Bsky link card service (#4547)

* setup bskycard

* quick proof of concept for png card generation

* bskycard: use jsx

* bskycard: 3x5 profile layout

* bskycard: add butterfly overlay

* bskycard: tidy

* bskycard: separate and reorganize

* bskycard: tidy

* bskycard: tidy

* bskycard: tidy

* bskycard: poc of transparent overlay and box shadow

* bskycard: reorg impl into src/ directory

* bskycard: use more standard app structure

* bskycard: setup dockerfile, fix build

* bskycard: support for x-origin-verify

* bskycard: card layout, filter images based on labels

* bskycard: tidy

* bskycard: support cluster mode

* bskycard: handle error fetching starter pack info

* bskycard: tidy

* bskycard: fix leak on failed image fetch

* bskycard: build workflow

* bskyogcard: rename from bskycard

* bskyogcard: fix some express plumbing

* bskyogcard: add cdn tags, tidy

1 files changed, 48 insertions, 0 deletions

diff --git a/bskyogcard/src/bin.ts b/bskyogcard/src/bin.ts
new file mode 100644
index 000000000..ff550809d
--- /dev/null
+++ b/bskyogcard/src/bin.ts
@@ -0,0 +1,48 @@
+import cluster, {Worker} from 'node:cluster'
+
+import {envInt} from '@atproto/common'
+
+import {CardService, envToCfg, httpLogger, readEnv} from './index.js'
+
+async function main() {
+  const env = readEnv()
+  const cfg = envToCfg(env)
+  const card = await CardService.create(cfg)
+  await card.start()
+  httpLogger.info('card service is running')
+  process.on('SIGTERM', async () => {
+    httpLogger.info('card service is stopping')
+    await card.destroy()
+    httpLogger.info('card service is stopped')
+    if (cluster.isWorker) process.exit(0)
+  })
+}
+
+const workerCount = envInt('CARD_CLUSTER_WORKER_COUNT')
+
+if (workerCount) {
+  if (cluster.isPrimary) {
+    httpLogger.info(`primary ${process.pid} is running`)
+    const workers = new Set<Worker>()
+    for (let i = 0; i < workerCount; ++i) {
+      workers.add(cluster.fork())
+    }
+    let teardown = false
+    cluster.on('exit', worker => {
+      workers.delete(worker)
+      if (!teardown) {
+        workers.add(cluster.fork()) // restart on crash
+      }
+    })
+    process.on('SIGTERM', () => {
+      teardown = true
+      httpLogger.info('disconnecting workers')
+      workers.forEach(w => w.kill('SIGTERM'))
+    })
+  } else {
+    httpLogger.info(`worker ${process.pid} is running`)
+    main()
+  }
+} else {
+  main() // non-clustering
+}