alertmanager-irc-relay/irc.go

264 lines
7.1 KiB
Go
Raw Normal View History

// Copyright 2018 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package main
import (
"context"
"crypto/tls"
"log"
"strconv"
"strings"
"sync"
"time"
irc "github.com/fluffle/goirc/client"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
const (
pingFrequencySecs = 60
connectionTimeoutSecs = 30
nickservWaitSecs = 10
ircConnectMaxBackoffSecs = 300
ircConnectBackoffResetSecs = 1800
)
var (
ircConnectedGauge = promauto.NewGauge(prometheus.GaugeOpts{
Name: "irc_connected",
Help: "Whether the IRC connection is established",
})
ircSentMsgs = promauto.NewCounterVec(prometheus.CounterOpts{
Name: "irc_sent_msgs",
Help: "Number of IRC messages sent"},
[]string{"ircchannel"},
)
ircSendMsgErrors = promauto.NewCounterVec(prometheus.CounterOpts{
Name: "irc_send_msg_errors",
Help: "Errors while sending IRC messages"},
[]string{"ircchannel", "error"},
)
)
func loggerHandler(_ *irc.Conn, line *irc.Line) {
log.Printf("Received: '%s'", line.Raw)
}
func makeGOIRCConfig(config *Config) *irc.Config {
ircConfig := irc.NewConfig(config.IRCNick)
ircConfig.Me.Ident = config.IRCNick
ircConfig.Me.Name = config.IRCRealName
ircConfig.Server = strings.Join(
[]string{config.IRCHost, strconv.Itoa(config.IRCPort)}, ":")
ircConfig.Pass = config.IRCHostPass
ircConfig.SSL = config.IRCUseSSL
ircConfig.SSLConfig = &tls.Config{
ServerName: config.IRCHost,
InsecureSkipVerify: !config.IRCVerifySSL,
}
ircConfig.PingFreq = pingFrequencySecs * time.Second
ircConfig.Timeout = connectionTimeoutSecs * time.Second
ircConfig.NewNick = func(n string) string { return n + "^" }
return ircConfig
}
type IRCNotifier struct {
// Nick stores the nickname specified in the config, because irc.Client
// might change its copy.
Nick string
NickPassword string
Client *irc.Conn
AlertMsgs chan AlertMsg
stopCtx context.Context
stopWg *sync.WaitGroup
// irc.Conn has a Connected() method that can tell us wether the TCP
// connection is up, and thus if we should trigger connect/disconnect.
// We need to track the session establishment also at a higher level to
// understand when the server has accepted us and thus when we can join
// channels, send notices, etc.
sessionUp bool
sessionUpSignal chan bool
sessionDownSignal chan bool
channelReconciler *ChannelReconciler
UsePrivmsg bool
NickservDelayWait time.Duration
BackoffCounter Delayer
}
func NewIRCNotifier(stopCtx context.Context, stopWg *sync.WaitGroup, config *Config, alertMsgs chan AlertMsg, delayerMaker DelayerMaker) (*IRCNotifier, error) {
ircConfig := makeGOIRCConfig(config)
client := irc.Client(ircConfig)
backoffCounter := delayerMaker.NewDelayer(
ircConnectMaxBackoffSecs, ircConnectBackoffResetSecs,
time.Second)
channelReconciler := NewChannelReconciler(config, client, delayerMaker)
notifier := &IRCNotifier{
Nick: config.IRCNick,
NickPassword: config.IRCNickPass,
Client: client,
AlertMsgs: alertMsgs,
stopCtx: stopCtx,
stopWg: stopWg,
sessionUpSignal: make(chan bool),
sessionDownSignal: make(chan bool),
channelReconciler: channelReconciler,
UsePrivmsg: config.UsePrivmsg,
NickservDelayWait: nickservWaitSecs * time.Second,
BackoffCounter: backoffCounter,
}
notifier.registerHandlers()
return notifier, nil
}
func (n *IRCNotifier) registerHandlers() {
n.Client.HandleFunc(irc.CONNECTED,
func(*irc.Conn, *irc.Line) {
log.Printf("Session established")
n.sessionUpSignal <- true
})
n.Client.HandleFunc(irc.DISCONNECTED,
func(*irc.Conn, *irc.Line) {
log.Printf("Disconnected from IRC")
n.sessionDownSignal <- false
})
for _, event := range []string{irc.NOTICE, "433"} {
n.Client.HandleFunc(event, loggerHandler)
}
}
func (n *IRCNotifier) MaybeIdentifyNick() {
if n.NickPassword == "" {
return
}
// Very lazy/optimistic, but this is good enough for my irssi config,
// so it should work here as well.
currentNick := n.Client.Me().Nick
if currentNick != n.Nick {
log.Printf("My nick is '%s', sending GHOST to NickServ to get '%s'",
currentNick, n.Nick)
n.Client.Privmsgf("NickServ", "GHOST %s %s", n.Nick,
n.NickPassword)
time.Sleep(n.NickservDelayWait)
log.Printf("Changing nick to '%s'", n.Nick)
n.Client.Nick(n.Nick)
}
log.Printf("Sending IDENTIFY to NickServ")
n.Client.Privmsgf("NickServ", "IDENTIFY %s", n.NickPassword)
time.Sleep(n.NickservDelayWait)
}
func (n *IRCNotifier) MaybeSendAlertMsg(alertMsg *AlertMsg) {
if !n.sessionUp {
log.Printf("Cannot send alert to %s : IRC not connected",
alertMsg.Channel)
ircSendMsgErrors.WithLabelValues(alertMsg.Channel, "not_connected").Inc()
return
}
n.channelReconciler.JoinChannel(&IRCChannel{Name: alertMsg.Channel})
if n.UsePrivmsg {
n.Client.Privmsg(alertMsg.Channel, alertMsg.Alert)
} else {
n.Client.Notice(alertMsg.Channel, alertMsg.Alert)
}
ircSentMsgs.WithLabelValues(alertMsg.Channel).Inc()
}
func (n *IRCNotifier) ShutdownPhase() {
if n.Client.Connected() {
log.Printf("IRC client connected, quitting")
n.Client.Quit("see ya")
if n.sessionUp {
log.Printf("Session is up, wait for IRC disconnect to complete")
select {
case <-n.sessionDownSignal:
case <-time.After(n.Client.Config().Timeout):
log.Printf("Timeout while waiting for IRC disconnect to complete, stopping anyway")
}
}
}
}
func (n *IRCNotifier) ConnectedPhase() {
select {
case alertMsg := <-n.AlertMsgs:
n.MaybeSendAlertMsg(&alertMsg)
case <-n.sessionDownSignal:
n.sessionUp = false
n.channelReconciler.CleanupChannels()
n.Client.Quit("see ya")
ircConnectedGauge.Set(0)
case <-n.stopCtx.Done():
log.Printf("IRC routine asked to terminate")
}
}
func (n *IRCNotifier) SetupPhase() {
if !n.Client.Connected() {
log.Printf("Connecting to IRC %s", n.Client.Config().Server)
if ok := n.BackoffCounter.DelayContext(n.stopCtx); !ok {
return
}
if err := n.Client.ConnectContext(n.stopCtx); err != nil {
log.Printf("Could not connect to IRC: %s", err)
return
}
log.Printf("Connected to IRC server, waiting to establish session")
}
select {
case <-n.sessionUpSignal:
n.sessionUp = true
n.MaybeIdentifyNick()
n.channelReconciler.JoinChannels()
ircConnectedGauge.Set(1)
case <-n.sessionDownSignal:
log.Printf("Receiving a session down before the session is up, this is odd")
case <-n.stopCtx.Done():
log.Printf("IRC routine asked to terminate")
}
}
func (n *IRCNotifier) Run() {
defer n.stopWg.Done()
for n.stopCtx.Err() != context.Canceled {
if !n.sessionUp {
n.SetupPhase()
} else {
n.ConnectedPhase()
}
}
n.ShutdownPhase()
}