From ff1301d28f1d5567ecf65ee21b67f45cd0ccba78 Mon Sep 17 00:00:00 2001
From: Oliver Sand <oliver.sand@sda-se.com>
Date: Wed, 25 Nov 2020 16:52:29 +0100
Subject: [PATCH] Warn if app-backend can't start-up because missing dir

---
 .changeset/brave-rats-obey.md             |  5 +++++
 plugins/app-backend/src/service/router.ts | 12 +++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/brave-rats-obey.md

diff --git a/.changeset/brave-rats-obey.md b/.changeset/brave-rats-obey.md
new file mode 100644
index 0000000000..a09d922763
--- /dev/null
+++ b/.changeset/brave-rats-obey.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-app-backend': patch
+---
+
+Warn if the app-backend can't start-up because the static directory that should be served is unavailable.
diff --git a/plugins/app-backend/src/service/router.ts b/plugins/app-backend/src/service/router.ts
index b435ec15f1..65cbddaae6 100644
--- a/plugins/app-backend/src/service/router.ts
+++ b/plugins/app-backend/src/service/router.ts
@@ -21,6 +21,7 @@ import { Logger } from 'winston';
 import { notFoundHandler, resolvePackagePath } from '@backstage/backend-common';
 import { Config } from '@backstage/config';
 import { injectConfig, readConfigs } from '../lib/config';
+import fs from 'fs-extra';
 
 export interface RouterOptions {
   config: Config;
@@ -35,9 +36,18 @@ export async function createRouter(
   const { config, logger, appPackageName, staticFallbackHandler } = options;
 
   const appDistDir = resolvePackagePath(appPackageName, 'dist');
-  logger.info(`Serving static app content from ${appDistDir}`);
   const staticDir = resolvePath(appDistDir, 'static');
 
+  if (!(await fs.pathExists(staticDir))) {
+    logger.warn(
+      `Can't serve static app content from ${staticDir}, directory doesn't exist`,
+    );
+
+    return Router();
+  }
+
+  logger.info(`Serving static app content from ${appDistDir}`);
+
   const appConfigs = await readConfigs({
     config,
     appDistDir,