cloudflared-mirror/connection/observer.go

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package connection
import (
"fmt"
"net/url"
"strings"
tunnelpogs "github.com/cloudflare/cloudflared/tunnelrpc/pogs"
"github.com/rs/zerolog"
)
const (
LogFieldLocation = "location"
observerChannelBufferSize = 16
)
type Observer struct {
log *zerolog.Logger
logTransport *zerolog.Logger
metrics *tunnelMetrics
tunnelEventChan chan Event
uiEnabled bool
addSinkChan chan EventSink
}
type EventSink interface {
OnTunnelEvent(event Event)
}
func NewObserver(log, logTransport *zerolog.Logger, uiEnabled bool) *Observer {
o := &Observer{
log: log,
logTransport: logTransport,
metrics: newTunnelMetrics(),
uiEnabled: uiEnabled,
tunnelEventChan: make(chan Event, observerChannelBufferSize),
addSinkChan: make(chan EventSink, observerChannelBufferSize),
}
go o.dispatchEvents()
return o
}
func (o *Observer) RegisterSink(sink EventSink) {
o.addSinkChan <- sink
}
func (o *Observer) logServerInfo(connIndex uint8, location, msg string) {
o.sendEvent(Event{Index: connIndex, EventType: Connected, Location: location})
o.log.Info().
Uint8(LogFieldConnIndex, connIndex).
Str(LogFieldLocation, location).
Msg(msg)
o.metrics.registerServerLocation(uint8ToString(connIndex), location)
}
func (o *Observer) logTrialHostname(registration *tunnelpogs.TunnelRegistration) error {
// Print out the user's trial zone URL in a nice box (if they requested and got one and UI flag is not set)
if !o.uiEnabled {
if registrationURL, err := url.Parse(registration.Url); err == nil {
for _, line := range asciiBox(trialZoneMsg(registrationURL.String()), 2) {
o.log.Info().Msg(line)
}
} else {
o.log.Error().Msg("Failed to connect tunnel, please try again.")
return fmt.Errorf("empty URL in response from Cloudflare edge")
}
}
return nil
}
// Print out the given lines in a nice ASCII box.
func asciiBox(lines []string, padding int) (box []string) {
maxLen := maxLen(lines)
spacer := strings.Repeat(" ", padding)
border := "+" + strings.Repeat("-", maxLen+(padding*2)) + "+"
box = append(box, border)
for _, line := range lines {
box = append(box, "|"+spacer+line+strings.Repeat(" ", maxLen-len(line))+spacer+"|")
}
box = append(box, border)
return
}
func maxLen(lines []string) int {
max := 0
for _, line := range lines {
if len(line) > max {
max = len(line)
}
}
return max
}
func trialZoneMsg(url string) []string {
return []string{
"Your free tunnel has started! Visit it:",
" " + url,
}
}
func (o *Observer) sendRegisteringEvent(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: RegisteringTunnel})
}
func (o *Observer) sendConnectedEvent(connIndex uint8, location string) {
o.sendEvent(Event{Index: connIndex, EventType: Connected, Location: location})
}
func (o *Observer) sendURL(url string) {
o.sendEvent(Event{EventType: SetURL, URL: url})
}
func (o *Observer) SendReconnect(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: Reconnecting})
}
func (o *Observer) SendDisconnect(connIndex uint8) {
o.sendEvent(Event{Index: connIndex, EventType: Disconnected})
}
func (o *Observer) sendEvent(e Event) {
select {
case o.tunnelEventChan <- e:
break
default:
o.log.Warn().Msg("observer channel buffer is full")
}
}
func (o *Observer) dispatchEvents() {
var sinks []EventSink
for {
select {
case sink := <-o.addSinkChan:
sinks = append(sinks, sink)
case evt := <-o.tunnelEventChan:
for _, sink := range sinks {
sink.OnTunnelEvent(evt)
}
}
}
}
type EventSinkFunc func(event Event)
func (f EventSinkFunc) OnTunnelEvent(event Event) {
f(event)
}