add unplug command

docs/changelog.txt

@@ -2,6 +2,8 @@ changelog
 
 -- next
 
++ Add unplug command for servers that have dropped off the net.
+
 + Add notes field to honkers to document their downfall.
 
 + Add notes field to filters for record keeping.

docs/honk.8

@@ -133,6 +133,12 @@ file which is important to backup and restore.
 The current version of the honk binary may be printed with the
 .Ic version
 command.
+.Ss unplug
+Sometimes servers simply disappear, resulting in many errors trying to deliver
+undeliverable messages.
+Running
+.Ic unplug Ar hostname
+will delete all subscriptions and pending deliveries.
 .Ss Security
 .Nm
 is not currently hardened against SSRF, server side request forgery.

honk.go

@@ -210,6 +210,13 @@ var loginMsg template.HTML
 func ElaborateUnitTests() {
 }
 
+func unplugserver(hostname string) {
+	db := opendatabase()
+	xid := fmt.Sprintf("%%https://%s/%%", hostname)
+	db.Exec("delete from honkers where xid like ? and flavor = 'dub'", xid)
+	db.Exec("delete from doovers where rcpt like ?", xid)
+}
+
 func main() {
 	flag.StringVar(&dataDir, "datadir", dataDir, "data directory")
 	flag.StringVar(&viewDir, "viewdir", viewDir, "view directory")
@@ -271,6 +278,13 @@ func main() {
 			arg = args[1]
 		}
 		cleanupdb(arg)
+	case "unplug":
+		if len(args) < 2 {
+			fmt.Printf("usage: honk unplug servername\n")
+			return
+		}
+		name := args[1]
+		unplugserver(name)
 	case "ping":
 		if len(args) < 3 {
 			fmt.Printf("usage: honk ping from to\n")