github.com/mysteriumnetwork/node@v0.0.0-20240516044423-365054f76801/nat/event/sender.go (about)

     1  /*
     2   * Copyright (C) 2019 The "MysteriumNetwork/node" Authors.
     3   *
     4   * This program is free software: you can redistribute it and/or modify
     5   * it under the terms of the GNU General Public License as published by
     6   * the Free Software Foundation, either version 3 of the License, or
     7   * (at your option) any later version.
     8   *
     9   * This program is distributed in the hope that it will be useful,
    10   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    11   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    12   * GNU General Public License for more details.
    13   *
    14   * You should have received a copy of the GNU General Public License
    15   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    16   */
    17  
    18  package event
    19  
    20  import (
    21  	"github.com/mysteriumnetwork/node/eventbus"
    22  	"github.com/rs/zerolog/log"
    23  )
    24  
    25  // Sender allows subscribing to NAT events and sends them to server
    26  type Sender struct {
    27  	metricsSender metricsSender
    28  	ipResolver    ipResolver
    29  	gatewayLoader func() []map[string]string
    30  	lastIp        string
    31  	lastEvent     *Event
    32  }
    33  
    34  type metricsSender interface {
    35  	SendNATMappingSuccessEvent(id, stage string, gateways []map[string]string)
    36  	SendNATMappingFailEvent(id, stage string, gateways []map[string]string, err error)
    37  }
    38  
    39  type ipResolver func() (string, error)
    40  
    41  // NewSender returns a new instance of events sender
    42  func NewSender(metricsSender metricsSender, ipResolver ipResolver, gatewayLoader func() []map[string]string) *Sender {
    43  	return &Sender{
    44  		metricsSender: metricsSender,
    45  		ipResolver:    ipResolver,
    46  		lastIp:        "",
    47  		gatewayLoader: gatewayLoader,
    48  	}
    49  }
    50  
    51  // Subscribe subscribes to relevant events of event bus.
    52  func (es *Sender) Subscribe(bus eventbus.Subscriber) error {
    53  	return bus.Subscribe(AppTopicTraversal, es.consumeNATEvent)
    54  }
    55  
    56  // consumeNATEvent sends received event to server
    57  func (es *Sender) consumeNATEvent(event Event) {
    58  	publicIP, err := es.ipResolver()
    59  	if err != nil {
    60  		log.Warn().Err(err).Msg("Resolving public IP failed")
    61  		return
    62  	}
    63  
    64  	if publicIP == es.lastIp && es.matchesLastEvent(event) {
    65  		return
    66  	}
    67  
    68  	es.sendNATEvent(event)
    69  
    70  	es.lastIp = publicIP
    71  	es.lastEvent = &event
    72  }
    73  
    74  func (es *Sender) sendNATEvent(event Event) {
    75  	if event.Successful {
    76  		es.metricsSender.SendNATMappingSuccessEvent(event.ID, event.Stage, es.gatewayLoader())
    77  	} else {
    78  		es.metricsSender.SendNATMappingFailEvent(event.ID, event.Stage, es.gatewayLoader(), event.Error)
    79  	}
    80  }
    81  
    82  func (es *Sender) matchesLastEvent(event Event) bool {
    83  	if es.lastEvent == nil {
    84  		return false
    85  	}
    86  
    87  	return event.Successful == es.lastEvent.Successful && event.Stage == es.lastEvent.Stage
    88  }