feat: dynamic database storage size with PVC expansion

- Add dbStorageSize column to Application entity (default: 1Gi)
- Add dbStorageSize to CreateApplicationDto, frontend types
- Use dynamic storage size in K8s deployDatabase instead of hardcoded 5Gi
- Deploy page: storage size selector with +/- buttons (min 1GB, max 100GB)
- Auto-suggest storage based on DB dump file size (3x dump size, min 1GB)
- Show DB storage in Review step
- App detail: Database Storage section with expand button
- GET /applications/:id/db-storage — read current PVC size from K8s
- PATCH /applications/:id/db-storage — expand PVC (only increase, no shrink)
- PVC resize uses JSON patch on K8s API

backend/src/applications/applications.controller.ts

@@ -93,6 +93,48 @@ export class ApplicationsController {
     };
   }
 
+  @Get(':id/db-storage')
+  @ApiOperation({ summary: 'Get current database PVC storage size' })
+  async getDbStorage(@Param('id') id: string, @Request() req: any) {
+    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
+    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);
+
+    if (app.databaseType === DatabaseType.NONE) {
+      throw new BadRequestException('This application does not have a database configured');
+    }
+
+    const currentSize = await this.kubernetesService.getDatabasePvcSize(app);
+    return { currentSize, savedSize: app.dbStorageSize || '1Gi' };
+  }
+
+  @Patch(':id/db-storage')
+  @ApiOperation({ summary: 'Resize (expand) database PVC storage' })
+  async resizeDbStorage(
+    @Param('id') id: string,
+    @Request() req: any,
+    @Body() body: { size: string },
+  ) {
+    const isStaff = req.user.role === UserRole.ADMIN || req.user.role === UserRole.TECHNICAL;
+    const app = await this.applicationsService.findOne(id, isStaff ? undefined : req.user.id);
+
+    if (app.databaseType === DatabaseType.NONE) {
+      throw new BadRequestException('This application does not have a database configured');
+    }
+
+    if (!body.size || !/^\d+Gi$/.test(body.size)) {
+      throw new BadRequestException('Size must be in format like "1Gi", "5Gi", "10Gi"');
+    }
+
+    const result = await this.kubernetesService.resizeDatabasePvc(app, body.size);
+
+    if (result.success) {
+      // Update the saved size in the DB
+      await this.applicationsService.update(id, app.userId, { dbStorageSize: body.size } as any);
+    }
+
+    return result;
+  }
+
   @Get()
   @ApiOperation({ summary: 'List my applications' })
   async findAll(@Request() req: any) {

backend/src/applications/dto/application.dto.ts

@@ -57,6 +57,11 @@ export class CreateApplicationDto {
   @IsString()
   dbPassword?: string;
 
+  @ApiPropertyOptional({ example: '1Gi', description: 'Database PVC storage size (e.g. 1Gi, 5Gi, 10Gi). Default: 1Gi' })
+  @IsOptional()
+  @IsString()
+  dbStorageSize?: string;
+
   @ApiPropertyOptional({ example: 'https://github.com/user/repo.git' })
   @IsOptional()
   @IsString()

backend/src/applications/entities/application.entity.ts

@@ -44,6 +44,9 @@ export class Application {
   @Column({ nullable: true })
   dbPassword: string;
 
+  @Column({ nullable: true, default: '1Gi' })
+  dbStorageSize: string; // PVC storage size for database (e.g. '1Gi', '5Gi', '10Gi')
+
   @Column({ nullable: true })
   gitUrl: string;
 

backend/src/kubernetes/kubernetes.service.ts

@@ -26,6 +26,7 @@ interface ManifestContext {
   dbUsername: string;
   dbPassword: string;
   dbVersion: string;
+  dbStorageSize: string;
 }
 
 @Injectable()
@@ -99,6 +100,7 @@ export class KubernetesService implements OnModuleInit {
       dbUsername: app.dbUsername || 'appuser',
       dbPassword: app.dbPassword || this.generatePassword(),
       dbVersion: app.dbVersion || '',
+      dbStorageSize: app.dbStorageSize || '1Gi',
     };
 
     const manifests: Record<string, any> = {};
@@ -396,7 +398,7 @@ export class KubernetesService implements OnModuleInit {
     await this.createDbSecret(coreApi, ctx.namespace, ctx.appName, ctx.dbPassword, ctx.dbUsername);
 
     // Create PVC for DB
-    await this.createPVC(coreApi, ctx.namespace, dbName, '5Gi');
+    await this.createPVC(coreApi, ctx.namespace, dbName, ctx.dbStorageSize);
 
     // Deploy database
     const isPostgres = ctx.databaseType === DatabaseType.POSTGRESQL;
@@ -1025,6 +1027,72 @@ export class KubernetesService implements OnModuleInit {
     return { success: true, logs };
   }
 
+  /**
+   * Resize (expand) the database PVC for an application.
+   * K8s only supports PVC expansion, not shrinking.
+   */
+  async resizeDatabasePvc(app: Application, newSize: string): Promise<{ success: boolean; message: string }> {
+    const { coreApi } = await this.getK8sClient(app.clusterId);
+    const namespace = `user-${app.userId.split('-')[0]}`;
+    const pvcName = `${app.name}-db`;
+
+    try {
+      // Read current PVC to check current size
+      const currentPvc = await coreApi.readNamespacedPersistentVolumeClaim(pvcName, namespace);
+      const currentSize = currentPvc.body.spec?.resources?.requests?.storage || '1Gi';
+
+      const currentGi = parseInt(currentSize.replace('Gi', ''), 10) || 1;
+      const newGi = parseInt(newSize.replace('Gi', ''), 10) || 1;
+
+      if (newGi <= currentGi) {
+        return { success: false, message: `New size (${newSize}) must be larger than current size (${currentSize})` };
+      }
+
+      // Patch PVC to expand
+      const patch = [
+        {
+          op: 'replace',
+          path: '/spec/resources/requests/storage',
+          value: newSize,
+        },
+      ];
+
+      await coreApi.patchNamespacedPersistentVolumeClaim(
+        pvcName,
+        namespace,
+        patch,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        undefined,
+        { headers: { 'Content-Type': 'application/json-patch+json' } },
+      );
+
+      this.logger.log(`Resized PVC ${pvcName} from ${currentSize} to ${newSize}`);
+      return { success: true, message: `Database storage expanded from ${currentSize} to ${newSize}` };
+    } catch (e: any) {
+      this.logger.error(`Failed to resize PVC ${pvcName}: ${e.message}`);
+      return { success: false, message: e.body?.message || e.message || 'Failed to resize database storage' };
+    }
+  }
+
+  /**
+   * Get current PVC size for an application's database.
+   */
+  async getDatabasePvcSize(app: Application): Promise<string> {
+    try {
+      const { coreApi } = await this.getK8sClient(app.clusterId);
+      const namespace = `user-${app.userId.split('-')[0]}`;
+      const pvcName = `${app.name}-db`;
+
+      const pvc = await coreApi.readNamespacedPersistentVolumeClaim(pvcName, namespace);
+      return pvc.body.spec?.resources?.requests?.storage || app.dbStorageSize || '1Gi';
+    } catch {
+      return app.dbStorageSize || '1Gi';
+    }
+  }
+
   private generatePassword(length = 24): string {
     const chars = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%';
     let password = '';