[Notifications] Support webhook notifications (#6962)

Add webhook notification support

weed/notification/webhook/http.go

@@ -0,0 +1,57 @@
+package webhook
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	util_http "github.com/seaweedfs/seaweedfs/weed/util/http"
+	"google.golang.org/protobuf/proto"
+)
+
+type httpClient struct {
+	endpoint string
+	token    string
+}
+
+func newHTTPClient(cfg *config) (*httpClient, error) {
+	return &httpClient{
+		endpoint: cfg.endpoint,
+		token:    cfg.authBearerToken,
+	}, nil
+}
+
+func (h *httpClient) sendMessage(key string, message proto.Message) error {
+	payload := map[string]interface{}{
+		"key":     key,
+		"message": message,
+	}
+
+	jsonData, err := json.Marshal(payload)
+	if err != nil {
+		return fmt.Errorf("failed to marshal message: %v", err)
+	}
+
+	req, err := http.NewRequest(http.MethodPost, h.endpoint, bytes.NewBuffer(jsonData))
+	if err != nil {
+		return fmt.Errorf("failed to create request: %v", err)
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	if h.token != "" {
+		req.Header.Set("Authorization", "Bearer "+h.token)
+	}
+
+	resp, err := util_http.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to send request: %v", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode < 200 || resp.StatusCode >= 300 {
+		return fmt.Errorf("webhook returned status code: %d", resp.StatusCode)
+	}
+
+	return nil
+}