feat(config): add SCHEDULER_ROUND_ROBIN_MAX_INTERVAL option

Add option to cap maximum refresh interval when RSS TTL, Retry-After, Cache-Control, or Expires headers specify excessively high values.

internal/config/config_test.go

@@ -1028,6 +1028,41 @@ func TestSchedulerRoundRobin(t *testing.T) {
 	}
 }
 
+func TestDefaultSchedulerRoundRobinMaxIntervalValue(t *testing.T) {
+	os.Clearenv()
+
+	parser := NewParser()
+	opts, err := parser.ParseEnvironmentVariables()
+	if err != nil {
+		t.Fatalf(`Parsing failure: %v`, err)
+	}
+
+	expected := defaultSchedulerRoundRobinMaxInterval
+	result := opts.SchedulerRoundRobinMaxInterval()
+
+	if result != expected {
+		t.Fatalf(`Unexpected SCHEDULER_ROUND_ROBIN_MAX_INTERVAL value, got %v instead of %v`, result, expected)
+	}
+}
+
+func TestSchedulerRoundRobinMaxInterval(t *testing.T) {
+	os.Clearenv()
+	os.Setenv("SCHEDULER_ROUND_ROBIN_MAX_INTERVAL", "150")
+
+	parser := NewParser()
+	opts, err := parser.ParseEnvironmentVariables()
+	if err != nil {
+		t.Fatalf(`Parsing failure: %v`, err)
+	}
+
+	expected := 150
+	result := opts.SchedulerRoundRobinMaxInterval()
+
+	if result != expected {
+		t.Fatalf(`Unexpected SCHEDULER_ROUND_ROBIN_MAX_INTERVAL value, got %v instead of %v`, result, expected)
+	}
+}
+
 func TestPollingParsingErrorLimit(t *testing.T) {
 	os.Clearenv()
 	os.Setenv("POLLING_PARSING_ERROR_LIMIT", "100")

internal/config/options.go

@@ -37,6 +37,7 @@ const (
 	defaultSchedulerEntryFrequencyMaxInterval = 24 * 60
 	defaultSchedulerEntryFrequencyFactor      = 1
 	defaultSchedulerRoundRobinMinInterval     = 60
+	defaultSchedulerRoundRobinMaxInterval     = 1440
 	defaultPollingParsingErrorLimit           = 3
 	defaultRunMigrations                      = false
 	defaultDatabaseURL                        = "user=postgres password=postgres dbname=miniflux2 sslmode=disable"
@@ -137,6 +138,7 @@ type Options struct {
 	schedulerEntryFrequencyMaxInterval int
 	schedulerEntryFrequencyFactor      int
 	schedulerRoundRobinMinInterval     int
+	schedulerRoundRobinMaxInterval     int
 	pollingParsingErrorLimit           int
 	workerPoolSize                     int
 	createAdmin                        bool
@@ -220,6 +222,7 @@ func NewOptions() *Options {
 		schedulerEntryFrequencyMaxInterval: defaultSchedulerEntryFrequencyMaxInterval,
 		schedulerEntryFrequencyFactor:      defaultSchedulerEntryFrequencyFactor,
 		schedulerRoundRobinMinInterval:     defaultSchedulerRoundRobinMinInterval,
+		schedulerRoundRobinMaxInterval:     defaultSchedulerRoundRobinMaxInterval,
 		pollingParsingErrorLimit:           defaultPollingParsingErrorLimit,
 		workerPoolSize:                     defaultWorkerPoolSize,
 		createAdmin:                        defaultCreateAdmin,
@@ -433,6 +436,10 @@ func (o *Options) SchedulerRoundRobinMinInterval() int {
 	return o.schedulerRoundRobinMinInterval
 }
 
+func (o *Options) SchedulerRoundRobinMaxInterval() int {
+	return o.schedulerRoundRobinMaxInterval
+}
+
 // PollingParsingErrorLimit returns the limit of errors when to stop polling.
 func (o *Options) PollingParsingErrorLimit() int {
 	return o.pollingParsingErrorLimit
@@ -778,6 +785,7 @@ func (o *Options) SortedOptions(redactSecret bool) []*Option {
 		"SCHEDULER_ENTRY_FREQUENCY_MIN_INTERVAL": o.schedulerEntryFrequencyMinInterval,
 		"SCHEDULER_ENTRY_FREQUENCY_FACTOR":       o.schedulerEntryFrequencyFactor,
 		"SCHEDULER_ROUND_ROBIN_MIN_INTERVAL":     o.schedulerRoundRobinMinInterval,
+		"SCHEDULER_ROUND_ROBIN_MAX_INTERVAL":     o.schedulerRoundRobinMaxInterval,
 		"SCHEDULER_SERVICE":                      o.schedulerService,
 		"SERVER_TIMING_HEADER":                   o.serverTimingHeader,
 		"WATCHDOG":                               o.watchdog,

internal/config/parser.go

@@ -160,6 +160,8 @@ func (p *Parser) parseLines(lines []string) (err error) {
 			p.opts.schedulerEntryFrequencyFactor = parseInt(value, defaultSchedulerEntryFrequencyFactor)
 		case "SCHEDULER_ROUND_ROBIN_MIN_INTERVAL":
 			p.opts.schedulerRoundRobinMinInterval = parseInt(value, defaultSchedulerRoundRobinMinInterval)
+		case "SCHEDULER_ROUND_ROBIN_MAX_INTERVAL":
+			p.opts.schedulerRoundRobinMaxInterval = parseInt(value, defaultSchedulerRoundRobinMaxInterval)
 		case "POLLING_PARSING_ERROR_LIMIT":
 			p.opts.pollingParsingErrorLimit = parseInt(value, defaultPollingParsingErrorLimit)
 		case "PROXY_IMAGES":