Add link to Telegram

Ref #2

This commit adds a link to a Go Telegram API to send messages to a given
telegram channel provided with a JSON config file. At the moment the
program sends a simple status message to the bot when starting up, but
this allows testing whether the link to Telegram is correctly working.

tracker/bot/bot.go

@@ -0,0 +1,37 @@
+package bot
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"git.faercol.me/faercol/public-ip-tracker/tracker/config"
+	"github.com/ahugues/go-telegram-api/bot"
+)
+
+type Notifier struct {
+	ctx          context.Context
+	cancel       context.CancelFunc
+	tgBot        *bot.ConcreteBot
+	notifChannel int64
+}
+
+func (n *Notifier) SendInitMessage() error {
+	initMsg := fmt.Sprintf("Public IP tracked initialized at %v", time.Now())
+	if err := n.tgBot.SendMessage(n.ctx, n.notifChannel, initMsg); err != nil {
+		return fmt.Errorf("failed to send initialization message: %w", err)
+	}
+	return nil
+}
+
+func New(ctx context.Context, config *config.Config) *Notifier {
+	subCtx, cancel := context.WithCancel(ctx)
+	tgBot := bot.New(config.Telegram.Token)
+
+	return &Notifier{
+		ctx:          subCtx,
+		cancel:       cancel,
+		tgBot:        tgBot,
+		notifChannel: config.Telegram.ChannelID,
+	}
+}

tracker/config/config.go

@@ -0,0 +1,28 @@
+package config
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+)
+
+type TelegramConfig struct {
+	ChannelID int64  `json:"channel_id"`
+	Token     string `json:"token"`
+}
+
+type Config struct {
+	Telegram *TelegramConfig `json:"telegram"`
+}
+
+func New(filepath string) (*Config, error) {
+	content, err := os.ReadFile(filepath)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read config file %q: %w", filepath, err)
+	}
+	var conf Config
+	if err := json.Unmarshal(content, &conf); err != nil {
+		return nil, fmt.Errorf("failed to parse config file: %w", err)
+	}
+	return &conf, nil
+}

tracker/go.mod

@@ -1,3 +1,5 @@
 module git.faercol.me/faercol/public-ip-tracker/tracker
 
 go 1.16
+
+require github.com/ahugues/go-telegram-api v0.0.0-20230125191847-f1f02f942580

tracker/go.sum

@@ -0,0 +1,27 @@
+github.com/ahugues/go-telegram-api v0.0.0-20230125191847-f1f02f942580 h1:0EzaHeqTet8yPON8P6kHfHVl9Zb8+eWON0wPco93N7Y=
+github.com/ahugues/go-telegram-api v0.0.0-20230125191847-f1f02f942580/go.mod h1:8I/JWxd9GYM7dHOgGmkRI3Ei1u+nGvzeR2knIMmFw7E=
+github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
+github.com/yuin/goldmark v1.4.1/go.mod h1:mwnBkeHKe2W/ZEtQ+71ViKU8L12m81fl3OWwC1Zlc8k=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.5.1/go.mod h1:5OXOZSfqPIIbmVBIIKWRFfZjPR0E5r58TLhUjH0a2Ro=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20211015210444-4f30a5c0130f/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20210220032951-036812b2e83c/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+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 v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20211019181941-9d821ace8654/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
+golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.1.9/go.mod h1:nABZi5QlRsZVlzPpHl034qft6wpY4eDcsTt5AaioBiU=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20200804184101-5ec99f83aff1/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

tracker/main.go

@@ -1,11 +1,47 @@
 package main
 
-import "fmt"
+import (
+	"context"
+	"flag"
+	"fmt"
+
+	"git.faercol.me/faercol/public-ip-tracker/tracker/bot"
+	"git.faercol.me/faercol/public-ip-tracker/tracker/config"
+)
 
 func testMethod(a int) int {
 	return a + 2
 }
 
-func main() {
-	fmt.Println("public ip tracker")
+type cliArgs struct {
+	configPath string
+}
+
+func parseArgs() *cliArgs {
+	configPath := flag.String("config", "", "Path to the JSON configuration file")
+
+	flag.Parse()
+
+	return &cliArgs{
+		configPath: *configPath,
+	}
+}
+
+func main() {
+	fmt.Println("Parsing arguments")
+	args := parseArgs()
+
+	fmt.Println("Parsing config")
+	conf, err := config.New(args.configPath)
+	if err != nil {
+		panic(err)
+	}
+
+	fmt.Println("Initializing bot")
+	notifBot := bot.New(context.Background(), conf)
+	if err := notifBot.SendInitMessage(); err != nil {
+		panic(err)
+	}
+
+	fmt.Println("OK")
 }