TUN-1626: Create new supervisor to establish connection with origintunneld

connection/supervisor.go

@@ -0,0 +1,145 @@
+package connection
+
+import (
+	"context"
+	"net"
+	"time"
+
+	tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
+	"github.com/google/uuid"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+)
+
+const (
+	// Waiting time before retrying a failed tunnel connection
+	reconnectDuration = time.Second * 10
+	// SRV record resolution TTL
+	resolveTTL = time.Hour
+	// Interval between establishing new connection
+	connectionInterval = time.Second
+)
+
+type CloudflaredConfig struct {
+	ConnectionConfig *ConnectionConfig
+	OriginCert       []byte
+	Tags             []tunnelpogs.Tag
+	EdgeAddrs        []string
+	HAConnections    uint
+	Logger           *logrus.Logger
+}
+
+// Supervisor is a stateful object that manages connections with the edge
+type Supervisor struct {
+	config     *CloudflaredConfig
+	state      *supervisorState
+	connErrors chan error
+}
+
+type supervisorState struct {
+	// IPs to connect to cloudflare's edge network
+	edgeIPs []*net.TCPAddr
+	// index of the next element to use in edgeIPs
+	nextEdgeIPIndex int
+	// last time edgeIPs were refreshed
+	lastResolveTime time.Time
+	// ID of this cloudflared instance
+	cloudflaredID uuid.UUID
+	// connectionPool is a pool of connectionHandlers that can be used to make RPCs
+	connectionPool *connectionPool
+}
+
+func (s *supervisorState) getNextEdgeIP() *net.TCPAddr {
+	ip := s.edgeIPs[s.nextEdgeIPIndex%len(s.edgeIPs)]
+	s.nextEdgeIPIndex++
+	return ip
+}
+
+func NewSupervisor(config *CloudflaredConfig) *Supervisor {
+	return &Supervisor{
+		config: config,
+		state: &supervisorState{
+			connectionPool: &connectionPool{},
+		},
+		connErrors: make(chan error),
+	}
+}
+
+func (s *Supervisor) Run(ctx context.Context) error {
+	logger := s.config.Logger
+	if err := s.initialize(); err != nil {
+		logger.WithError(err).Error("Failed to get edge IPs")
+		return err
+	}
+	defer s.state.connectionPool.close()
+
+	var currentConnectionCount uint
+	expectedConnectionCount := s.config.HAConnections
+	if uint(len(s.state.edgeIPs)) < s.config.HAConnections {
+		logger.Warnf("You requested %d HA connections but I can give you at most %d.", s.config.HAConnections, len(s.state.edgeIPs))
+		expectedConnectionCount = uint(len(s.state.edgeIPs))
+	}
+	for {
+		select {
+		case <-ctx.Done():
+			return nil
+		case connErr := <-s.connErrors:
+			logger.WithError(connErr).Warnf("Connection dropped unexpectedly")
+			currentConnectionCount--
+		default:
+			time.Sleep(5 * time.Second)
+		}
+		if currentConnectionCount < expectedConnectionCount {
+			h, err := newH2MuxHandler(ctx, s.config.ConnectionConfig, s.state.getNextEdgeIP())
+			if err != nil {
+				logger.WithError(err).Error("Failed to create new connection handler")
+				continue
+			}
+			go func() {
+				s.connErrors <- h.serve(ctx)
+			}()
+			connResult, err := s.connect(ctx, s.config, s.state.cloudflaredID, h)
+			if err != nil {
+				logger.WithError(err).Errorf("Failed to connect to cloudflared's edge network")
+				h.shutdown()
+				continue
+			}
+			if connErr := connResult.Err; connErr != nil && !connErr.ShouldRetry {
+				logger.WithError(connErr).Errorf("Server respond with don't retry to connect")
+				h.shutdown()
+				return err
+			}
+			logger.Infof("Connected to %s", connResult.ServerInfo.LocationName)
+			s.state.connectionPool.put(h)
+			currentConnectionCount++
+		}
+	}
+}
+
+func (s *Supervisor) initialize() error {
+	edgeIPs, err := ResolveEdgeIPs(s.config.Logger, s.config.EdgeAddrs)
+	if err != nil {
+		return errors.Wrapf(err, "Failed to resolve cloudflare edge network address")
+	}
+	s.state.edgeIPs = edgeIPs
+	s.state.lastResolveTime = time.Now()
+	cloudflaredID, err := uuid.NewRandom()
+	if err != nil {
+		return errors.Wrap(err, "Failed to generate cloudflared ID")
+	}
+	s.state.cloudflaredID = cloudflaredID
+	return nil
+}
+
+func (s *Supervisor) connect(ctx context.Context,
+	config *CloudflaredConfig,
+	cloudflaredID uuid.UUID,
+	h connectionHandler,
+) (*tunnelpogs.ConnectResult, error) {
+	connectParameters := &tunnelpogs.ConnectParameters{
+		OriginCert:          config.OriginCert,
+		CloudflaredID:       cloudflaredID,
+		NumPreviousAttempts: 0,
+	}
+	return h.connect(ctx, connectParameters)
+}