PAY-2563: add solana relay health check (#8120)

dev-tools/compose/docker-compose.pedalboard.prod.yml

@@ -47,7 +47,10 @@ services:
       - discovery
     healthcheck:
       test:
-        ['CMD-SHELL', 'curl -f http://localhost:6001/relay/health || exit 1']
+        [
+          'CMD-SHELL',
+          'curl -f http://localhost:6001/relay/health || exit 1'
+        ]
       interval: 3s
       timeout: 30s
       retries: 3
@@ -74,6 +77,16 @@ services:
     deploy:
       mode: replicated
       replicas: '${DISCOVERY_PROVIDER_REPLICAS}'
+    healthcheck:
+      test:
+        [
+          'CMD-SHELL',
+          'curl -f http://localhost:6002/solana/health_check || exit 1'
+        ]
+      interval: 3s
+      timeout: 30s
+      retries: 3
+      start_period: 5s
 
   sla-auditor:
     container_name: sla-auditor

packages/discovery-provider/plugins/pedalboard/apps/solana-relay/src/index.ts

@@ -15,13 +15,15 @@ import {
 } from './middleware/signerRecovery'
 import { cache } from './routes/cache'
 import { feePayer } from './routes/feePayer'
+import { health } from './routes/health/health'
 
 const main = async () => {
   const { serverHost, serverPort } = config
   const app = express()
   app.use(json())
   app.use(cors())
   app.use(incomingRequestLogger)
+  app.get('/solana/health_check', health)
   app.use(userSignerRecoveryMiddleware)
   app.use(discoveryNodeSignerRecoveryMiddleware)
   app.post('/solana/relay', relay)

packages/discovery-provider/plugins/pedalboard/apps/solana-relay/src/routes/health/health.ts

@@ -0,0 +1,8 @@
+  import { Request, Response, NextFunction } from 'express'
+  import type { RelayRequestBody } from '@audius/sdk'
+
+export const health = async (req: Request, res: Response) => {
+    res.status(200).json({
+        isHealthy: true
+    })
+}