Bsky short link service (#4542)

* bskylink: scaffold service w/ initial config and schema

* bskylink: implement link creation and redirects

* bskylink: tidy

* bskylink: tests

* bskylink: tidy, add error handler

* bskylink: add dockerfile

* bskylink: add build

* bskylink: fix some express plumbing

* bskyweb: proxy fallthrough routes to link service redirects

* bskyweb: build w/ link proxy

* Add AASA to bskylink (#4588)

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Co-authored-by: Hailey <me@haileyok.com>

bskylink/src/index.ts

@@ -0,0 +1,45 @@
+import events from 'node:events'
+import http from 'node:http'
+
+import cors from 'cors'
+import express from 'express'
+import {createHttpTerminator, HttpTerminator} from 'http-terminator'
+
+import {Config} from './config.js'
+import {AppContext} from './context.js'
+import {default as routes, errorHandler} from './routes/index.js'
+
+export * from './config.js'
+export * from './db/index.js'
+export * from './logger.js'
+
+export class LinkService {
+  public server?: http.Server
+  private terminator?: HttpTerminator
+
+  constructor(public app: express.Application, public ctx: AppContext) {}
+
+  static async create(cfg: Config): Promise<LinkService> {
+    let app = express()
+    app.use(cors())
+
+    const ctx = await AppContext.fromConfig(cfg)
+    app = routes(ctx, app)
+    app.use(errorHandler)
+
+    return new LinkService(app, ctx)
+  }
+
+  async start() {
+    this.server = this.app.listen(this.ctx.cfg.service.port)
+    this.server.keepAliveTimeout = 90000
+    this.terminator = createHttpTerminator({server: this.server})
+    await events.once(this.server, 'listening')
+  }
+
+  async destroy() {
+    this.ctx.abortController.abort()
+    await this.terminator?.terminate()
+    await this.ctx.db.close()
+  }
+}