about summary refs log tree commit diff
path: root/fun/clbot/clbot.go
blob: 222ce07788d976861aad1dc828caaf3717b7b9f4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
package main

import (
	"context"
	"crypto/tls"
	"flag"
	"fmt"
	"io/ioutil"
	"os"
	"os/signal"
	"strings"
	"time"

	"code.tvl.fyi/fun/clbot/backoffutil"
	"code.tvl.fyi/fun/clbot/gerrit"
	"code.tvl.fyi/fun/clbot/gerrit/gerritevents"
	log "github.com/golang/glog"
	"golang.org/x/crypto/ssh"
	"gopkg.in/irc.v3"
)

var (
	gerritAddr       = flag.String("gerrit_host", "cl.tvl.fyi:29418", "Gerrit SSH host:port")
	gerritSSHHostKey = flag.String("gerrit_ssh_pubkey", "ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBIUNYBYPCCBNDFSd0BuCR+8kgeuJ7IA5S2nTNQmkQUYNyXK+ot5os7rHtCk96+grd5+J8jFCuFBWisUe8h8NC0Q=", "Gerrit SSH public key")
	gerritSSHTimeout = flag.Duration("gerrit_tcp_timeout", 5*time.Second, "Gerrit SSH TCP connect timeout")

	gerritAuthUsername = flag.String("gerrit_ssh_auth_username", "", "Gerrit SSH username")
	gerritAuthKeyPath  = flag.String("gerrit_ssh_auth_key", "", "Gerrit SSH private key path")

	ircServer    = flag.String("irc_server", "chat.freenode.net:7000", "IRC server to connect to")
	ircNick      = flag.String("irc_nick", "clbot", "Nick to use when connecting to IRC")
	ircUser      = flag.String("irc_user", "clbot", "User string to use for IRC")
	ircName      = flag.String("irc_name", "clbot", "Name string to use for IRC")
	ircChannel   = flag.String("irc_channel", "##tvl", "Channel to send messages to")
	ircPassword  = flag.String("irc_pass", "", "Password to use for IRC")
	ircSendLimit = flag.Duration("irc_send_limit", 100*time.Millisecond, "Delay between messages")
	ircSendBurst = flag.Int("irc_send_burst", 10, "Number of messages which can be sent in a burst")
)

func mustFixedHostKey(f string) ssh.HostKeyCallback {
	pk, _, _, _, err := ssh.ParseAuthorizedKey([]byte(f))
	if err != nil {
		log.Exitf("ParseAuthorizedKey(%q): %v", f, err)
	}
	return ssh.FixedHostKey(pk)
}

func mustPrivateKey(p string) ssh.AuthMethod {
	pkBytes, err := ioutil.ReadFile(p)
	if err != nil {
		log.Exitf("reading SSH private key from %q: %v", p, err)
	}
	pk, err := ssh.ParsePrivateKey(pkBytes)
	if err != nil {
		log.Exitf("parsing private key from %q: %v", p, err)
	}
	return ssh.PublicKeys(pk)
}

var shutdownFuncs []func()

func callOnShutdown(f func()) {
	shutdownFuncs = append(shutdownFuncs, f)
}

// Unicode U+200B zero-width-space, to avoid triggering other bots
// or highlighting people on IRC.
const zeroWidthSpace = "\u200b"

func runIRC(ctx context.Context, ircCfg irc.ClientConfig, sendMsg <-chan string) {
	bo := backoffutil.NewDefaultBackOff()
	ircCfg.Handler = irc.HandlerFunc(func(c *irc.Client, m *irc.Message) {
		if m.Command == "NOTICE" && m.Prefix.Name == "NickServ" && strings.Contains(m.Trailing(), "dentified") {
			// We're probably identified now, go join the channel.
			c.Writef("JOIN %s", *ircChannel)
		}
	})
	for {
		timer := time.NewTimer(bo.NextBackOff())
		select {
		case <-ctx.Done():
			timer.Stop()
			return
		case <-timer.C:
			break
		}

		(func() {
			connectedStart := time.Now()
			ircConn, err := tls.Dial("tcp", *ircServer, nil)
			if err != nil {
				log.Errorf("connecting to IRC at tcp/%s: %v", *ircServer, err)
				return
			}
			ircClient := irc.NewClient(ircConn, ircCfg)
			ircClientCtx, cancel := context.WithCancel(ctx)
			defer cancel()
			go func() {
				for {
					select {
					case <-ircClientCtx.Done():
						return
					case msg := <-sendMsg:
						log.Infof("sending message %q to %v", msg, *ircChannel)
						ircClient.Writef("PRIVMSG %s :%s%s", *ircChannel, zeroWidthSpace, msg)
					}
				}
			}()
			log.Infof("connecting to IRC on tcp/%s", *ircServer)
			if err := ircClient.RunContext(ircClientCtx); err != nil {
				connectedEnd := time.Now()
				connectedFor := connectedEnd.Sub(connectedStart)
				if connectedFor > 60*time.Second {
					bo.Reset()
				}
				log.Errorf("IRC RunContext: %v", err)
				return
			}
		})()
	}
}

func username(p gerritevents.PatchSet) string {
	options := []string{
		p.Uploader.Username,
		p.Uploader.Name,
		p.Uploader.Email,
	}
	for _, opt := range options {
		if opt != "" {
			return opt
		}
	}
	return "UNKNOWN USER"
}

// noping inserts a Unicode zero-width space between the first and rest characters of `user`
// in an effort to avoid pinging that user on IRC.
func noping(user string) string {
	return fmt.Sprintf("%s%s%s", user[0], zeroWidthSpace, user[1:])
}

func patchSetURL(c gerritevents.Change, p gerritevents.PatchSet) string {
	return fmt.Sprintf("https://cl.tvl.fyi/%d", c.Number)
}

func main() {
	flag.Parse()
	failed := false
	if *gerritAuthUsername == "" {
		log.Errorf("gerrit_ssh_auth_username must be set")
		failed = true
	}
	if *gerritAuthKeyPath == "" {
		log.Errorf("gerrit_ssh_auth_key must be set")
		failed = true
	}
	if failed {
		os.Exit(2)
	}

	shutdownCh := make(chan os.Signal)
	signal.Notify(shutdownCh, os.Interrupt)
	go func() {
		<-shutdownCh
		signal.Reset(os.Interrupt)
		for n := len(shutdownFuncs) - 1; n >= 0; n-- {
			shutdownFuncs[n]()
		}
	}()

	ctx, cancel := context.WithCancel(context.Background())
	callOnShutdown(cancel)
	cfg := &ssh.ClientConfig{
		User:            *gerritAuthUsername,
		Auth:            []ssh.AuthMethod{mustPrivateKey(*gerritAuthKeyPath)},
		HostKeyCallback: mustFixedHostKey(*gerritSSHHostKey),
		Timeout:         *gerritSSHTimeout,
	}
	cfg.SetDefaults()

	gw, err := gerrit.New(ctx, "tcp", *gerritAddr, cfg)
	if err != nil {
		log.Exitf("gerrit.New(%q): %v", *gerritAddr, err)
	}
	callOnShutdown(func() {
		ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
		defer cancel()
		gw.Close(ctx)
	})

	sendMsgChan := make(chan string, 5)
	go func() {
		for e := range gw.Events() {
			var parsedMsg string
			switch e := e.(type) {
			case *gerritevents.PatchSetCreated:
				if e.Change.Project != "depot" || e.Change.Branch != "master" || e.PatchSet.Number != 1 {
					continue
				}
				parsedMsg = fmt.Sprintf("CL/%d: %q proposed by %s - %s", e.Change.Number, e.Change.Subject, noping(username(e.PatchSet)), patchSetURL(e.Change, e.PatchSet))
			case *gerritevents.ChangeMerged:
				if e.Change.Project != "depot" || e.Change.Branch != "master" {
					continue
				}
				parsedMsg = fmt.Sprintf("CL/%d: %q submitted by %s - %s", e.Change.Number, e.Change.Subject, noping(username(e.PatchSet)), patchSetURL(e.Change, e.PatchSet))
			}
			if parsedMsg != "" {
				sendMsgChan <- parsedMsg
			}
		}
	}()

	ircCtx, ircCancel := context.WithCancel(ctx)
	callOnShutdown(ircCancel)
	go runIRC(ircCtx, irc.ClientConfig{
		Nick: *ircNick,
		User: *ircUser,
		Name: *ircName,
		Pass: *ircPassword,

		SendLimit: *ircSendLimit,
		SendBurst: *ircSendBurst,
	}, sendMsgChan)

	<-ctx.Done()
}