docs(examples/supply-chain-app): fix resource cleanup of shutdown logic

examples/cactus-example-supply-chain-backend/src/main/typescript/infrastructure/supply-chain-app-dummy-infrastructure.ts

@@ -45,6 +45,15 @@ export interface ISupplyChainAppDummyInfrastructureOptions {
   keychain?: IPluginKeychain;
 }
 
+function ledgerStopFailErrorMsg(ledgerName: Readonly<string>): string {
+  return (
+    `Failed to stop ${ledgerName} ledger. This is most likely safe to ignore if the ` +
+    `error states that the container was not running to begin with. This usually means` +
+    `that the process exited before the application boot has finished and it did not` +
+    `have enough time to start launching the ${ledgerName} ledger yet.`
+  );
+}
+
 /**
  * Contains code that is meant to simulate parts of a production grade deployment
  * that would otherwise not be part of the application itself.
@@ -131,12 +140,21 @@ export class SupplyChainAppDummyInfrastructure {
   public async stop(): Promise<void> {
     try {
       this.log.info(`Stopping...`);
-      await Promise.all([
-        this.besu.stop().then(() => this.besu.destroy()),
-        this.quorum.stop().then(() => this.quorum.destroy()),
-        this.fabric.stop().then(() => this.fabric.destroy()),
+      await Promise.allSettled([
+        this.besu
+          .stop()
+          .then(() => this.besu.destroy())
+          .catch((ex) => this.log.warn(ledgerStopFailErrorMsg("Besu"), ex)),
+        this.quorum
+          .stop()
+          .then(() => this.quorum.destroy())
+          .catch((ex) => this.log.warn(ledgerStopFailErrorMsg("Quorum"), ex)),
+        this.fabric
+          .stop()
+          .then(() => this.fabric.destroy())
+          .catch((ex) => this.log.warn(ledgerStopFailErrorMsg("Fabric"), ex)),
       ]);
-      this.log.info(`Stopped OK`);
+      this.log.info(`Ledgers of dummy infrastructure Stopped OK`);
     } catch (ex) {
       this.log.error(`Stopping crashed: `, ex);
       throw ex;

examples/cactus-example-supply-chain-backend/src/main/typescript/supply-chain-app-cli.ts

@@ -21,7 +21,7 @@ export async function launchApp(
     await supplyChainApp.start();
   } catch (ex) {
     console.error(`SupplyChainApp crashed. Existing...`, ex);
-    await supplyChainApp?.stop();
+    await supplyChainApp.stop();
     process.exit(-1);
   }
 }

examples/cactus-example-supply-chain-backend/src/main/typescript/supply-chain-app.ts

@@ -191,15 +191,28 @@ export class SupplyChainApp {
     this.log.debug(`Starting SupplyChainApp...`);
 
     if (!this.options.disableSignalHandlers) {
-      exitHook((callback: IAsyncExitHookDoneCallback) => {
-        console.log(`Executing Registered signal handler to stop container.`);
-        this.stop().then(callback);
+      exitHook((onHookDone: IAsyncExitHookDoneCallback) => {
+        this.log.info("Starting async-exit-hook for supply-chain-app ...");
+        this.stop()
+          .catch((ex: unknown) => {
+            this.log.warn("Failed async-exit-hook for supply-chain-app", ex);
+            throw ex;
+          })
+          .finally(() => {
+            this.log.info("Concluded async-exit-hook for supply-chain-app ...");
+            onHookDone();
+          });
+        this.log.info("Started async-exit-hook for supply-chain-app OK");
       });
-      this.log.debug(`Registered signal handlers for graceful auto-shutdown`);
+      this.log.info("Registered async-exit-hook for supply-chain-app shutdown");
     }
 
+    this.onShutdown(async () => {
+      this.log.info("SupplyChainApp onShutdown() - stopping ledgers...");
+      await this.ledgers.stop();
+      this.log.info("SupplyChainApp onShutdown() - stopped ledgers OK");
+    });
     await this.ledgers.start();
-    this.onShutdown(() => this.ledgers.stop());
 
     const contractsInfo = await this.ledgers.deployContracts();
 
@@ -441,8 +454,12 @@ export class SupplyChainApp {
   }
 
   public async stop(): Promise<void> {
+    let i = 0;
     for (const hook of this.shutdownHooks) {
+      i++;
+      this.log.info("Executing exit hook #%d...", i);
       await hook(); // FIXME add timeout here so that shutdown does not hang
+      this.log.info("Executed exit hook #%d OK", i);
     }
   }
 
@@ -590,15 +607,25 @@ export class SupplyChainApp {
     properties.authorizationConfigJson =
       await this.getOrCreateAuthorizationConfig();
     properties.crpcPort = 0;
+    // We must disable the API server's own shutdown hooks because if we didn't
+    // it would clash with the supply chain app's own shutdown hooks and the
+    // async functions wouldn't be waited for their conclusion leaving the containers
+    // running after the supply chain app NodeJS process has exited.
+    properties.enableShutdownHook = false;
 
     const apiServer = new ApiServer({
       config: properties,
       httpServerApi,
       httpServerCockpit,
       pluginRegistry,
+      enableShutdownHook: false,
     });
 
-    this.onShutdown(() => apiServer.shutdown());
+    this.onShutdown(async () => {
+      this.log.info("SupplyChainApp onShutdown() - stopping API server");
+      await apiServer.shutdown();
+      this.log.info("SupplyChainApp onShutdown() - stopped API server OK");
+    });
 
     await apiServer.start();