From 17adb818bedc390a024fef722d9da67656b93764 Mon Sep 17 00:00:00 2001
From: Jerko Steiner <jerko.steiner@gmail.com>
Date: Sat, 12 Oct 2019 08:44:21 -0500
Subject: [PATCH] Add ability to run server cluster

---
 packages/server/src/application/Bootstrap.ts  |  2 +
 .../server/src/application/ServerBootstrap.ts | 36 +++++++++++-
 packages/server/src/cli/run.ts                | 55 +++++++++++++------
 3 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/packages/server/src/application/Bootstrap.ts b/packages/server/src/application/Bootstrap.ts
index 99d09cb..121ccad 100644
--- a/packages/server/src/application/Bootstrap.ts
+++ b/packages/server/src/application/Bootstrap.ts
@@ -8,6 +8,8 @@ export interface Bootstrap {
   readonly database: TypeORMDatabase
   getConfig(): Config
   listen(port?: number | string, hostname?: string): Promise<void>
+  startCluster(
+    workers: number, port?: number | string, hostname?: string): Promise<void>
   getAddress(): AddressInfo | string
   close(): Promise<void>
 }
diff --git a/packages/server/src/application/ServerBootstrap.ts b/packages/server/src/application/ServerBootstrap.ts
index 8f8fdc2..3817efa 100644
--- a/packages/server/src/application/ServerBootstrap.ts
+++ b/packages/server/src/application/ServerBootstrap.ts
@@ -1,5 +1,7 @@
+import { TypeORMDatabase, TypeORMLogger } from '@rondo.dev/db-typeorm'
 import assert from 'assert'
 import { createNamespace, Namespace } from 'cls-hooked'
+import cluster from 'cluster'
 import { Server } from 'http'
 import { AddressInfo } from 'net'
 import { loggerFactory } from '../logger'
@@ -8,7 +10,7 @@ import { Bootstrap } from './Bootstrap'
 import { Config } from './Config'
 import { ServerConfigurator } from './configureServer'
 import { createServer } from './createServer'
-import { TypeORMDatabase, TypeORMLogger } from '@rondo.dev/db-typeorm'
+
 
 export interface ServerBootstrapParams {
   readonly config: Config
@@ -79,7 +81,7 @@ export class ServerBootstrap implements Bootstrap {
 
   async listen(
     port: number | string | undefined = process.env.PORT || 3000,
-    hostname: string | undefined= process.env.BIND_HOST,
+    hostname: string | undefined = process.env.BIND_HOST,
   ) {
     const apiLogger = loggerFactory.getLogger('api')
     try {
@@ -91,6 +93,36 @@ export class ServerBootstrap implements Bootstrap {
     }
   }
 
+  async startCluster(
+    workers: number,
+    port?: number | string,
+    hostname?: string,
+  ) {
+    const apiLogger = loggerFactory.getLogger('api')
+
+    if (cluster.isMaster) {
+      apiLogger.info('Started master process %d, starting %d workers...',
+        process.pid, workers)
+
+      // Fork workers.
+      for (let i = 0; i < workers; i++) {
+        cluster.fork({
+          WORKER_ID: i + 1,
+        })
+      }
+
+      cluster.on('exit', (worker, code, signal) => {
+        console.log(`worker ${worker.process.pid} died`)
+      })
+    } else {
+      await this.listen(port, hostname)
+      apiLogger.info(
+        'Started worker %d (worker id %s)', process.pid, process.env.WORKER_ID)
+    }
+  }
+
+
+
   protected async start(
     port: number | string | undefined = process.env.PORT,
     hostname?: string,
diff --git a/packages/server/src/cli/run.ts b/packages/server/src/cli/run.ts
index b292f1a..3b94402 100644
--- a/packages/server/src/cli/run.ts
+++ b/packages/server/src/cli/run.ts
@@ -1,8 +1,28 @@
-import { Bootstrap } from "../application";
-import { argparse, arg } from "@rondo.dev/argparse";
+import { arg, argparse } from '@rondo.dev/argparse'
+import { cpus } from 'os'
+import { Bootstrap } from '../application'
+
+const numberOfCPUs = cpus().length
+
+const startArgs = {
+  host: arg('string', {
+    description: '',
+  }),
+  socket: arg('number', {
+    alias: 's',
+    description: 'Socket to listen on',
+  }),
+  port: arg('number', {
+    default: 3000,
+    alias: 'p',
+    description: 'Port to listen on',
+  }),
+  help: arg('boolean', {alias: 'h'}),
+}
 
 export function run(bootstrap: Bootstrap, argv: string[]) {
-  const choices: Array<keyof typeof commands> = ['start', 'migrate']
+  const choices: Array<keyof typeof commands> = Object
+  .keys(commands) as Array<keyof typeof commands>
   const {parse} = argparse({
     command: arg('string', {
       default: 'start',
@@ -24,24 +44,23 @@ export function run(bootstrap: Bootstrap, argv: string[]) {
 
 const commands = {
   async start(bootstrap: Bootstrap, argv: string[]) {
-    const {parse} = argparse({
-      host: arg('string', {
-        description: '',
-      }),
-      socket: arg('number', {
-        alias: 's',
-        description: 'Socket to listen on',
-      }),
-      port: arg('number', {
-        default: 3000,
-        alias: 'p',
-        description: 'Port to listen on',
-      }),
-      help: arg('boolean', {alias: 'h'}),
-    })
+    const {parse} = argparse(startArgs, 'Start the server')
     const args = parse(argv)
     await bootstrap.listen(args.port || args.socket, args.host)
   },
+  async cluster(bootstrap: Bootstrap, argv: string[]) {
+    const {parse} = argparse({
+      ...startArgs,
+      workers: arg('number', {
+        alias: 'w',
+        description: 'Number of workers to start',
+        default: numberOfCPUs,
+      }),
+    }, 'Start in cluster')
+    const args = parse(argv)
+    await bootstrap
+    .startCluster(args.workers, args.port || args.socket, args.host)
+  },
   async migrate(bootstrap: Bootstrap, argv: string[]) {
     const {parse} = argparse({
       undo: arg('boolean', {