add prometheus metrics

.gitignore

@@ -1,3 +1,4 @@
 private
 go-discord-irc
 .vscode
+config_dev.yml

bridge/irc_manager.go

@@ -8,13 +8,22 @@ import (
 
 	"github.com/mozillazg/go-unidecode"
 	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
 
 	ircnick "github.com/qaisjp/go-discord-irc/irc/nick"
 	irc "github.com/qaisjp/go-ircevent"
 	log "github.com/sirupsen/logrus"
 )
 
-var DevMode = false
+var (
+	DevMode        = false
+	usersConnected = promauto.NewGauge(prometheus.GaugeOpts{
+		Namespace: "discord_irc",
+		Name:      "users_total",
+		Help:      "The total number of users connected from discord to irc",
+	})
+)
 
 // IRCManager should only be used from one thread.
 type IRCManager struct {
@@ -36,6 +45,7 @@ func newIRCManager(bridge *Bridge) *IRCManager {
 // CloseConnection shuts down a particular connection and its channels.
 func (m *IRCManager) CloseConnection(i *ircConnection) {
 	log.WithField("nick", i.nick).Println("Closing connection.")
+	usersConnected.Dec()
 	// Destroy the cooldown timer
 	if i.cooldownTimer != nil {
 		i.cooldownTimer.Stop()
@@ -205,6 +215,8 @@ func (m *IRCManager) HandleUser(user DiscordUser) {
 		fmt.Println("Incrementing total connections. It's now", len(m.ircConnections))
 	}
 
+	usersConnected.Inc()
+
 	err := con.innerCon.Connect(m.bridge.Config.IRCServer)
 	if err != nil {
 		log.WithField("error", err).Errorln("error opening irc connection")

config.yml

@@ -25,3 +25,7 @@ no_tls: false
 debug: false
 webhook_prefix: "(auto-test)"
 # simple: true
+
+prometheus:
+  enabled: false  # Disabled by default
+  # port: 2112

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/hashicorp/go-multierror v1.0.0
 	github.com/mozillazg/go-unidecode v0.1.1
 	github.com/pkg/errors v0.8.1
+	github.com/prometheus/client_golang v0.9.3
 	github.com/qaisjp/go-ircevent v0.0.0-20180911155239-e71f5fec2a8d
 	github.com/sirupsen/logrus v1.4.2
 	github.com/spf13/viper v1.4.0

go.sum

@@ -6,6 +6,7 @@ github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuy
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/beorn7/perks v1.0.0 h1:HWo1m869IqiPhD389kmkxeTalrjNbbJTC8LXupb+sl0=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/bwmarrin/discordgo v0.20.2 h1:nA7jiTtqUA9lT93WL2jPjUp8ZTEInRujBdx1C9gkr20=
 github.com/bwmarrin/discordgo v0.20.2/go.mod h1:O9S4p+ofTFwB02em7jkpkV8M3R0/PUVOwN61zSZ0r4Q=
@@ -37,36 +38,32 @@ github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfU
 github.com/golang/groupcache v0.0.0-20190129154638-5b532d6fd5ef/go.mod h1:cIg4eruTrX1D+g88fzRXU5OdNfaM+9IcxsU14FzY7Hc=
 github.com/golang/mock v1.1.1/go.mod h1:oTYuIxOrZwtPieC+H1uAHpcLFnEyAGVDL/k47Jfbm0A=
 github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.1 h1:YF8+flBXS5eO826T4nzqPrxfhQThhXl0YzfuUPu4SBg=
 github.com/golang/protobuf v1.3.1/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
 github.com/google/btree v1.0.0/go.mod h1:lNA+9X1NB3Zf8V7Ke586lFgjr2dZNuvo3lPJSGZ5JPQ=
 github.com/google/go-cmp v0.2.0/go.mod h1:oXzfMopK8JAjlY9xF4vHSVASa0yLyX7SntLO5aqRK0M=
-github.com/gorilla/websocket v1.4.0 h1:WDFjx/TMzVgy9VdMMQi2K2Emtwi2QcUQsztZ/zLaH/Q=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
 github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
 github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
-github.com/hashicorp/errwrap v1.0.0 h1:hLrqtEDnRye3+sgx6z4qVLNuviH3MR5aQ0ykNJa/UYA=
 github.com/hashicorp/errwrap v1.0.0/go.mod h1:YH+1FKiLXxHSkmPseP+kNlulaMuP3n2brvKWEqk/Jc4=
-github.com/hashicorp/go-multierror v1.0.0 h1:iVjPR7a6H0tWELX5NxNe7bYopibicUzc7uPribsnS6o=
 github.com/hashicorp/go-multierror v1.0.0/go.mod h1:dHtQlpGsu+cZNNAkkCN/P3hoUDHhCYQXV3UM06sGGrk=
 github.com/hashicorp/hcl v1.0.0 h1:0Anlzjpi4vEasTeNFn2mLJgTSwt0+6sfsiTG8qcWGx4=
 github.com/hashicorp/hcl v1.0.0/go.mod h1:E5yfLk+7swimpb2L/Alb/PJmXilQ/rhwaUYs4T20WEQ=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
-github.com/konsorten/go-windows-terminal-sequences v1.0.1 h1:mweAR1A6xJ3oS2pRaGiHgQ4OO8tzTaLawm8vnODuwDk=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
-github.com/kr/pretty v0.1.0 h1:L/CwN0zerZDmRFUapSPitk6f+Q3+0za1rQkzVuMiMFI=
 github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
-github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/magiconair/properties v1.8.0 h1:LLgXmsheXeRoUOBOjtwPQCWIYqM/LU1ayDtDePerRcY=
 github.com/magiconair/properties v1.8.0/go.mod h1:PppfXfuXeibc/6YijjN8zIbojt8czPbwD3XqdrwzmxQ=
+github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
@@ -82,12 +79,16 @@ github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINE
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_golang v0.9.3 h1:9iH4JKXLzFbOAdtqv/a+j8aewx2Y8lAjAydhbaScPF8=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 h1:S/YWwWx/RA8rT8tKFRuGUZhuA90OyIBpPCXkcbwU8DE=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/common v0.4.0 h1:7etb9YClo3a6HjLzfl6rIQaU+FDfi0VSX39io3aQ+DM=
 github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084 h1:sofwID9zm4tzrgykg80hfFph1mryUeLRsUfoocVVmRY=
 github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
 github.com/qaisjp/go-ircevent v0.0.0-20180911155239-e71f5fec2a8d h1:I1q/elCk4+7JBvJwIf/CmiShndsTu0ka2diGjL0dV20=
@@ -121,12 +122,7 @@ go.uber.org/multierr v1.1.0/go.mod h1:wR5kodmAFQ0UK8QlbwjlSNy0Z68gJhDJUG5sjR94q/
 go.uber.org/zap v1.10.0/go.mod h1:vwi/ZaCAaUcBkycHslxD9B2zi4UTXhF60s6SWpuDF0Q=
 golang.org/x/crypto v0.0.0-20180904163835-0709b304e793/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
 golang.org/x/crypto v0.0.0-20181030102418-4d3f4d9ffa16/go.mod h1:6SG95UA2DQfeDnfUPMdvaQW0Q7yPrPDi9nlGo2tz2b4=
-golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2 h1:VklqNMn3ovrHsnt90PveolxSbWFaJdECFbxSq0Mqo2M=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/crypto v0.0.0-20200323165209-0ec3e9974c59 h1:3zb4D3T4G8jdExgVU/95+vQXfpEPiMdCaZgmGVxjNHM=
-golang.org/x/crypto v0.0.0-20200323165209-0ec3e9974c59/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
-golang.org/x/crypto v0.0.0-20201112155050-0c6587e931a9 h1:umElSU9WZirRdgu2yFHY0ayQkEnKiOC1TtM3fWXFnoU=
-golang.org/x/crypto v0.0.0-20201112155050-0c6587e931a9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9 h1:phUcVbl53swtrUN8kQEXFhUxPlIlWyBfKmidCu7P95o=
 golang.org/x/crypto v0.0.0-20201117144127-c1f2f97bffc9/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -146,14 +142,8 @@ golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20181107165924-66b7b1311ac8/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20181116152217-5ac8a444bdc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
-golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190422165155-953cdadca894 h1:Cz4ceDQGXuKRnVBDTS23GTn/pU5OE2C0WrNTOYK1Uuc=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd h1:xhmwyvizuTgC2qz7ZlMluP20uW+C3Rm0FD/WLDX8884=
-golang.org/x/sys v0.0.0-20200323222414-85ca7c5b95cd/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20201113233024-12cec1faf1ba h1:xmhUJGQGbxlod18iJGqVEp9cHIPLl7QiX2aA3to708s=
-golang.org/x/sys v0.0.0-20201113233024-12cec1faf1ba/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
@@ -169,7 +159,6 @@ google.golang.org/grpc v1.19.0/go.mod h1:mqu4LbDTu4XGKhr4mRzUsmM4RtVoemTSY81AxZi
 google.golang.org/grpc v1.21.0/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/resty.v1 v1.12.0/go.mod h1:mDo4pnntr5jdWRML875a/NmxYqAlA73dVijT2AXvQQo=
 gopkg.in/yaml.v2 v2.0.0-20170812160011-eb3733d160e7/go.mod h1:JAlM8MvJe8wmxCU4Bli9HhUf9+ttbYbLASfIpnQbh74=

main.go

@@ -2,16 +2,19 @@ package main
 
 import (
 	"flag"
+	"net/http"
 	"os"
 	"os/signal"
 	"path/filepath"
 	"reflect"
+	"strconv"
 	"strings"
 	"syscall"
 	"time"
 
 	"github.com/fsnotify/fsnotify"
 	"github.com/pkg/errors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/qaisjp/go-discord-irc/bridge"
 	ircnick "github.com/qaisjp/go-discord-irc/irc/nick"
 	log "github.com/sirupsen/logrus"
@@ -34,6 +37,7 @@ func main() {
 
 	if *config == "" {
 		log.Fatalln("--config argument is required!")
+
 		return
 	}
 
@@ -46,6 +50,7 @@ func main() {
 	configName := strings.TrimSuffix(filepath.Base(*config), ext)
 	configType := ext[1:]
 	configPath := filepath.Dir(*config)
+
 	viper.SetConfigName(configName)
 	viper.SetConfigType(configType)
 	viper.AddConfigPath(configPath)
@@ -61,13 +66,20 @@ func main() {
 		log.Fatalln(errors.Wrap(err, "could not read config"))
 	}
 
-	discordBotToken := viper.GetString("discord_token")             // Discord Bot User Token
-	channelMappings := viper.GetStringMapString("channel_mappings") // Discord:IRC mappings in format '#discord1:#irc1,#discord2:#irc2,...'
-	ircServer := viper.GetString("irc_server")                      // Server address to use, example `irc.freenode.net:7000`.
-	ircPassword := viper.GetString("irc_pass")                      // Optional password for connecting to the IRC server
-	guildID := viper.GetString("guild_id")                          // Guild to use
-	webIRCPass := viper.GetString("webirc_pass")                    // Password for WEBIRC
-	identify := viper.GetString("nickserv_identify")                // NickServ IDENTIFY for Listener
+	// Discord Bot User Token
+	discordBotToken := viper.GetString("discord_token")
+	// Discord:IRC mappings in format '#discord1:#irc1,#discord2:#irc2,...'
+	channelMappings := viper.GetStringMapString("channel_mappings")
+	// Server address to use, example `irc.freenode.net:7000`.
+	ircServer := viper.GetString("irc_server")
+	// Optional password for connecting to the IRC server
+	ircPassword := viper.GetString("irc_pass")
+	// Guild to use
+	guildID := viper.GetString("guild_id")
+	// Password for WEBIRC
+	webIRCPass := viper.GetString("webirc_pass")
+	// NickServ IDENTIFY for Listener
+	identify := viper.GetString("nickserv_identify")
 	//
 	if !*debugMode {
 		*debugMode = viper.GetBool("debug")
@@ -76,6 +88,7 @@ func main() {
 	if !*notls {
 		*notls = viper.GetBool("no_tls")
 	}
+	//
 	if !*insecure {
 		*insecure = viper.GetBool("insecure")
 	}
@@ -103,6 +116,11 @@ func main() {
 	viper.SetDefault("max_nick_length", ircnick.MAXLENGTH)
 	maxNickLength := viper.GetInt("max_nick_length")
 
+	viper.SetDefault("prometheus.enabled", false)
+	viper.SetDefault("prometheus.port", 2112)
+	promEnabled := viper.GetBool("prometheus.enabled")
+	metricsPort := viper.GetInt("prometheus.port")
+
 	if webIRCPass == "" {
 		log.Warnln("webirc_pass is empty")
 	}
@@ -112,7 +130,11 @@ func main() {
 		log.Warnln("Channel mappings are missing!")
 	}
 
-	SetLogDebug(*debugMode)
+	setLogDebug(*debugMode)
+
+	if promEnabled {
+		enableMetrics(metricsPort)
+	}
 
 	dib, err := bridge.New(&bridge.Config{
 		DiscordBotToken:    discordBotToken,
@@ -140,6 +162,7 @@ func main() {
 
 	if err != nil {
 		log.WithField("error", err).Fatalln("Go-Discord-IRC failed to initialise.")
+
 		return
 	}
 
@@ -153,6 +176,7 @@ func main() {
 	err = dib.Open()
 	if err != nil {
 		log.WithField("error", err).Fatalln("Go-Discord-IRC failed to start.")
+
 		return
 	}
 
@@ -174,7 +198,7 @@ func main() {
 			log.Printf("Debug changed from %+v to %+v", *debugMode, debug)
 			*debugMode = debug
 			dib.SetDebugMode(debug)
-			SetLogDebug(debug)
+			setLogDebug(debug)
 		}
 
 		chans := viper.GetStringMapString("channel_mappings")
@@ -202,11 +226,29 @@ func main() {
 	dib.Close()
 }
 
-func SetLogDebug(debug bool) {
+func setLogDebug(debug bool) {
 	logger := log.StandardLogger()
+
 	if debug {
 		logger.SetLevel(log.DebugLevel)
 	} else {
 		logger.SetLevel(log.InfoLevel)
 	}
 }
+
+func enableMetrics(port int) {
+	http.Handle("/metrics", promhttp.Handler())
+
+	portStr := strconv.Itoa(port)
+	address := ":" + portStr
+
+	go func() {
+		if err := http.ListenAndServe(address, nil); err != nil {
+			log.WithFields(log.Fields{
+				"error":   err,
+				"address": address,
+			}).Error("could not start prometheus metric endpoint")
+		}
+	}()
+	log.WithField("address", address).Info("prometheus metric endpoint started")
+}