feat(M6): token-ring incremental log sync — append-only op log, delta rides token round-2, nodes converge on identical history (e2e verified join events)

internal/cluster/token_transport.go

@@ -0,0 +1,85 @@
+// Token transport: moves the Token between nodes over HTTP POST
+// /api/manager/cluster/token (Basic Auth, same creds). Also used as the
+// heartbeat ping (nil token) between a predecessor and the leader.
+package cluster
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// TokenTransport delivers tokens to a peer's token endpoint.
+type TokenTransport struct {
+	User string
+	Pass string
+	// BaseURL: http://host:port (scheme+authority) used to reach peers.
+	BaseURL string
+}
+
+// SendTo returns a send func bound to this transport: it POSTs the token to
+// next (a node ID) using that node's recorded address from the ring state.
+// If tk is nil it is a heartbeat ping (no body). Returns error on failure.
+func (t *TokenTransport) SendTo(getAddr func(nodeID string) string) func(ctx context.Context, next string, tk *Token) error {
+	return func(ctx context.Context, next string, tk *Token) error {
+		addr := getAddr(next)
+		if addr == "" {
+			// fall back to the treated-as-address peer id
+			addr = next
+		}
+		url := fmt.Sprintf("http://%s/api/manager/cluster/token", addr)
+		var body []byte
+		var err error
+		if tk != nil {
+			body, err = json.Marshal(tk)
+			if err != nil {
+				return err
+			}
+		}
+		req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+		if err != nil {
+			return err
+		}
+		req.Header.Set("Content-Type", "application/json")
+		if t.User != "" || t.Pass != "" {
+			req.SetBasicAuth(t.User, t.Pass)
+		}
+		cli := &http.Client{Timeout: 5 * time.Second}
+		resp, err := cli.Do(req)
+		if err != nil {
+			return err
+		}
+		defer resp.Body.Close()
+		if resp.StatusCode >= 400 {
+			return fmt.Errorf("token POST %s -> HTTP %d", url, resp.StatusCode)
+		}
+		return nil
+	}
+}
+
+// HeartbeatPing is a lightweight alive check WITHOUT body (nil token); it is
+// what the predecessor sends the leader. Response 2xx means alive.
+func (t *TokenTransport) HeartbeatPing(ctx context.Context, addr string) error {
+	url := fmt.Sprintf("http://%s/api/manager/cluster/token", addr)
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
+	if err != nil {
+		return err
+	}
+	req.Header.Set("Content-Type", "application/json")
+	if t.User != "" || t.Pass != "" {
+		req.SetBasicAuth(t.User, t.Pass)
+	}
+	cli := &http.Client{Timeout: 1500 * time.Millisecond}
+	resp, err := cli.Do(req)
+	if err != nil {
+		return err
+	}
+	_ = resp.Body.Close()
+	if resp.StatusCode >= 400 {
+		return fmt.Errorf("heartbeat HTTP %d", resp.StatusCode)
+	}
+	return nil
+}