cloudflare api

config.go

@@ -16,8 +16,9 @@ type config struct {
 }
 
 type domain struct {
-	Type string `json:"type"`
-	Name string `json:"name"`
+	Type     string `json:"type"`
+	Name     string `json:"name"`
+	ZoneName string `json:"zoneName,omitempty"`
 	// TODO: lograr que esto sea un coso de propiedades arbitrario
 	Key string `json:"key"`
 }
@@ -68,6 +69,16 @@ func LoadConfig(path string) (state State, err error) {
 				Name:       d.Name,
 				NameServer: &nameservers.HeNet{HTTPClient: &state.HTTPClient, Password: d.Key},
 			})
+		case "cloudflare v4 api":
+			if len(d.ZoneName) == 0 {
+				err = errors.New("cloudflare v4 api: missing zoneName property")
+				return
+			}
+			state.Domains = append(state.Domains, Domain{
+				Name: d.Name,
+				NameServer: &nameservers.CloudflareV4{HTTPClient: &state.HTTPClient, Key: d.Key,
+					ZoneName: d.ZoneName},
+			})
 		default:
 			err = errors.New("I don't know the service type " + d.Type)
 			return

nameservers/cloudflare.go

@@ -0,0 +1,163 @@
+package nameservers
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+)
+
+type CloudflareV4 struct {
+	HTTPClient *http.Client
+	Key        string
+	ZoneName   string
+}
+
+func (c *CloudflareV4) SetRecord(ctx context.Context, domain string, overrideIp string) (string, error) {
+	zoneId, err := c.apiGetZoneId(ctx)
+	if err != nil {
+		return "", err
+	}
+	recordId, err := c.apiGetDnsRecordId(ctx, zoneId, domain)
+	if err != nil {
+		return "", err
+	}
+
+	content := overrideIp
+	if len(content) == 0 {
+		ip, err := c.getIp(ctx)
+		if err != nil {
+			return "", err
+		}
+		content = ip
+	}
+
+	result, err := c.apiUpdateDnsRecord(ctx, zoneId, domain, recordId, content)
+	return result, err
+}
+
+func (c *CloudflareV4) apiReq(ctx context.Context, path string, method string, reqBody io.Reader) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, method, "https://api.cloudflare.com"+path, reqBody)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Add("Authorization", "Bearer "+c.Key)
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, err
+	}
+	return body, nil
+}
+func (c *CloudflareV4) apiGet(ctx context.Context, path string) ([]byte, error) {
+	return c.apiReq(ctx, path, "GET", nil)
+}
+
+func (c *CloudflareV4) getIp(ctx context.Context) (string, error) {
+	// icanhazip.com es manejado por Cloudflare https://blog.apnic.net/2021/06/17/how-a-small-free-ip-tool-survived/
+	req, err := http.NewRequestWithContext(ctx, "GET", "https://ipv4.icanhazip.com/", nil)
+	if err != nil {
+		return "", err
+	}
+	resp, err := c.HTTPClient.Do(req)
+	if err != nil {
+		return "", err
+	}
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+	return string(body), nil
+}
+
+type apiZoneSearchResponse struct {
+	Result []struct {
+		Id string `json:"id"`
+	} `json:"result"`
+}
+
+func (c *CloudflareV4) apiGetZoneId(ctx context.Context) (string, error) {
+	str, err := c.apiGet(ctx, "/client/v4/zones?name="+c.ZoneName)
+	if err != nil {
+		return "", err
+	}
+	var resp apiZoneSearchResponse
+	err = json.Unmarshal(str, &resp)
+	if err != nil {
+		return "", err
+	}
+	if len(resp.Result) != 1 {
+		return "", errors.New("expected result to be len()=1 but len is " + fmt.Sprintf("%d", len(resp.Result)))
+	}
+	return resp.Result[0].Id, nil
+}
+
+type apiDnsRecordSearchResponse struct {
+	Result []struct {
+		Id string `json:"id"`
+	} `json:"result"`
+}
+
+func (c *CloudflareV4) apiGetDnsRecordId(ctx context.Context, zoneId, domain string) (string, error) {
+	str, err := c.apiGet(ctx, fmt.Sprintf("/client/v4/zones/%s/dns_records?type=A&name=%s", zoneId, domain))
+	if err != nil {
+		return "", err
+	}
+	var resp apiDnsRecordSearchResponse
+	err = json.Unmarshal(str, &resp)
+	if err != nil {
+		return "", err
+	}
+	if len(resp.Result) != 1 {
+		return "", errors.New("expected result to be len()=1 but len is " + fmt.Sprintf("%d", len(resp.Result)))
+	}
+	return resp.Result[0].Id, nil
+}
+
+// https://developers.cloudflare.com/api/operations/dns-records-for-a-zone-patch-dns-record
+type apiUpdateDnsRecordRequest struct {
+	Content string `json:"content"`
+	Name    string `json:"name"`
+	Type    string `json:"type"`
+}
+type apiUpdateDnsRecordResponse struct {
+	Result []struct {
+		Id      string `json:"id"`
+		Content string `json:"content"`
+	} `json:"result"`
+}
+
+func (c *CloudflareV4) apiUpdateDnsRecord(ctx context.Context, zoneId, zoneName, recordId, content string) (string, error) {
+	body, err := json.Marshal(apiUpdateDnsRecordRequest{
+		Content: content,
+		Name:    zoneName,
+		Type:    "A",
+	})
+	if err != nil {
+		return "", err
+	}
+
+	str, err := c.apiReq(ctx,
+		fmt.Sprintf("/client/v4/zones/%s/dns_records/%s", zoneId, recordId),
+		"PATCH", bytes.NewReader(body))
+	if err != nil {
+		return "", err
+	}
+	log.Printf("debug: [cloudflareV4(%s)] Response: %s", zoneName, string(body))
+	var resp apiUpdateDnsRecordResponse
+	err = json.Unmarshal(str, &resp)
+	if err != nil {
+		return "", err
+	}
+	if len(resp.Result) != 1 {
+		return "", errors.New("expected result to be len()=1 but len is " + fmt.Sprintf("%d", len(resp.Result)))
+	}
+	return resp.Result[0].Content, nil
+}

readme.md

@@ -21,6 +21,12 @@ Create a config file:
       "type": "he.net ddns",
       "name": "pruebas.bat.ar",
       "key": "INSERT_KEY"
+    },
+    {
+      "type": "cloudflare v4 api",
+      "name": "*.nulo.in",
+      "zoneName": "nulo.in",
+      "key": "INSERT_KEY" // https://dash.cloudflare.com/profile/api-tokens
     }
   ]
 }