(core) resolved some divergence in mergedServerMain

app/server/lib/FlexServer.ts

@@ -1132,7 +1132,6 @@ export class FlexServer implements GristServer {
     await this.loadConfig();
     this.addComm();
 
-    await this.create.configure?.();
     if (!isSingleUserMode()) {
       const externalStorage = appSettings.section('externalStorage');
       const haveExternalStorage = Object.values(externalStorage.nested)
@@ -1143,6 +1142,7 @@ export class FlexServer implements GristServer {
         this._disableExternalStorage = true;
         externalStorage.flag('active').set(false);
       }
+      await this.create.configure?.();
       const workers = this._docWorkerMap;
       const docWorkerId = await this._addSelfAsWorker(workers);
 

app/server/lib/ICreate.ts

@@ -50,6 +50,7 @@ export interface ICreateActiveDocOptions {
 export interface ICreateStorageOptions {
   name: string;
   check(): boolean;
+  checkBackend?(): Promise<void>;
   create(purpose: 'doc'|'meta', extraPrefix: string): ExternalStorage|undefined;
 }
 
@@ -119,7 +120,10 @@ export function makeSimpleCreator(opts: {
     },
     async configure() {
       for (const s of storage || []) {
-        if (s.check()) { break; }
+        if (s.check()) {
+          await s.checkBackend?.();
+          break;
+        }
       }
     },
     ...(opts.shell && {

app/server/lib/MinIOExternalStorage.ts

@@ -107,6 +107,11 @@ export class MinIOExternalStorage implements ExternalStorage {
     }
   }
 
+  public async hasVersioning(): Promise<Boolean> {
+    const versioning = await this._s3.getBucketVersioning(this.bucket);
+    return versioning && versioning.Status === 'Enabled';
+  }
+
   public async versions(key: string, options?: { includeDeleteMarkers?: boolean }) {
     const results: minio.BucketItem[] = [];
     await new Promise((resolve, reject) => {

app/server/lib/configureMinIOExternalStorage.ts

@@ -60,3 +60,16 @@ export function checkMinIOExternalStorage() {
     region
   };
 }
+
+export async function checkMinIOBucket() {
+  const options = checkMinIOExternalStorage();
+  if (!options) {
+    throw new Error('Configuration check failed for MinIO backend storage.');
+  }
+
+  const externalStorage = new MinIOExternalStorage(options.bucket, options);
+  if (!await externalStorage.hasVersioning()) {
+    await externalStorage.close();
+    throw new Error(`FATAL: the MinIO bucket "${options.bucket}" does not have versioning enabled`);
+  }
+}

app/server/mergedServerMain.ts

@@ -106,45 +106,50 @@ export async function main(port: number, serverTypes: ServerType[],
   server.addApiMiddleware();
   await server.addBillingMiddleware();
 
-  await server.start();
+  try {
+    await server.start();
 
-  if (includeHome) {
-    server.addUsage();
-    if (!includeDocs) {
-      server.addDocApiForwarder();
+    if (includeHome) {
+      server.addUsage();
+      if (!includeDocs) {
+        server.addDocApiForwarder();
+      }
+      server.addJsonSupport();
+      await server.addLandingPages();
+      // todo: add support for home api to standalone app
+      server.addHomeApi();
+      server.addBillingApi();
+      server.addNotifier();
+      await server.addTelemetry();
+      await server.addHousekeeper();
+      await server.addLoginRoutes();
+      server.addAccountPage();
+      server.addBillingPages();
+      server.addWelcomePaths();
+      server.addLogEndpoint();
+      server.addGoogleAuthEndpoint();
+      server.addInstallEndpoints();
     }
-    server.addJsonSupport();
-    await server.addLandingPages();
-    // todo: add support for home api to standalone app
-    server.addHomeApi();
-    server.addBillingApi();
-    server.addNotifier();
-    await server.addTelemetry();
-    await server.addHousekeeper();
-    await server.addLoginRoutes();
-    server.addAccountPage();
-    server.addBillingPages();
-    server.addWelcomePaths();
-    server.addLogEndpoint();
-    server.addGoogleAuthEndpoint();
-    server.addInstallEndpoints();
+
+    if (includeDocs) {
+      server.addJsonSupport();
+      await server.addTelemetry();
+      await server.addDoc();
+    }
+
+    if (includeHome) {
+      server.addClientSecrets();
+    }
+
+    server.finalize();
+
+    server.checkOptionCombinations();
+    server.summary();
+    return server;
+  } catch(e) {
+    await server.close();
+    throw e;
   }
-
-  if (includeDocs) {
-    server.addJsonSupport();
-    await server.addTelemetry();
-    await server.addDoc();
-  }
-
-  if (includeHome) {
-    server.addClientSecrets();
-  }
-
-  server.finalize();
-
-  server.checkOptionCombinations();
-  server.summary();
-  return server;
 }