Handle IRC server password

Introduce optional config parameter 'irc_host_password' to specify the
IRC server password.

Signed-off-by: Luca Bigliardi <shammash@google.com>

README.md

@@ -25,6 +25,8 @@ http_port: 8000
 # Note: SSL is enabled by default, use "irc_use_ssl: no" to disable.
 irc_host: irc.example.com
 irc_port: 7000
+# Optionally set the server password
+irc_host_password: myserver_password
 
 # Use this IRC nickname.
 irc_nickname: myalertbot

config.go

@@ -37,6 +37,7 @@ type Config struct {
 	IRCRealName  string       `yaml:"irc_realname"`
 	IRCHost      string       `yaml:"irc_host"`
 	IRCPort      int          `yaml:"irc_port"`
+	IRCHostPass  string       `yaml:"irc_host_password"`
 	IRCUseSSL    bool         `yaml:"irc_use_ssl"`
 	IRCVerifySSL bool         `yaml:"irc_verify_ssl"`
 	IRCChannels  []IRCChannel `yaml:"irc_channels"`
@@ -54,6 +55,7 @@ func LoadConfig(configFile string) (*Config, error) {
 		IRCRealName:  "Alertmanager IRC Relay",
 		IRCHost:      "example.com",
 		IRCPort:      7000,
+		IRCHostPass:  "",
 		IRCUseSSL:    true,
 		IRCVerifySSL: true,
 		IRCChannels:  []IRCChannel{},

config_test.go

@@ -40,6 +40,7 @@ func TestLoadGoodConfig(t *testing.T) {
 		IRCNick:     "foo",
 		IRCHost:     "irc.example.com",
 		IRCPort:     1234,
+		IRCHostPass: "hostsecret",
 		IRCUseSSL:   true,
 		IRCChannels: []IRCChannel{IRCChannel{Name: "#foobar"}},
 		MsgTemplate: defaultMsgTemplate,

irc.go

@@ -95,6 +95,7 @@ func NewIRCNotifier(config *Config, alertMsgs chan AlertMsg) (*IRCNotifier, erro
 	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,

irc_test.go

@@ -267,6 +267,46 @@ func TestPreJoinChannels(t *testing.T) {
 	}
 }
 
+func TestServerPassword(t *testing.T) {
+	server, port := makeTestServer(t)
+	config := makeTestIRCConfig(port)
+	config.IRCHostPass = "hostsecret"
+	notifier, _ := makeTestNotifier(t, config)
+
+	var testStep sync.WaitGroup
+
+	joinHandler := func(conn *bufio.ReadWriter, line *irc.Line) error {
+		// #baz is configured as the last channel to pre-join
+		if line.Args[0] == "#baz" {
+			testStep.Done()
+		}
+		return nil
+	}
+	server.SetHandler("JOIN", joinHandler)
+
+	testStep.Add(1)
+	go notifier.Run()
+
+	testStep.Wait()
+
+	notifier.StopRunning <- true
+	server.Stop()
+
+	expectedCommands := []string{
+		"PASS hostsecret",
+		"NICK foo",
+		"USER foo 12 * :",
+		"JOIN #foo",
+		"JOIN #bar",
+		"JOIN #baz",
+		"QUIT :see ya",
+	}
+
+	if !reflect.DeepEqual(expectedCommands, server.Log) {
+		t.Error("Did not send IRC server password")
+	}
+}
+
 func TestSendAlertOnPreJoinedChannel(t *testing.T) {
 	server, port := makeTestServer(t)
 	config := makeTestIRCConfig(port)