET", fmt.Sprintf("%s/zones/%s/dns_records?type=%s&name=%s",
+		cfAPI, zoneID, string(rtype), url.QueryEscape(fqdn)), c.headers(), nil)
+	if err != nil {
+		return "", false, fmt.Errorf("failed to search for record in cloudflare: %w", err)
+	}
+	if err := json.Unmarshal(raw, &records); err != nil {
+		return "", false, fmt.Errorf("received malformed search results from cloudflare: %w", err)
+	}
+
+	body, _ := json.Marshal(map[string]any{
+		"type":    string(rtype),
+		"name":    fqdn,
+		"content": addr.String(),
+		"ttl":     300,
+	})
+
+	if len(records.Result) == 0 {
+		// if nothing found, create
+		c.log.Info("record not found in cloudflare, creating")
+		_, err = request("POST", fmt.Sprintf("%s/zones/%s/dns_records", cfAPI, zoneID),
+			c.headers(), bytes.NewReader(body))
+		return "", true, err
+	}
+
+	rec := records.Result[0]
+	if rec.Content == addr.String() {
+		return rec.Content, false, nil
+	}
+	// if record found, update
+	c.log.Info("record found in cloudflare, updating", slog.Group("cloudflare", slog.String("id", rec.ID), slog.String("content", rec.Content)))
+	_, err = request("PUT", fmt.Sprintf("%s/zones/%s/dns_records/%s", cfAPI, zoneID, rec.ID),
+		c.headers(), bytes.NewReader(body))
+	return rec.Content, true, err
+}
diff --git a/provider/provider.go b/provider/provider.go
index 3f147e5..613d05f 100644
--- a/provider/provider.go
+++ b/provider/provider.go
@@ -15,8 +15,9 @@ import (
 type Kind string
 
 const (
-	KindDummy Kind = "dummy"
-	KindBunny Kind = "bunny"
+	KindDummy      Kind = "dummy"
+	KindBunny      Kind = "bunny"
+	KindCloudflare Kind = "cloudflare"
 )
 
 type RecordType string
@@ -77,6 +78,8 @@ func New(log *slog.Logger, name string, cfg Config) (Provider, error) {
 		return newDummy(log)
 	case KindBunny:
 		return newBunny(log, cfg)
+	case KindCloudflare:
+		return newCloudflare(log, cfg)
 	default:
 		return nil, fmt.Errorf("unknown provider kind %q", cfg.Kind)
 	}