[feature] Public list of suspended domains (#1362)

* basic rendered domain blocklist (unauthenticated!)

* style basic domain block list

* better formatting for domain blocklist

* add opt-in config option for showing suspended domains

* format/linter

* re-use InstancePeersGet for web-accessible domain blocklist

* reword explanation, border styling

* always attach blocklist handler, update error message

* domain blocklist error message grammar

4 files changed, 28 insertions, 0 deletions

diff --git a/internal/config/config.go b/internal/config/config.go
index c28cfe419..472e7b93d 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -76,6 +76,7 @@ type Configuration struct {
 
 	InstanceExposePeers            bool `name:"instance-expose-peers" usage:"Allow unauthenticated users to query /api/v1/instance/peers?filter=open"`
 	InstanceExposeSuspended        bool `name:"instance-expose-suspended" usage:"Expose suspended instances via web UI, and allow unauthenticated users to query /api/v1/instance/peers?filter=suspended"`
+	InstanceExposeSuspendedWeb     bool `name:"instance-expose-suspended-web" usage:"Expose list of suspended instances as webpage on /about/suspended"`
 	InstanceExposePublicTimeline   bool `name:"instance-expose-public-timeline" usage:"Allow unauthenticated users to query /api/v1/timelines/public"`
 	InstanceDeliverToSharedInboxes bool `name:"instance-deliver-to-shared-inboxes" usage:"Deliver federated messages to shared inboxes, if they're available."`
 
diff --git a/internal/config/defaults.go b/internal/config/defaults.go
index 3cd1a3ed3..ecd32be2f 100644
--- a/internal/config/defaults.go
+++ b/internal/config/defaults.go
@@ -58,6 +58,7 @@ var Defaults = Configuration{
 
 	InstanceExposePeers:            false,
 	InstanceExposeSuspended:        false,
+	InstanceExposeSuspendedWeb:     false,
 	InstanceDeliverToSharedInboxes: true,
 
 	AccountsRegistrationOpen: true,
diff --git a/internal/config/flags.go b/internal/config/flags.go
index a0fde3eed..a21f17f53 100644
--- a/internal/config/flags.go
+++ b/internal/config/flags.go
@@ -78,6 +78,7 @@ func (s *ConfigState) AddServerFlags(cmd *cobra.Command) {
 		// Instance
 		cmd.Flags().Bool(InstanceExposePeersFlag(), cfg.InstanceExposePeers, fieldtag("InstanceExposePeers", "usage"))
 		cmd.Flags().Bool(InstanceExposeSuspendedFlag(), cfg.InstanceExposeSuspended, fieldtag("InstanceExposeSuspended", "usage"))
+		cmd.Flags().Bool(InstanceExposeSuspendedWebFlag(), cfg.InstanceExposeSuspendedWeb, fieldtag("InstanceExposeSuspendedWeb", "usage"))
 		cmd.Flags().Bool(InstanceDeliverToSharedInboxesFlag(), cfg.InstanceDeliverToSharedInboxes, fieldtag("InstanceDeliverToSharedInboxes", "usage"))
 
 		// Accounts
diff --git a/internal/config/helpers.gen.go b/internal/config/helpers.gen.go
index 1da2ff42c..3560c566a 100644
--- a/internal/config/helpers.gen.go
+++ b/internal/config/helpers.gen.go
@@ -724,6 +724,31 @@ func GetInstanceExposeSuspended() bool { return global.GetInstanceExposeSuspende
 // SetInstanceExposeSuspended safely sets the value for global configuration 'InstanceExposeSuspended' field
 func SetInstanceExposeSuspended(v bool) { global.SetInstanceExposeSuspended(v) }
 
+// GetInstanceExposeSuspendedWeb safely fetches the Configuration value for state's 'InstanceExposeSuspendedWeb' field
+func (st *ConfigState) GetInstanceExposeSuspendedWeb() (v bool) {
+	st.mutex.Lock()
+	v = st.config.InstanceExposeSuspendedWeb
+	st.mutex.Unlock()
+	return
+}
+
+// SetInstanceExposeSuspendedWeb safely sets the Configuration value for state's 'InstanceExposeSuspendedWeb' field
+func (st *ConfigState) SetInstanceExposeSuspendedWeb(v bool) {
+	st.mutex.Lock()
+	defer st.mutex.Unlock()
+	st.config.InstanceExposeSuspendedWeb = v
+	st.reloadToViper()
+}
+
+// InstanceExposeSuspendedWebFlag returns the flag name for the 'InstanceExposeSuspendedWeb' field
+func InstanceExposeSuspendedWebFlag() string { return "instance-expose-suspended-web" }
+
+// GetInstanceExposeSuspendedWeb safely fetches the value for global configuration 'InstanceExposeSuspendedWeb' field
+func GetInstanceExposeSuspendedWeb() bool { return global.GetInstanceExposeSuspendedWeb() }
+
+// SetInstanceExposeSuspendedWeb safely sets the value for global configuration 'InstanceExposeSuspendedWeb' field
+func SetInstanceExposeSuspendedWeb(v bool) { global.SetInstanceExposeSuspendedWeb(v) }
+
 // GetInstanceExposePublicTimeline safely fetches the Configuration value for state's 'InstanceExposePublicTimeline' field
 func (st *ConfigState) GetInstanceExposePublicTimeline() (v bool) {
 	st.mutex.Lock()