From f91bd6851f417b54390e66734032c688380cc5ca Mon Sep 17 00:00:00 2001
From: Alice Gaudon <alice@gaudon.pro>
Date: Fri, 26 Mar 2021 10:32:02 +0100
Subject: [PATCH] Application: make start/stop sturdier, catch more stop
 signals

---
 src/Application.ts | 81 +++++++++++++++++++++++++++++++++++-----------
 1 file changed, 63 insertions(+), 18 deletions(-)

diff --git a/src/Application.ts b/src/Application.ts
index 3b90dfc..b37b3be 100644
--- a/src/Application.ts
+++ b/src/Application.ts
@@ -29,6 +29,8 @@ export default abstract class Application implements Extendable<ApplicationCompo
     private cacheProvider?: CacheProvider;
 
     private ready: boolean = false;
+    private started: boolean = false;
+    private busy: boolean = false;
 
     protected constructor(version: string, ignoreCommandLine: boolean = false) {
         this.version = version;
@@ -59,6 +61,10 @@ export default abstract class Application implements Extendable<ApplicationCompo
     }
 
     public async start(): Promise<void> {
+        if (this.started) throw new Error('Application already started');
+        if (this.busy) throw new Error('Application busy');
+        this.busy = true;
+
         // Load core version
         const file = this.isInNodeModules() ?
             path.join(__dirname, '../../package.json') :
@@ -73,22 +79,28 @@ export default abstract class Application implements Extendable<ApplicationCompo
         logger.info(`${config.get('app.name')} v${this.version} | swaf v${this.coreVersion}`);
 
         // Catch interrupt signals
-        process.once('SIGINT', () => {
+        const exitHandler = () => {
             this.stop().catch(console.error);
-        });
+        };
+        process.once('exit', exitHandler);
+        process.once('SIGINT', exitHandler);
+        process.once('SIGUSR1', exitHandler);
+        process.once('SIGUSR2', exitHandler);
+        process.once('uncaughtException', exitHandler);
 
         // Register migrations
         MysqlConnectionManager.registerMigrations(this.getMigrations());
 
-        // Process command line
-        if (!this.ignoreCommandLine && await this.processCommandLine()) {
-            await this.stop();
-            return;
-        }
-
         // Register all components and alike
         await this.init();
 
+        // Process command line
+        if (!this.ignoreCommandLine && await this.processCommandLine()) {
+            this.started = true;
+            this.busy = false;
+            return;
+        }
+
         // Security
         if (process.env.NODE_ENV === 'production') {
             await this.checkSecuritySettings();
@@ -203,26 +215,54 @@ export default abstract class Application implements Extendable<ApplicationCompo
         this.routes(initRouter, handleRouter);
 
         this.ready = true;
+        this.started = true;
+        this.busy = false;
     }
 
     protected async processCommandLine(): Promise<boolean> {
         const args = process.argv;
+        // Flags
+        const flags = {
+            verbose: false,
+            fullHttpRequests: false,
+        };
+        let mainCommand: string | null = null;
+        const mainCommandArgs: string[] = [];
         for (let i = 2; i < args.length; i++) {
             switch (args[i]) {
                 case '--verbose':
-                    logger.setSettings({minLevel: "trace"});
+                    flags.verbose = true;
                     break;
                 case '--full-http-requests':
-                    LogRequestsComponent.logFullHttpRequests();
+                    flags.fullHttpRequests = true;
                     break;
                 case 'migration':
-                    await MysqlConnectionManager.migrationCommand(args.slice(i + 1));
-                    return true;
+                    if (mainCommand === null) mainCommand = args[i];
+                    else throw new Error(`Only one main command can be used at once (${mainCommand},${args[i]})`);
+                    break;
                 default:
-                    logger.warn('Unrecognized argument', args[i]);
+                    if (mainCommand) mainCommandArgs.push(args[i]);
+                    else logger.fatal('Unrecognized argument', args[i]);
                     return true;
             }
         }
+
+        if (flags.verbose) logger.setSettings({minLevel: "trace"});
+        if (flags.fullHttpRequests) LogRequestsComponent.logFullHttpRequests();
+
+        if (mainCommand) {
+            switch (mainCommand) {
+                case 'migration':
+                    await MysqlConnectionManager.migrationCommand(mainCommandArgs);
+                    await this.stop();
+                    break;
+                default:
+                    logger.fatal('Unimplemented main command', mainCommand);
+                    break;
+            }
+            return true;
+        }
+
         return false;
     }
 
@@ -247,13 +287,18 @@ export default abstract class Application implements Extendable<ApplicationCompo
     }
 
     public async stop(): Promise<void> {
-        logger.info('Stopping application...');
+        if (this.started && !this.busy) {
+            this.busy = true;
+            logger.info('Stopping application...');
 
-        for (const component of this.components) {
-            await component.stop?.();
+            for (const component of this.components) {
+                await component.stop?.();
+            }
+
+            logger.info(`${this.constructor.name} stopped properly.`);
+            this.started = false;
+            this.busy = false;
         }
-
-        logger.info(`${this.constructor.name} v${this.version} - bye`);
     }
 
     private routes(initRouter: Router, handleRouter: Router) {