feat: do a little better at cleanup

cmd/mostliked/main.go

···
 package main
 
 import (
+	"database/sql"
 	"log"
+	"os"
+	"os/signal"
+	"syscall"
 
 	"github.com/edavis/bsky-feeds/pkg/mostliked"
 	"github.com/gorilla/websocket"
+	_ "github.com/mattn/go-sqlite3"
 )
 
 func main() {
···
 		log.Fatal("websocket connection error:", err)
 	}
 	defer conn.Close()
+
+	dbCnx, err := sql.Open("sqlite3", "data/mostliked.db?_journal=WAL&_fk=on")
+	if err != nil {
+		log.Fatal("error opening db")
+	}
+	defer dbCnx.Close()
 
 	jetstreamEvents := make(chan []byte)
-	go mostliked.Handler(jetstreamEvents)
+	go mostliked.Handler(jetstreamEvents, dbCnx)
+
+	signalChan := make(chan os.Signal, 1)
+	cleanupDone := make(chan struct{})
+	signal.Notify(signalChan, os.Interrupt, syscall.SIGINT, syscall.SIGTERM)
+
+	go func(conn *websocket.Conn, dbCnx *sql.DB, jetstreamEvents chan []byte) {
+		<-signalChan
+		log.Println("shutting down...")
+		close(jetstreamEvents)
+		dbCnx.Close()
+		conn.Close()
+		close(cleanupDone)
+	}(conn, dbCnx, jetstreamEvents)
 
 	log.Println("starting up")
-	for {
-		_, message, err := conn.ReadMessage()
-		if err != nil {
-			log.Println("error reading from websocket:", err)
-			break
+	go func(conn *websocket.Conn) {
+		for {
+			_, message, err := conn.ReadMessage()
+			if err != nil {
+				log.Println("error reading from websocket:", err)
+				break
+			}
+			jetstreamEvents <- message
 		}
-		jetstreamEvents <- message
-	}
+	}(conn)
+
+	<-cleanupDone
 }

pkg/mostliked/handler.go

···
 	return ""
 }
 
-func Handler(events <-chan []byte) {
+func Handler(events <-chan []byte, dbCnx *sql.DB) {
 	ctx := context.Background()
 
-	dbCnx, err := sql.Open("sqlite3", "data/mostliked.db?_journal=WAL&_fk=on")
-	if err != nil {
-		log.Fatal("error opening db")
-	}
 	if _, err := dbCnx.ExecContext(ctx, ddl); err != nil {
 		log.Fatal("couldn't create tables")
 	}
-	defer dbCnx.Close()
-
 	queries := db.New(dbCnx)
 
 	drafts := ccache.New(ccache.Configure[DraftPost]().MaxSize(50_000).GetsPerPromote(1))