feat(api): configurable max pool connections

This should help with failing health checks while the crawler is running.

Quick math: 10 users, 30 songs each, each song requires at least 3
queries => 900 db queries every minute.

With the default of 10 pool connections, this blocks all available db
bandwidth for some time and causes slow UI and failing healthchecks.

README.md

@@ -41,6 +41,7 @@ All configuration must be set as environment variables. Default values are added
 - `DB_USERNAME`: _Required_, Database username
 - `DB_PASSWORD`: _Required_, Database password
 - `DB_DATABASE`: _Required_, Database database
+- `DB_POOL_MAX`: **50**, max concurrent database connections
 
 #### Sentry
 

charts/listory/templates/deployment.yaml

@@ -37,6 +37,8 @@ spec:
                   key: postgres-password
             - name: DB_DATABASE
               value: {{ .Values.externalDatabase.database }}
+            - name: DB_POOL_MAX
+              value: "{{ .Values.database.poolMax }}"
             - name: JWT_SECRET
               valueFrom:
                 secretKeyRef:

charts/listory/values.yaml

@@ -75,6 +75,9 @@ externalDatabase:
   password:
   database:
 
+database:
+  poolMax: 50
+
 spotify:
   clientId:
   clientSecret:

src/config/config.module.ts

@@ -36,6 +36,7 @@ import { ConfigModule as NestConfigModule } from "@nestjs/config";
         DB_USERNAME: Joi.string().required(),
         DB_PASSWORD: Joi.string().required(),
         DB_DATABASE: Joi.string().required(),
+        DB_POOL_MAX: Joi.number().default(50),
 
         // Sentry (Optional)
         SENTRY_ENABLED: Joi.boolean().default(false),

src/database/database.module.ts

@@ -20,6 +20,11 @@ export const DatabaseModule = TypeOrmModule.forRootAsync({
     migrationsRun: true,
     migrations: [join(__dirname, "migrations", "*.{ts,js}")],
 
+    // PG Driver Options
+    extra: {
+      max: config.get<number>("DB_POOL_MAX"),
+    },
+
     // Debug/Development Options
     //
     // logging: true,