- Add configurable retries for do-retry with default of 3 (alerting,

  mails, scraping)
- Log maxprocs failures through logrus

README.md

@@ -60,7 +60,7 @@ Za instalaciju dovoljno je skinuti izvršnu datoteku sa [releases](https://githu
 ### Usage / Upute za upotrebu
 
 ```shell
-Usage: e-dnevnik-bot [-?dtv] [-b value] [-f value] [-i value] [parameters ...]
+Usage: e-dnevnik-bot [-?dtv] [-b value] [-f value] [-i value] [-r value] [parameters ...]
  -?, --help     display help
  -b, --database=value
                 alert database file [.e-dnevnik.db]
@@ -69,6 +69,8 @@ Usage: e-dnevnik-bot [-?dtv] [-b value] [-f value] [-i value] [parameters ...]
                 configuration file (in TOML) [.e-dnevnik.toml]
  -i, --interval=value
                 interval between polls when in daemon mode [1h]
+ -r, --retries=value
+                default retry attempts on error [3]
  -t, --test     send a test event (to check if messaging works)
  -v, --verbose  enable verbose/debug log level
 ```
@@ -81,6 +83,7 @@ Other flags are:
 - `-d`: enable daemon mode aka service mode where bot works continously, waking up on regular intervals (specified with `-i`) and by default this is disabled,
 - `-f`: configuration file path to configure usernames, passwords and various messaging services (in [TOML](https://github.com/toml-lang/toml) format),
 - `-i`: interval between polls when in daemon/service mode (at minimum 1h, default 1h),
+- `-r`: retries between unsuccessful attempts to scrape and/or send alerts (default 3),
 - `-t`: sends a test message to all configured messaging services,
 - `-v`: enables verbose/debug messages for more insight into bot operation and by default this is disabled.
 
@@ -94,6 +97,7 @@ Ostali parametri su:
 - `-d`: omogućuje servisni rad gdje bot radi kontinuirano i budi se u regularnim intervalima (koje odabiremo sa `-i` parametrom) te je ovakav način rada standardno ugašen,
 - `-f`: staza do konfiguracijske datoteke koja sadrži korisnička imena, lozinke i ostalu konfiguraciju za servise slanja poruka odnosno e-maila (u [TOML](https://github.com/toml-lang/toml) sintaksi),
 - `-i`: interval između buđenja bota (minimalno 1h, standardno 1h),
+- `-r`: broj pokušaja kod neuspjeha prilikom dohvata ocjena i/ili slanja poruka odnosno e-mailova,
 - `-t`: služi za slanje testne poruke na sve konfigurirane servise slanja poruka odnosno e-maila,
 - `-v`: omogućuje prikaz više informacija o radu servisa, te je standardno ova opcija ugašena.
 

flags.go

@@ -33,12 +33,14 @@ import (
 const (
 	DefaultConfFile     = ".e-dnevnik.toml" // default configuration filename
 	DefaultTickInterval = "1h"              // default (and minimal permitted value) is 1 tick per 1h
+	DefaultRetries      = 3                 // default retry attempts
 )
 
 var (
 	debug, daemon, help, emulation       *bool
 	confFile, dbFile, tickIntervalString *string
 	tickInterval                         time.Duration
+	retries                              *uint
 )
 
 // init initializes flags configuration.
@@ -51,6 +53,7 @@ func init() {
 	dbFile = getopt.StringLong("database", 'b', db.DefaultDBPath, "alert database file")
 	tickIntervalString = getopt.StringLong("interval", 'i', DefaultTickInterval,
 		"interval between polls when in daemon mode")
+	retries = getopt.UintLong("retries", 'r', DefaultRetries, "default retry attempts on error")
 }
 
 // parseFlags parses input arguments and flags.

main.go

@@ -23,6 +23,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"os"
 	"os/signal"
 	"sync"
@@ -36,7 +37,7 @@ import (
 
 	_ "github.com/KimMachineGun/automemlimit"
 	"github.com/dkorunic/e-dnevnik-bot/msgtypes"
-	_ "go.uber.org/automaxprocs"
+	"go.uber.org/automaxprocs/maxprocs"
 )
 
 const (
@@ -49,7 +50,10 @@ const (
 	testField          = "Testna vrijednost"
 )
 
-var exitWithError atomic.Bool
+var (
+	exitWithError atomic.Bool
+	ErrMaxProc    = errors.New("failed to set GOMAXPROCS")
+)
 
 func main() {
 	parseFlags()
@@ -66,6 +70,13 @@ func main() {
 		logrus.SetLevel(logrus.DebugLevel)
 	}
 
+	// auto-configure GOMAXPROCS
+	undo, err := maxprocs.Set()
+	defer undo()
+	if err != nil {
+		logrus.Warnf("%v: %v", ErrMaxProc, err)
+	}
+
 	// context with signal integration
 	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
 	defer stop()

messenger/discord.go

@@ -53,7 +53,7 @@ var (
 
 // Discord messenger processes events from a channel and attempts to communicate to one or more UserIDs, optionally
 // returning an error.
-func Discord(ctx context.Context, ch <-chan interface{}, token string, userIDs []string) error {
+func Discord(ctx context.Context, ch <-chan interface{}, token string, userIDs []string, retries uint) error {
 	if token == "" {
 		return fmt.Errorf("%w", ErrDiscordEmptyAPIKey)
 	}
@@ -124,6 +124,7 @@ func Discord(ctx context.Context, ch <-chan interface{}, token string, userIDs [
 
 						return err
 					},
+					retry.Attempts(retries),
 					retry.Context(ctx),
 				)
 				if err != nil {

messenger/mail.go

@@ -47,7 +47,7 @@ var (
 // Mail messenger processes events from a channel and attempts to send emails to one or more recipients,
 // optionally returning an error.
 func Mail(ctx context.Context, ch <-chan interface{}, server, port, username, password, from, subject string,
-	to []string,
+	to []string, retries uint,
 ) error {
 	logrus.Debug("Sending message through mail service")
 
@@ -94,6 +94,7 @@ func Mail(ctx context.Context, ch <-chan interface{}, server, port, username, pa
 					func() error {
 						return d.DialAndSend(m)
 					},
+					retry.Attempts(retries),
 					retry.Context(ctx),
 				)
 				if err != nil {

messenger/slack.go

@@ -46,7 +46,7 @@ var (
 
 // Slack messenger processes events from a channel and attempts to communicate to one or more ChatIDs, optionally
 // returning an error.
-func Slack(ctx context.Context, ch <-chan interface{}, token string, chatIDs []string) error {
+func Slack(ctx context.Context, ch <-chan interface{}, token string, chatIDs []string, retries uint) error {
 	if token == "" {
 		return fmt.Errorf("%w", ErrSlackEmptyAPIKey)
 	}
@@ -89,6 +89,7 @@ func Slack(ctx context.Context, ch <-chan interface{}, token string, chatIDs []s
 
 						return err
 					},
+					retry.Attempts(retries),
 					retry.Context(ctx),
 				)
 				if err != nil {

messenger/telegram.go

@@ -50,7 +50,7 @@ var (
 
 // Telegram messenger processes events from a channel and attempts to communicate to one or more ChatIDs, optionally
 // returning an error.
-func Telegram(ctx context.Context, ch <-chan interface{}, apiKey string, chatIDs []string) error {
+func Telegram(ctx context.Context, ch <-chan interface{}, apiKey string, chatIDs []string, retries uint) error {
 	if apiKey == "" {
 		return fmt.Errorf("%w", ErrTelegramEmptyAPIKey)
 	}
@@ -106,6 +106,7 @@ func Telegram(ctx context.Context, ch <-chan interface{}, apiKey string, chatIDs
 
 						return err
 					},
+					retry.Attempts(retries),
 					retry.Context(ctx),
 				)
 				if err != nil {

routines.go

@@ -61,7 +61,7 @@ func scrapers(ctx context.Context, wgScrape *sync.WaitGroup, gradesScraped chan<
 		go func() {
 			defer wgScrape.Done()
 
-			err := scrape.GetGradesAndEvents(ctx, gradesScraped, i.Username, i.Password)
+			err := scrape.GetGradesAndEvents(ctx, gradesScraped, i.Username, i.Password, *retries)
 			if err != nil {
 				logrus.Warnf("%v %v: %v", ErrScrapingUser, i.Username, err)
 				exitWithError.Store(true)
@@ -89,7 +89,7 @@ func msgSend(ctx context.Context, wgMsg *sync.WaitGroup, gradesMsg <-chan msgtyp
 			go func() {
 				defer wgMsg.Done()
 				logrus.Debug("Discord messenger started")
-				if err := messenger.Discord(ctx, ch, config.Discord.Token, config.Discord.UserIDs); err != nil {
+				if err := messenger.Discord(ctx, ch, config.Discord.Token, config.Discord.UserIDs, *retries); err != nil {
 					logrus.Warnf("%v: %v", ErrDiscord, err)
 					exitWithError.Store(true)
 				}
@@ -107,7 +107,7 @@ func msgSend(ctx context.Context, wgMsg *sync.WaitGroup, gradesMsg <-chan msgtyp
 			go func() {
 				defer wgMsg.Done()
 				logrus.Debug("Telegram messenger started")
-				if err := messenger.Telegram(ctx, ch, config.Telegram.Token, config.Telegram.ChatIDs); err != nil {
+				if err := messenger.Telegram(ctx, ch, config.Telegram.Token, config.Telegram.ChatIDs, *retries); err != nil {
 					logrus.Warnf("%v: %v", ErrTelegram, err)
 					exitWithError.Store(true)
 				}
@@ -125,7 +125,7 @@ func msgSend(ctx context.Context, wgMsg *sync.WaitGroup, gradesMsg <-chan msgtyp
 			go func() {
 				defer wgMsg.Done()
 				logrus.Debug("Slack messenger started")
-				if err := messenger.Slack(ctx, ch, config.Slack.Token, config.Slack.ChatIDs); err != nil {
+				if err := messenger.Slack(ctx, ch, config.Slack.Token, config.Slack.ChatIDs, *retries); err != nil {
 					logrus.Warnf("%v: %v", ErrSlack, err)
 					exitWithError.Store(true)
 				}
@@ -144,7 +144,7 @@ func msgSend(ctx context.Context, wgMsg *sync.WaitGroup, gradesMsg <-chan msgtyp
 				defer wgMsg.Done()
 				logrus.Debug("Mail messenger started")
 				if err := messenger.Mail(ctx, ch, config.Mail.Server, config.Mail.Port, config.Mail.Username,
-					config.Mail.Password, config.Mail.From, config.Mail.Subject, config.Mail.To); err != nil {
+					config.Mail.Password, config.Mail.From, config.Mail.Subject, config.Mail.To, *retries); err != nil {
 					logrus.Warnf("%v: %v", ErrMail, err)
 					exitWithError.Store(true)
 				}

scrape/scrape.go

@@ -23,23 +23,19 @@ package scrape
 
 import (
 	"context"
+	"time"
 
 	"github.com/dkorunic/e-dnevnik-bot/fetch"
 	"github.com/dkorunic/e-dnevnik-bot/msgtypes"
 
 	"github.com/avast/retry-go/v4"
 )
 
-const (
-	defaultScrapeTimeout = fetch.Timeout * defaultAttempts // max time permitted for all attempts
-	defaultAttempts      = 10                              // total number of full csrf/auth/fetch attempts
-)
-
 // GetGradesAndEvents initiates fetching subjects, grades and exam events from remote e-dnevnik site, sends
 // individual messages to a message channel and optionally returning an error.
-func GetGradesAndEvents(ctx context.Context, ch chan<- msgtypes.Message, username, password string) error {
+func GetGradesAndEvents(ctx context.Context, ch chan<- msgtypes.Message, username, password string, retries uint) error {
 	err := func() error {
-		ctx, stop := context.WithTimeout(ctx, defaultScrapeTimeout)
+		ctx, stop := context.WithTimeout(ctx, time.Duration(retries)*fetch.Timeout)
 		defer stop()
 
 		client, err := fetch.NewClientWithContext(ctx, username, password)
@@ -57,7 +53,7 @@ func GetGradesAndEvents(ctx context.Context, ch chan<- msgtypes.Message, usernam
 
 				return err
 			},
-			retry.Attempts(defaultAttempts),
+			retry.Attempts(retries),
 			retry.Context(ctx),
 		)
 		if err != nil {