refactor: rewrite code using Go 1.23 iterators (#911)

.golangci.yaml

@@ -10,6 +10,8 @@ linters-settings:
     settings:
       printf:
         funcs:
+          - github.com/favonia/cloudflare-ddns/internal/message.NewMonitorMessagef
+          - github.com/favonia/cloudflare-ddns/internal/message.NewNotifierMessagef
           - (github.com/favonia/cloudflare-ddns/internal/pp.PP).Infof
           - (github.com/favonia/cloudflare-ddns/internal/pp.PP).Noticef
           - (github.com/favonia/cloudflare-ddns/internal/pp.PP).Hintf
@@ -39,6 +41,7 @@ linters:
   disable:
     - execinquery # deprecated
     - gomnd # deprecated
+    - exportloopref # deprecated
 
     - cyclop # can detect complicated code, but never leads to actual code changes
     - funlen # can detect complicated code, but never leads to actual code changes

cmd/ddns/ddns.go

@@ -57,8 +57,8 @@ func initConfig(ppfmt pp.PP) (*config.Config, setter.Setter, bool) {
 func stopUpdating(ctx context.Context, ppfmt pp.PP, c *config.Config, s setter.Setter) {
 	if c.DeleteOnStop {
 		msg := updater.DeleteIPs(ctx, ppfmt, c, s)
-		monitor.LogMessageAll(ctx, ppfmt, c.Monitors, msg.MonitorMessage)
-		notifier.SendMessageAll(ctx, ppfmt, c.Notifiers, msg.NotifierMessage)
+		c.Monitor.Log(ctx, ppfmt, msg.MonitorMessage)
+		c.Notifier.Send(ctx, ppfmt, msg.NotifierMessage)
 	}
 }
 
@@ -89,18 +89,18 @@ func realMain() int { //nolint:funlen
 	// Read the config and get the handler and the setter
 	c, s, configOK := initConfig(ppfmt)
 	// Ping monitors regardless of whether initConfig succeeded
-	monitor.StartAll(ctx, ppfmt, c.Monitors, formatName())
+	c.Monitor.Start(ctx, ppfmt, formatName())
 	// Bail out now if initConfig failed
 	if !configOK {
-		monitor.ExitStatusAll(ctx, ppfmt, c.Monitors, 1, "Configuration errors")
-		notifier.SendAll(ctx, ppfmt, c.Notifiers,
-			"Cloudflare DDNS was misconfigured and could not start. Please check the logging for details.")
+		c.Monitor.Ping(ctx, ppfmt, monitor.NewMessagef(false, "Configuration errors"))
+		c.Notifier.Send(ctx, ppfmt, notifier.NewMessagef(
+			"Cloudflare DDNS was misconfigured and could not start. Please check the logging for details."))
 		ppfmt.Infof(pp.EmojiBye, "Bye!")
 		return 1
 	}
 	// If UPDATE_CRON is not `@once` (not single-run mode), then send a notification to signal the start.
 	if c.UpdateCron != nil {
-		notifier.SendAll(ctx, ppfmt, c.Notifiers, "Started running Cloudflare DDNS.")
+		c.Notifier.Send(ctx, ppfmt, notifier.NewMessagef("Started running Cloudflare DDNS."))
 	}
 
 	// Without the following line, the quiet mode can be too quiet, and some system (Portainer)
@@ -122,11 +122,11 @@ func realMain() int { //nolint:funlen
 
 		// Update the IP addresses
 		if first && !c.UpdateOnStart {
-			monitor.SuccessAll(ctx, ppfmt, c.Monitors, "Started (no action)")
+			c.Monitor.Ping(ctx, ppfmt, monitor.NewMessagef(true, "Started (no action)"))
 		} else {
 			msg := updater.UpdateIPs(ctxWithSignals, ppfmt, c, s)
-			monitor.PingMessageAll(ctx, ppfmt, c.Monitors, msg.MonitorMessage)
-			notifier.SendMessageAll(ctx, ppfmt, c.Notifiers, msg.NotifierMessage)
+			c.Monitor.Ping(ctx, ppfmt, msg.MonitorMessage)
+			c.Notifier.Send(ctx, ppfmt, msg.NotifierMessage)
 		}
 
 		if ctxWithSignals.Err() != nil {
@@ -148,9 +148,9 @@ func realMain() int { //nolint:funlen
 				cron.DescribeSchedule(c.UpdateCron),
 			)
 			stopUpdating(ctx, ppfmt, c, s)
-			monitor.ExitStatusAll(ctx, ppfmt, c.Monitors, 1, "No scheduled updates")
-			notifier.SendAll(ctx, ppfmt, c.Notifiers,
-				fmt.Sprintf(
+			c.Monitor.Ping(ctx, ppfmt, monitor.NewMessagef(false, "No scheduled updates"))
+			c.Notifier.Send(ctx, ppfmt,
+				notifier.NewMessagef(
 					"Cloudflare DDNS stopped because there are no scheduled updates in near future. "+
 						"Consider changing the value of UPDATE_CRON (%s).",
 					cron.DescribeSchedule(c.UpdateCron),
@@ -167,9 +167,9 @@ func realMain() int { //nolint:funlen
 		// Wait for the next signal or the alarm, whichever comes first
 		if sig.WaitForSignalsUntil(ppfmt, next) {
 			stopUpdating(ctx, ppfmt, c, s)
-			monitor.ExitStatusAll(ctx, ppfmt, c.Monitors, 0, "Stopped")
+			c.Monitor.Exit(ctx, ppfmt, "Stopped")
 			if c.UpdateCron != nil {
-				notifier.SendAll(ctx, ppfmt, c.Notifiers, "Stopped running Cloudflare DDNS.")
+				c.Notifier.Send(ctx, ppfmt, notifier.NewMessagef("Stopped running Cloudflare DDNS."))
 			}
 			ppfmt.Infof(pp.EmojiBye, "Bye!")
 			return 0

go.mod

@@ -12,6 +12,7 @@ require (
 	github.com/stretchr/testify v1.9.0
 	go.uber.org/mock v0.4.0
 	golang.org/x/net v0.28.0
+	golang.org/x/text v0.17.0
 )
 
 require (
@@ -24,7 +25,6 @@ require (
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	golang.org/x/sync v0.8.0 // indirect
 	golang.org/x/sys v0.23.0 // indirect
-	golang.org/x/text v0.17.0 // indirect
 	golang.org/x/time v0.5.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

internal/config/config.go

@@ -31,8 +31,8 @@ type Config struct {
 	WAFListDescription string
 	DetectionTimeout   time.Duration
 	UpdateTimeout      time.Duration
-	Monitors           []monitor.Monitor
-	Notifiers          []notifier.Notifier
+	Monitor            monitor.Monitor
+	Notifier           notifier.Notifier
 }
 
 // Default gives the default configuration.
@@ -59,7 +59,7 @@ func Default() *Config {
 		WAFListDescription: "",
 		DetectionTimeout:   time.Second * 5,  //nolint:mnd
 		UpdateTimeout:      time.Second * 30, //nolint:mnd
-		Monitors:           nil,
-		Notifiers:          nil,
+		Monitor:            nil,
+		Notifier:           nil,
 	}
 }

internal/config/config_print.go

@@ -10,8 +10,6 @@ import (
 	"github.com/favonia/cloudflare-ddns/internal/cron"
 	"github.com/favonia/cloudflare-ddns/internal/domain"
 	"github.com/favonia/cloudflare-ddns/internal/ipnet"
-	"github.com/favonia/cloudflare-ddns/internal/monitor"
-	"github.com/favonia/cloudflare-ddns/internal/notifier"
 	"github.com/favonia/cloudflare-ddns/internal/pp"
 	"github.com/favonia/cloudflare-ddns/internal/provider"
 )
@@ -88,17 +86,17 @@ func (c *Config) Print(ppfmt pp.PP) {
 	item("IP detection:", "%v", c.DetectionTimeout)
 	item("Record/list updating:", "%v", c.UpdateTimeout)
 
-	if len(c.Monitors) > 0 {
+	if c.Monitor != nil {
 		section("Monitors:")
-		monitor.DescribeAll(func(service, params string) {
-			item(service+":", "%s", params)
-		}, c.Monitors)
+		for name, params := range c.Monitor.Describe {
+			item(name+":", "%s", params)
+		}
 	}
 
-	if len(c.Notifiers) > 0 {
+	if c.Notifier != nil {
 		section("Notification services (via shoutrrr):")
-		notifier.DescribeAll(func(service, params string) {
-			item(service+":", "%s", params)
-		}, c.Notifiers)
+		for name, params := range c.Notifier.Describe {
+			item(name+":", "%s", params)
+		}
 	}
 }

internal/config/config_print_test.go

@@ -9,8 +9,6 @@ import (
 	"github.com/favonia/cloudflare-ddns/internal/domain"
 	"github.com/favonia/cloudflare-ddns/internal/ipnet"
 	"github.com/favonia/cloudflare-ddns/internal/mocks"
-	"github.com/favonia/cloudflare-ddns/internal/monitor"
-	"github.com/favonia/cloudflare-ddns/internal/notifier"
 	"github.com/favonia/cloudflare-ddns/internal/pp"
 )
 
@@ -114,17 +112,17 @@ func TestPrintValues(t *testing.T) {
 
 	m := mocks.NewMockMonitor(mockCtrl)
 	m.EXPECT().Describe(gomock.Any()).
-		DoAndReturn(func(f func(string, string)) {
+		DoAndReturn(func(f func(string, string) bool) {
 			f("Meow", "purrrr")
 		}).AnyTimes()
-	c.Monitors = []monitor.Monitor{m}
+	c.Monitor = m
 
 	n := mocks.NewMockNotifier(mockCtrl)
 	n.EXPECT().Describe(gomock.Any()).
-		DoAndReturn(func(f func(string, string)) {
+		DoAndReturn(func(f func(string, string) bool) {
 			f("Snake", "hissss")
 		}).AnyTimes()
-	c.Notifiers = []notifier.Notifier{n}
+	c.Notifier = n
 
 	c.Print(mockPP)
 }

internal/config/config_read.go

@@ -34,9 +34,9 @@ func (c *Config) ReadEnv(ppfmt pp.PP) bool {
 		!ReadString(ppfmt, "WAF_LIST_DESCRIPTION", &c.WAFListDescription) ||
 		!ReadNonnegDuration(ppfmt, "DETECTION_TIMEOUT", &c.DetectionTimeout) ||
 		!ReadNonnegDuration(ppfmt, "UPDATE_TIMEOUT", &c.UpdateTimeout) ||
-		!ReadAndAppendHealthchecksURL(ppfmt, "HEALTHCHECKS", &c.Monitors) ||
-		!ReadAndAppendUptimeKumaURL(ppfmt, "UPTIMEKUMA", &c.Monitors) ||
-		!ReadAndAppendShoutrrrURL(ppfmt, "SHOUTRRR", &c.Notifiers) {
+		!ReadAndAppendHealthchecksURL(ppfmt, "HEALTHCHECKS", &c.Monitor) ||
+		!ReadAndAppendUptimeKumaURL(ppfmt, "UPTIMEKUMA", &c.Monitor) ||
+		!ReadAndAppendShoutrrrURL(ppfmt, "SHOUTRRR", &c.Notifier) {
 		return false
 	}
 

internal/config/env_monitor.go

@@ -6,7 +6,7 @@ import (
 )
 
 // ReadAndAppendHealthchecksURL reads the base URL of a Healthchecks endpoint.
-func ReadAndAppendHealthchecksURL(ppfmt pp.PP, key string, field *[]monitor.Monitor) bool {
+func ReadAndAppendHealthchecksURL(ppfmt pp.PP, key string, field *monitor.Monitor) bool {
 	val := Getenv(key)
 
 	if val == "" {
@@ -19,12 +19,12 @@ func ReadAndAppendHealthchecksURL(ppfmt pp.PP, key string, field *[]monitor.Moni
 	}
 
 	// Append the new monitor to the existing list
-	*field = append(*field, h)
+	*field = monitor.NewComposed(*field, h)
 	return true
 }
 
 // ReadAndAppendUptimeKumaURL reads the URL of a Push Monitor of an Uptime Kuma server.
-func ReadAndAppendUptimeKumaURL(ppfmt pp.PP, key string, field *[]monitor.Monitor) bool {
+func ReadAndAppendUptimeKumaURL(ppfmt pp.PP, key string, field *monitor.Monitor) bool {
 	val := Getenv(key)
 
 	if val == "" {
@@ -37,6 +37,6 @@ func ReadAndAppendUptimeKumaURL(ppfmt pp.PP, key string, field *[]monitor.Monito
 	}
 
 	// Append the new monitor to the existing list
-	*field = append(*field, h)
+	*field = monitor.NewComposed(*field, h)
 	return true
 }

internal/config/env_monitor_test.go

@@ -21,8 +21,8 @@ func TestReadAndAppendHealthchecksURL(t *testing.T) {
 	for name, tc := range map[string]struct {
 		set           bool
 		val           string
-		oldField      []mon
-		newField      []mon
+		oldField      mon
+		newField      mon
 		ok            bool
 		prepareMockPP func(*mocks.MockPP)
 	}{
@@ -35,30 +35,30 @@ func TestReadAndAppendHealthchecksURL(t *testing.T) {
 		"example": {
 			true, "https://hi.org/1234",
 			nil,
-			[]mon{monitor.Healthchecks{
+			monitor.NewComposed(monitor.Healthchecks{
 				BaseURL: urlMustParse(t, "https://hi.org/1234"),
 				Timeout: monitor.HealthchecksDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
 		"password": {
 			true, "https://me:pass@hi.org/1234",
 			nil,
-			[]mon{monitor.Healthchecks{
+			monitor.NewComposed(monitor.Healthchecks{
 				BaseURL: urlMustParse(t, "https://me:pass@hi.org/1234"),
 				Timeout: monitor.HealthchecksDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
 		"fragment": {
 			true, "https://hi.org/1234#fragment",
 			nil,
-			[]mon{monitor.Healthchecks{
+			monitor.NewComposed(monitor.Healthchecks{
 				BaseURL: urlMustParse(t, "https://hi.org/1234#fragment"),
 				Timeout: monitor.HealthchecksDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
@@ -118,8 +118,8 @@ func TestReadAndAppendUptimeKumaURL(t *testing.T) {
 	for name, tc := range map[string]struct {
 		set           bool
 		val           string
-		oldField      []mon
-		newField      []mon
+		oldField      mon
+		newField      mon
 		ok            bool
 		prepareMockPP func(*mocks.MockPP)
 	}{
@@ -132,40 +132,40 @@ func TestReadAndAppendUptimeKumaURL(t *testing.T) {
 		"example": {
 			true, "https://hi.org/1234",
 			nil,
-			[]mon{monitor.UptimeKuma{
+			monitor.NewComposed(monitor.UptimeKuma{
 				BaseURL: urlMustParse(t, "https://hi.org/1234"),
 				Timeout: monitor.UptimeKumaDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
 		"password": {
 			true, "https://me:pass@hi.org/1234",
 			nil,
-			[]mon{monitor.UptimeKuma{
+			monitor.NewComposed(monitor.UptimeKuma{
 				BaseURL: urlMustParse(t, "https://me:pass@hi.org/1234"),
 				Timeout: monitor.UptimeKumaDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
 		"fragment": {
 			true, "https://hi.org/1234#fragment",
 			nil,
-			[]mon{monitor.UptimeKuma{
+			monitor.NewComposed(monitor.UptimeKuma{
 				BaseURL: urlMustParse(t, "https://hi.org/1234#fragment"),
 				Timeout: monitor.UptimeKumaDefaultTimeout,
-			}},
+			}),
 			true,
 			nil,
 		},
 		"query": {
 			true, "https://hi.org/1234?hello=123",
 			nil,
-			[]mon{monitor.UptimeKuma{
+			monitor.NewComposed(monitor.UptimeKuma{
 				BaseURL: urlMustParse(t, "https://hi.org/1234"),
 				Timeout: monitor.UptimeKumaDefaultTimeout,
-			}},
+			}),
 			true,
 			func(m *mocks.MockPP) {
 				m.EXPECT().Noticef(pp.EmojiUserError,

internal/config/env_notifier.go

@@ -6,7 +6,7 @@ import (
 )
 
 // ReadAndAppendShoutrrrURL reads the URLs separated by the newline.
-func ReadAndAppendShoutrrrURL(ppfmt pp.PP, key string, field *[]notifier.Notifier) bool {
+func ReadAndAppendShoutrrrURL(ppfmt pp.PP, key string, field *notifier.Notifier) bool {
 	vals := GetenvAsList(key, "\n")
 	if len(vals) == 0 {
 		return true
@@ -18,6 +18,6 @@ func ReadAndAppendShoutrrrURL(ppfmt pp.PP, key string, field *[]notifier.Notifie
 	}
 
 	// Append the new monitor to the existing list
-	*field = append(*field, s)
+	*field = s
 	return true
 }