[feature] Change instance-stats-randomize to instance-stats-mode with multiple options; implement nodeinfo 2.1 (#3734)

* [feature] Change `instance-stats-randomize` to `instance-stats-mode` with multiple options; implement nodeinfo 2.1

* swaggalaggadingdong

internal/config/config.go

@@ -90,7 +90,7 @@ type Configuration struct {
 	InstanceLanguages                 language.Languages `name:"instance-languages" usage:"BCP47 language tags for the instance. Used to indicate the preferred languages of instance residents (in order from most-preferred to least-preferred)."`
 	InstanceSubscriptionsProcessFrom  string             `name:"instance-subscriptions-process-from" usage:"Time of day from which to start running instance subscriptions processing jobs. Should be in the format 'hh:mm:ss', eg., '15:04:05'."`
 	InstanceSubscriptionsProcessEvery time.Duration      `name:"instance-subscriptions-process-every" usage:"Period to elapse between instance subscriptions processing jobs, starting from instance-subscriptions-process-from."`
-	InstanceStatsRandomize            bool               `name:"instance-stats-randomize" usage:"Set to true to randomize the stats served at api/v1/instance and api/v2/instance endpoints. Home page stats remain unchanged."`
+	InstanceStatsMode                 string             `name:"instance-stats-mode" usage:"Allows you to customize the way stats are served to crawlers: one of '', 'serve', 'zero', 'baffle'. Home page stats remain unchanged."`
 
 	AccountsRegistrationOpen bool `name:"accounts-registration-open" usage:"Allow anyone to submit an account signup request. If false, server will be invite-only."`
 	AccountsReasonRequired   bool `name:"accounts-reason-required" usage:"Do new account signups require a reason to be submitted on registration?"`

internal/config/const.go

@@ -17,16 +17,28 @@
 
 package config
 
+// Instance federation mode determines how this
+// instance federates with others (if at all).
 const (
-	// Instance federation mode determines how this
-	// instance federates with others (if at all).
 	InstanceFederationModeBlocklist = "blocklist"
 	InstanceFederationModeAllowlist = "allowlist"
 	InstanceFederationModeDefault   = InstanceFederationModeBlocklist
+)
 
-	// Request header filter mode determines how
-	// this instance will perform request filtering.
+// Request header filter mode determines how
+// this instance will perform request filtering.
+const (
 	RequestHeaderFilterModeAllow    = "allow"
 	RequestHeaderFilterModeBlock    = "block"
 	RequestHeaderFilterModeDisabled = ""
 )
+
+// Instance stats mode determines if and how
+// stats about the instance are served at
+// nodeinfo and api/v1|v2/instance endpoints.
+const (
+	InstanceStatsModeDefault = ""
+	InstanceStatsModeServe   = "serve"
+	InstanceStatsModeZero    = "zero"
+	InstanceStatsModeBaffle  = "baffle"
+)

internal/config/flags.go

@@ -92,7 +92,7 @@ func (s *ConfigState) AddServerFlags(cmd *cobra.Command) {
 		cmd.Flags().StringSlice(InstanceLanguagesFlag(), cfg.InstanceLanguages.TagStrs(), fieldtag("InstanceLanguages", "usage"))
 		cmd.Flags().String(InstanceSubscriptionsProcessFromFlag(), cfg.InstanceSubscriptionsProcessFrom, fieldtag("InstanceSubscriptionsProcessFrom", "usage"))
 		cmd.Flags().Duration(InstanceSubscriptionsProcessEveryFlag(), cfg.InstanceSubscriptionsProcessEvery, fieldtag("InstanceSubscriptionsProcessEvery", "usage"))
-		cmd.Flags().Bool(InstanceStatsRandomizeFlag(), cfg.InstanceStatsRandomize, fieldtag("InstanceStatsRandomize", "usage"))
+		cmd.Flags().String(InstanceStatsModeFlag(), cfg.InstanceStatsMode, fieldtag("InstanceStatsMode", "usage"))
 
 		// Accounts
 		cmd.Flags().Bool(AccountsRegistrationOpenFlag(), cfg.AccountsRegistrationOpen, fieldtag("AccountsRegistrationOpen", "usage"))

internal/config/helpers.gen.go

@@ -1057,30 +1057,30 @@ func SetInstanceSubscriptionsProcessEvery(v time.Duration) {
 	global.SetInstanceSubscriptionsProcessEvery(v)
 }
 
-// GetInstanceStatsRandomize safely fetches the Configuration value for state's 'InstanceStatsRandomize' field
-func (st *ConfigState) GetInstanceStatsRandomize() (v bool) {
+// GetInstanceStatsMode safely fetches the Configuration value for state's 'InstanceStatsMode' field
+func (st *ConfigState) GetInstanceStatsMode() (v string) {
 	st.mutex.RLock()
-	v = st.config.InstanceStatsRandomize
+	v = st.config.InstanceStatsMode
 	st.mutex.RUnlock()
 	return
 }
 
-// SetInstanceStatsRandomize safely sets the Configuration value for state's 'InstanceStatsRandomize' field
-func (st *ConfigState) SetInstanceStatsRandomize(v bool) {
+// SetInstanceStatsMode safely sets the Configuration value for state's 'InstanceStatsMode' field
+func (st *ConfigState) SetInstanceStatsMode(v string) {
 	st.mutex.Lock()
 	defer st.mutex.Unlock()
-	st.config.InstanceStatsRandomize = v
+	st.config.InstanceStatsMode = v
 	st.reloadToViper()
 }
 
-// InstanceStatsRandomizeFlag returns the flag name for the 'InstanceStatsRandomize' field
-func InstanceStatsRandomizeFlag() string { return "instance-stats-randomize" }
+// InstanceStatsModeFlag returns the flag name for the 'InstanceStatsMode' field
+func InstanceStatsModeFlag() string { return "instance-stats-mode" }
 
-// GetInstanceStatsRandomize safely fetches the value for global configuration 'InstanceStatsRandomize' field
-func GetInstanceStatsRandomize() bool { return global.GetInstanceStatsRandomize() }
+// GetInstanceStatsMode safely fetches the value for global configuration 'InstanceStatsMode' field
+func GetInstanceStatsMode() string { return global.GetInstanceStatsMode() }
 
-// SetInstanceStatsRandomize safely sets the value for global configuration 'InstanceStatsRandomize' field
-func SetInstanceStatsRandomize(v bool) { global.SetInstanceStatsRandomize(v) }
+// SetInstanceStatsMode safely sets the value for global configuration 'InstanceStatsMode' field
+func SetInstanceStatsMode(v string) { global.SetInstanceStatsMode(v) }
 
 // GetAccountsRegistrationOpen safely fetches the Configuration value for state's 'AccountsRegistrationOpen' field
 func (st *ConfigState) GetAccountsRegistrationOpen() (v bool) {

internal/config/validate.go

@@ -115,6 +115,19 @@ func Validate() error {
 		SetInstanceLanguages(parsedLangs)
 	}
 
+	// `instance-stats-mode` should be
+	// "", "zero", "serve", or "baffle"
+	switch statsMode := GetInstanceStatsMode(); statsMode {
+	case InstanceStatsModeDefault, InstanceStatsModeZero, InstanceStatsModeServe, InstanceStatsModeBaffle:
+		// No problem.
+
+	default:
+		errf(
+			"%s must be set to empty string, zero, serve, or baffle, provided value was %s",
+			InstanceFederationModeFlag(), statsMode,
+		)
+	}
+
 	// `web-assets-base-dir`.
 	webAssetsBaseDir := GetWebAssetBaseDir()
 	if webAssetsBaseDir == "" {