Feat: Auto-resolve backend API base URL so Swarm redeploys no longer break proxied requests (fetch failed)

src/app/api/[...route]/route.ts

@@ -1,4 +1,5 @@
 import { NextRequest, NextResponse } from 'next/server';
+import { getApiBase, resetApiBase } from '@/lib/api-base';
 
 export async function GET(req: NextRequest, props: { params: Promise<{ route: string[] }> }) {
   return handleProxy(req, props);
@@ -27,9 +28,10 @@ async function handleProxy(req: NextRequest, { params }: { params: Promise<{ rou
     
     const url = new URL(req.url);
     
-    // INTERNAL_API_URL is read at RUNTIME (not baked at build time like NEXT_PUBLIC_*)
-    // This allows Docker Swarm / Portainer to set the backend URL dynamically
-    const localBase = process.env.INTERNAL_API_URL || process.env.NEXT_PUBLIC_API_URL || 'http://127.0.0.1:3001';
+    // INTERNAL_API_URL is read at RUNTIME (not baked at build time like NEXT_PUBLIC_*).
+    // getApiBase() probes configured URLs and transparently falls back to the stable
+    // Swarm service alias if the configured one (e.g. task hostname ...-0) is unreachable.
+    const localBase = await getApiBase();
     const destinationUrl = `${localBase}/api/${route}${url.search}`;
     
     // Prepare headers
@@ -67,7 +69,7 @@ async function handleProxy(req: NextRequest, { params }: { params: Promise<{ rou
       headers,
       body: body,
       cache: 'no-store', // Prevent Next.js from aggressively caching the backend response
-      // @ts-ignore
+      // @ts-expect-error - `duplex` is required for streaming bodies in older fetch typings
       duplex: hasBody ? 'half' : undefined,
     });
     
@@ -93,8 +95,11 @@ async function handleProxy(req: NextRequest, { params }: { params: Promise<{ rou
     }
 
     return nextResponse;
-  } catch (error: any) {
+  } catch (error) {
+    // Backend may have been redeployed (task hostname changed) — re-resolve next request.
+    resetApiBase();
     console.error('[Proxy Error]', error);
-    return NextResponse.json({ ok: false, message: error.message }, { status: 500 });
+    const message = error instanceof Error ? error.message : 'Unknown proxy error';
+    return NextResponse.json({ ok: false, message }, { status: 500 });
   }
 }