more stuff

pkg/proxy/remotehost.go

@@ -0,0 +1,210 @@
+package proxy
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"log"
+	"net/http"
+	"time"
+
+	messages "git.tornberg.me/go-cart-actor/pkg/messages"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+)
+
+// RemoteHost mirrors the lightweight controller used for remote node
+// interaction.
+type RemoteHost struct {
+	Host          string
+	httpBase      string
+	conn          *grpc.ClientConn
+	transport     *http.Transport
+	client        *http.Client
+	controlClient messages.ControlPlaneClient
+	MissedPings   int
+}
+
+func NewRemoteHost(host string) (*RemoteHost, error) {
+
+	target := fmt.Sprintf("%s:1337", host)
+
+	conn, err := grpc.NewClient(target, grpc.WithTransportCredentials(insecure.NewCredentials()))
+
+	if err != nil {
+		log.Printf("AddRemote: dial %s failed: %v", target, err)
+		return nil, err
+	}
+
+	controlClient := messages.NewControlPlaneClient(conn)
+	for retries := range 3 {
+		ctx, pingCancel := context.WithTimeout(context.Background(), time.Second)
+		_, pingErr := controlClient.Ping(ctx, &messages.Empty{})
+		pingCancel()
+		if pingErr == nil {
+			break
+		}
+		if retries == 2 {
+			log.Printf("AddRemote: ping %s failed after retries: %v", host, pingErr)
+			conn.Close()
+			return nil, pingErr
+		}
+		time.Sleep(200 * time.Millisecond)
+	}
+
+	transport := &http.Transport{
+		MaxIdleConns:        100,
+		MaxIdleConnsPerHost: 100,
+		IdleConnTimeout:     120 * time.Second,
+	}
+	client := &http.Client{Transport: transport, Timeout: 10 * time.Second}
+
+	return &RemoteHost{
+		Host:          host,
+		httpBase:      fmt.Sprintf("http://%s:8080/cart", host),
+		conn:          conn,
+		transport:     transport,
+		client:        client,
+		controlClient: controlClient,
+		MissedPings:   0,
+	}, nil
+}
+
+func (h *RemoteHost) Name() string {
+	return h.Host
+}
+
+func (h *RemoteHost) Close() error {
+	if h.conn != nil {
+		h.conn.Close()
+	}
+	return nil
+}
+
+func (h *RemoteHost) Ping() bool {
+
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	_, err := h.controlClient.Ping(ctx, &messages.Empty{})
+	cancel()
+	if err != nil {
+		h.MissedPings++
+		log.Printf("Ping %s failed (%d)", h.Host, h.MissedPings)
+		return false
+	}
+
+	h.MissedPings = 0
+	return true
+}
+
+func (h *RemoteHost) Negotiate(knownHosts []string) ([]string, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+	defer cancel()
+
+	resp, err := h.controlClient.Negotiate(ctx, &messages.NegotiateRequest{
+		KnownHosts: knownHosts,
+	})
+	if err != nil {
+		h.MissedPings++
+		log.Printf("Negotiate %s failed: %v", h.Host, err)
+		return nil, err
+	}
+	h.MissedPings = 0
+	return resp.Hosts, nil
+}
+
+func (h *RemoteHost) GetActorIds() []uint64 {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+	reply, err := h.controlClient.GetLocalActorIds(ctx, &messages.Empty{})
+	if err != nil {
+		log.Printf("Init remote %s: GetCartIds error: %v", h.Host, err)
+		h.MissedPings++
+		return []uint64{}
+	}
+	return reply.GetIds()
+}
+
+func (h *RemoteHost) AnnounceOwnership(uids []uint64) {
+	_, err := h.controlClient.AnnounceOwnership(context.Background(), &messages.OwnershipAnnounce{
+		Host: h.Host,
+		Ids:  uids,
+	})
+	if err != nil {
+		log.Printf("ownership announce to %s failed: %v", h.Host, err)
+		h.MissedPings++
+		return
+	}
+	h.MissedPings = 0
+}
+
+func (h *RemoteHost) AnnounceExpiry(uids []uint64) {
+	_, err := h.controlClient.AnnounceExpiry(context.Background(), &messages.ExpiryAnnounce{
+		Host: h.Host,
+		Ids:  uids,
+	})
+	if err != nil {
+		log.Printf("expiry announce to %s failed: %v", h.Host, err)
+		h.MissedPings++
+		return
+	}
+	h.MissedPings = 0
+}
+
+func (h *RemoteHost) Proxy(id uint64, w http.ResponseWriter, r *http.Request) (bool, error) {
+	target := fmt.Sprintf("%s%s", h.httpBase, r.URL.RequestURI())
+	var bodyCopy []byte
+	if r.Body != nil && r.Body != http.NoBody {
+		var err error
+		bodyCopy, err = io.ReadAll(r.Body)
+		if err != nil {
+			http.Error(w, "proxy read error", http.StatusBadGateway)
+			return false, err
+		}
+	}
+	if r.Body != nil {
+		r.Body.Close()
+	}
+	var reqBody io.Reader
+	if len(bodyCopy) > 0 {
+		reqBody = bytes.NewReader(bodyCopy)
+	}
+	req, err := http.NewRequestWithContext(r.Context(), r.Method, target, reqBody)
+	if err != nil {
+		http.Error(w, "proxy build error", http.StatusBadGateway)
+		return false, err
+	}
+	r.Body = io.NopCloser(bytes.NewReader(bodyCopy))
+	req.Header.Set("X-Forwarded-Host", r.Host)
+
+	for k, v := range r.Header {
+		for _, vv := range v {
+			req.Header.Add(k, vv)
+		}
+	}
+	res, err := h.client.Do(req)
+	if err != nil {
+		http.Error(w, "proxy request error", http.StatusBadGateway)
+		return false, err
+	}
+	defer res.Body.Close()
+	for k, v := range res.Header {
+		for _, vv := range v {
+			w.Header().Add(k, vv)
+		}
+	}
+	w.Header().Set("X-Cart-Owner-Routed", "true")
+	if res.StatusCode >= 200 && res.StatusCode <= 299 {
+		w.WriteHeader(res.StatusCode)
+		_, copyErr := io.Copy(w, res.Body)
+		if copyErr != nil {
+			return true, copyErr
+		}
+		return true, nil
+	}
+	return false, fmt.Errorf("proxy response status %d", res.StatusCode)
+}
+
+func (r *RemoteHost) IsHealthy() bool {
+	return r.MissedPings < 3
+}