[Notifications] Support webhook notifications (#6962)

Add webhook notification support

weed/notification/webhook/webhook_queue.go

@@ -0,0 +1,71 @@
+package webhook
+
+import (
+	"fmt"
+	"net/url"
+
+	"github.com/seaweedfs/seaweedfs/weed/notification"
+	"github.com/seaweedfs/seaweedfs/weed/util"
+	"google.golang.org/protobuf/proto"
+)
+
+// client defines the interface for transport client
+// could be extended to support gRPC
+type client interface {
+	sendMessage(key string, message proto.Message) error
+}
+
+func init() {
+	notification.MessageQueues = append(notification.MessageQueues, &WebhookQueue{})
+}
+
+type WebhookQueue struct {
+	client client
+}
+
+type config struct {
+	endpoint        string
+	authBearerToken string
+}
+
+func (c *config) validate() error {
+	_, err := url.Parse(c.endpoint)
+	if err != nil {
+		return fmt.Errorf("invalid webhook endpoint %w", err)
+	}
+
+	return nil
+}
+
+func (w *WebhookQueue) GetName() string {
+	return "webhook"
+}
+
+func (w *WebhookQueue) Initialize(configuration util.Configuration, prefix string) error {
+	c := &config{
+		endpoint:        configuration.GetString(prefix + "endpoint"),
+		authBearerToken: configuration.GetString(prefix + "bearer_token"),
+	}
+
+	if err := c.validate(); err != nil {
+		return err
+	}
+
+	return w.initialize(c)
+}
+
+func (w *WebhookQueue) initialize(cfg *config) error {
+	client, err := newHTTPClient(cfg)
+	if err != nil {
+		return fmt.Errorf("failed to create webhook client: %v", err)
+	}
+	w.client = client
+	return nil
+}
+
+func (w *WebhookQueue) SendMessage(key string, message proto.Message) error {
+	if w.client == nil {
+		return fmt.Errorf("webhook client not initialized")
+	}
+	return w.client.sendMessage(key, message)
+}