Gracefully start and exit the database

src/DittoExit.ts

@@ -0,0 +1,37 @@
+import { Stickynotes } from '@soapbox/stickynotes';
+
+/**
+ * Add cleanup tasks to this module,
+ * then they will automatically be called (and the program exited) after SIGINT.
+ */
+export class DittoExit {
+  private static tasks: Array<() => Promise<unknown>> = [];
+  private static console = new Stickynotes('ditto:exit');
+
+  static {
+    Deno.addSignalListener('SIGINT', () => this.finish('SIGINT'));
+    Deno.addSignalListener('SIGTERM', () => this.finish('SIGTERM'));
+    Deno.addSignalListener('SIGHUP', () => this.finish('SIGHUP'));
+    Deno.addSignalListener('SIGQUIT', () => this.finish('SIGQUIT'));
+    Deno.addSignalListener('SIGABRT', () => this.finish('SIGABRT'));
+  }
+
+  static add(task: () => Promise<unknown>): void {
+    this.tasks.push(task);
+    this.console.debug(`Added cleanup task #${this.tasks.length}`);
+  }
+
+  private static async cleanup(): Promise<void> {
+    this.console.debug(`Running ${this.tasks.length} cleanup tasks...`);
+    await Promise.allSettled(
+      this.tasks.map((task) => task()),
+    );
+  }
+
+  private static async finish(signal: Deno.Signal): Promise<void> {
+    this.console.debug(signal);
+    await this.cleanup();
+    this.console.debug('Exiting gracefully.');
+    Deno.exit(0);
+  }
+}

src/db/DittoDatabase.ts

@@ -6,6 +6,7 @@ export interface DittoDatabase {
   readonly kysely: Kysely<DittoTables>;
   readonly poolSize: number;
   readonly availableConnections: number;
+  readonly waitReady: Promise<void>;
 }
 
 export interface DittoDatabaseOpts {

src/db/adapters/DittoPglite.ts

@@ -8,9 +8,11 @@ import { KyselyLogger } from '@/db/KyselyLogger.ts';
 
 export class DittoPglite {
   static create(databaseUrl: string): DittoDatabase {
+    const pglite = new PGlite(databaseUrl);
+
     const kysely = new Kysely<DittoTables>({
       dialect: new PgliteDialect({
-        database: new PGlite(databaseUrl),
+        database: pglite,
       }),
       log: KyselyLogger,
     });
@@ -19,6 +21,7 @@ export class DittoPglite {
       kysely,
       poolSize: 1,
       availableConnections: 1,
+      waitReady: pglite.waitReady,
     };
   }
 }

src/db/adapters/DittoPostgres.ts

@@ -48,6 +48,7 @@ export class DittoPostgres {
       get availableConnections() {
         return pg.connections.idle;
       },
+      waitReady: Promise.resolve(),
     };
   }
 }

src/server.ts

@@ -5,5 +5,16 @@ import '@/sentry.ts';
 import '@/nostr-wasm.ts';
 import app from '@/app.ts';
 import { Conf } from '@/config.ts';
+import { DittoExit } from '@/DittoExit.ts';
 
-Deno.serve({ port: Conf.port }, app.fetch);
+const ac = new AbortController();
+// deno-lint-ignore require-await
+DittoExit.add(async () => ac.abort());
+
+Deno.serve(
+  {
+    port: Conf.port,
+    signal: ac.signal,
+  },
+  app.fetch,
+);

src/storages.ts

@@ -2,6 +2,7 @@
 import { Conf } from '@/config.ts';
 import { DittoDatabase } from '@/db/DittoDatabase.ts';
 import { DittoDB } from '@/db/DittoDB.ts';
+import { DittoExit } from '@/DittoExit.ts';
 import { AdminStore } from '@/storages/AdminStore.ts';
 import { EventsDB } from '@/storages/EventsDB.ts';
 import { SearchStore } from '@/storages/search-store.ts';
@@ -10,9 +11,11 @@ import { NPool, NRelay1 } from '@nostrify/nostrify';
 import { getRelays } from '@/utils/outbox.ts';
 import { seedZapSplits } from '@/utils/zap-split.ts';
 
+DittoExit.add(() => Storages.close());
+
 export class Storages {
   private static _db: Promise<EventsDB> | undefined;
-  private static _database: DittoDatabase | undefined;
+  private static _database: Promise<DittoDatabase> | undefined;
   private static _admin: Promise<AdminStore> | undefined;
   private static _client: Promise<NPool> | undefined;
   private static _pubsub: Promise<InternalRelay> | undefined;
@@ -20,8 +23,12 @@ export class Storages {
 
   public static async database(): Promise<DittoDatabase> {
     if (!this._database) {
-      this._database = DittoDB.create(Conf.databaseUrl, { poolSize: Conf.pg.poolSize });
-      await DittoDB.migrate(this._database.kysely);
+      this._database = (async () => {
+        const db = DittoDB.create(Conf.databaseUrl, { poolSize: Conf.pg.poolSize });
+        await db.waitReady;
+        await DittoDB.migrate(db.kysely);
+        return db;
+      })();
     }
     return this._database;
   }
@@ -35,7 +42,7 @@ export class Storages {
   public static async db(): Promise<EventsDB> {
     if (!this._db) {
       this._db = (async () => {
-        const { kysely } = await this.database();
+        const kysely = await this.kysely();
         const store = new EventsDB({ kysely, pubkey: Conf.pubkey, timeout: Conf.db.timeouts.default });
         await seedZapSplits(store);
         return store;
@@ -118,4 +125,12 @@ export class Storages {
     }
     return this._search;
   }
+
+  /** Close the database connection, if one has been opened. */
+  public static async close(): Promise<void> {
+    if (this._database) {
+      const { kysely } = await this._database;
+      await kysely.destroy();
+    }
+  }
 }