cloudflared-mirror/connection/manager.go

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package connection
import (
"context"
"crypto/tls"
"fmt"
"sync"
"time"
"github.com/google/uuid"
"github.com/pkg/errors"
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"github.com/prometheus/client_golang/prometheus"
"github.com/sirupsen/logrus"
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"github.com/cloudflare/cloudflared/cmd/cloudflared/buildinfo"
"github.com/cloudflare/cloudflared/h2mux"
"github.com/cloudflare/cloudflared/streamhandler"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
)
const (
quickStartLink = "https://developers.cloudflare.com/argo-tunnel/quickstart/"
faqLink = "https://developers.cloudflare.com/argo-tunnel/faq/"
defaultRetryAfter = time.Second * 5
packageNamespace = "connection"
edgeManagerSubsystem = "edgemanager"
)
// EdgeManager manages connections with the edge
type EdgeManager struct {
// streamHandler handles stream opened by the edge
streamHandler *streamhandler.StreamHandler
// TLSConfig is the TLS configuration to connect with edge
tlsConfig *tls.Config
// cloudflaredConfig is the cloudflared configuration that is determined when the process first starts
cloudflaredConfig *CloudflaredConfig
// serviceDiscoverer returns the next edge addr to connect to
serviceDiscoverer EdgeServiceDiscoverer
// state is attributes of ConnectionManager that can change during runtime.
state *edgeManagerState
logger *logrus.Entry
metrics *metrics
}
type metrics struct {
// activeStreams is a gauge shared by all muxers of this process to expose the total number of active streams
activeStreams prometheus.Gauge
}
func newMetrics(namespace, subsystem string) *metrics {
return &metrics{
activeStreams: h2mux.NewActiveStreamsMetrics(namespace, subsystem),
}
}
// EdgeManagerConfigurable is the configurable attributes of a EdgeConnectionManager
type EdgeManagerConfigurable struct {
TunnelHostnames []h2mux.TunnelHostname
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*tunnelpogs.EdgeConnectionConfig
}
type CloudflaredConfig struct {
CloudflaredID uuid.UUID
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Tags []tunnelpogs.Tag
BuildInfo *buildinfo.BuildInfo
IntentLabel string
}
func NewEdgeManager(
streamHandler *streamhandler.StreamHandler,
edgeConnMgrConfigurable *EdgeManagerConfigurable,
userCredential []byte,
tlsConfig *tls.Config,
serviceDiscoverer EdgeServiceDiscoverer,
cloudflaredConfig *CloudflaredConfig,
logger *logrus.Logger,
) *EdgeManager {
return &EdgeManager{
streamHandler: streamHandler,
tlsConfig: tlsConfig,
cloudflaredConfig: cloudflaredConfig,
serviceDiscoverer: serviceDiscoverer,
state: newEdgeConnectionManagerState(edgeConnMgrConfigurable, userCredential),
logger: logger.WithField("subsystem", "connectionManager"),
metrics: newMetrics(packageNamespace, edgeManagerSubsystem),
}
}
func (em *EdgeManager) Run(ctx context.Context) error {
defer em.shutdown()
resolveEdgeIPTicker := time.Tick(resolveEdgeAddrTTL)
for {
select {
case <-ctx.Done():
return errors.Wrap(ctx.Err(), "EdgeConnectionManager terminated")
case <-resolveEdgeIPTicker:
if err := em.serviceDiscoverer.Refresh(); err != nil {
em.logger.WithError(err).Warn("Cannot refresh Cloudflare edge addresses")
}
default:
time.Sleep(1 * time.Second)
}
// Create/delete connection one at a time, so we don't need to adjust for connections that are being created/deleted
// in shouldCreateConnection or shouldReduceConnection calculation
if em.state.shouldCreateConnection(em.serviceDiscoverer.AvailableAddrs()) {
if connErr := em.newConnection(ctx); connErr != nil {
if !connErr.ShouldRetry {
em.logger.WithError(connErr).Error(em.noRetryMessage())
return connErr
}
em.logger.WithError(connErr).Error("cannot create new connection")
}
} else if em.state.shouldReduceConnection() {
if err := em.closeConnection(ctx); err != nil {
em.logger.WithError(err).Error("cannot close connection")
}
}
}
}
func (em *EdgeManager) UpdateConfigurable(newConfigurable *EdgeManagerConfigurable) {
em.logger.Infof("New edge connection manager configuration %+v", newConfigurable)
em.state.updateConfigurable(newConfigurable)
}
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func (em *EdgeManager) newConnection(ctx context.Context) *tunnelpogs.ConnectError {
edgeTCPAddr, err := em.serviceDiscoverer.Addr()
if err != nil {
return retryConnection(fmt.Sprintf("edge address discovery error: %v", err))
}
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configurable := em.state.getConfigurable()
edgeConn, err := DialEdge(ctx, configurable.Timeout, em.tlsConfig, edgeTCPAddr)
if err != nil {
return retryConnection(fmt.Sprintf("dial edge error: %v", err))
}
// Establish a muxed connection with the edge
// Client mux handshake with agent server
muxer, err := h2mux.Handshake(edgeConn, edgeConn, h2mux.MuxerConfig{
Timeout: configurable.Timeout,
Handler: em.streamHandler,
IsClient: true,
HeartbeatInterval: configurable.HeartbeatInterval,
MaxHeartbeats: configurable.MaxFailedHeartbeats,
Logger: em.logger.WithField("subsystem", "muxer"),
}, em.metrics.activeStreams)
if err != nil {
retryConnection(fmt.Sprintf("couldn't perform handshake with edge: %v", err))
}
h2muxConn, err := newConnection(muxer, edgeTCPAddr)
if err != nil {
return retryConnection(fmt.Sprintf("couldn't create h2mux connection: %v", err))
}
go em.serveConn(ctx, h2muxConn)
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connResult, err := h2muxConn.Connect(ctx, &tunnelpogs.ConnectParameters{
CloudflaredID: em.cloudflaredConfig.CloudflaredID,
CloudflaredVersion: em.cloudflaredConfig.BuildInfo.CloudflaredVersion,
NumPreviousAttempts: 0,
OriginCert: em.state.getUserCredential(),
IntentLabel: em.cloudflaredConfig.IntentLabel,
Tags: em.cloudflaredConfig.Tags,
}, em.logger)
if err != nil {
h2muxConn.Shutdown()
return retryConnection(fmt.Sprintf("couldn't connect to edge: %v", err))
}
if connErr := connResult.ConnectError(); connErr != nil {
return connErr
}
em.state.newConnection(h2muxConn)
em.logger.Infof("connected to %s", connResult.ConnectedTo())
if connResult.ClientConfig() != nil {
em.streamHandler.UseConfiguration(ctx, connResult.ClientConfig())
}
return nil
}
func (em *EdgeManager) closeConnection(ctx context.Context) error {
conn := em.state.getFirstConnection()
if conn == nil {
return fmt.Errorf("no connection to close")
}
conn.Shutdown()
// teardown will be handled by EdgeManager.serveConn in another goroutine
return nil
}
func (em *EdgeManager) serveConn(ctx context.Context, conn *Connection) {
err := conn.Serve(ctx)
em.logger.WithError(err).Warn("Connection closed")
em.state.closeConnection(conn)
em.serviceDiscoverer.ReplaceAddr(conn.addr)
}
func (em *EdgeManager) noRetryMessage() string {
messageTemplate := "cloudflared could not register an Argo Tunnel on your account. Please confirm the following before trying again:" +
"1. You have Argo Smart Routing enabled in your account, See Enable Argo section of %s." +
"2. Your credential at %s is still valid. See %s."
return fmt.Sprintf(messageTemplate, quickStartLink, em.state.getConfigurable().UserCredentialPath, faqLink)
}
func (em *EdgeManager) shutdown() {
em.state.shutdown()
}
type edgeManagerState struct {
sync.RWMutex
configurable *EdgeManagerConfigurable
userCredential []byte
conns map[uuid.UUID]*Connection
}
func newEdgeConnectionManagerState(configurable *EdgeManagerConfigurable, userCredential []byte) *edgeManagerState {
return &edgeManagerState{
configurable: configurable,
userCredential: userCredential,
conns: make(map[uuid.UUID]*Connection),
}
}
func (ems *edgeManagerState) shouldCreateConnection(availableEdgeAddrs int) bool {
ems.RLock()
defer ems.RUnlock()
expectedHAConns := int(ems.configurable.NumHAConnections)
if availableEdgeAddrs < expectedHAConns {
expectedHAConns = availableEdgeAddrs
}
return len(ems.conns) < expectedHAConns
}
func (ems *edgeManagerState) shouldReduceConnection() bool {
ems.RLock()
defer ems.RUnlock()
return uint8(len(ems.conns)) > ems.configurable.NumHAConnections
}
func (ems *edgeManagerState) newConnection(conn *Connection) {
ems.Lock()
defer ems.Unlock()
ems.conns[conn.id] = conn
}
func (ems *edgeManagerState) closeConnection(conn *Connection) {
ems.Lock()
defer ems.Unlock()
delete(ems.conns, conn.id)
}
func (ems *edgeManagerState) getFirstConnection() *Connection {
ems.RLock()
defer ems.RUnlock()
for _, conn := range ems.conns {
return conn
}
return nil
}
func (ems *edgeManagerState) shutdown() {
ems.Lock()
defer ems.Unlock()
for _, conn := range ems.conns {
conn.Shutdown()
}
}
func (ems *edgeManagerState) getConfigurable() *EdgeManagerConfigurable {
ems.Lock()
defer ems.Unlock()
return ems.configurable
}
func (ems *edgeManagerState) updateConfigurable(newConfigurable *EdgeManagerConfigurable) {
ems.Lock()
defer ems.Unlock()
ems.configurable = newConfigurable
}
func (ems *edgeManagerState) getUserCredential() []byte {
ems.RLock()
defer ems.RUnlock()
return ems.userCredential
}
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func retryConnection(cause string) *tunnelpogs.ConnectError {
return &tunnelpogs.ConnectError{
Cause: cause,
RetryAfter: defaultRetryAfter,
ShouldRetry: true,
}
}