feat: add local fallback for S3 writes

Cargo.lock

@@ -2169,6 +2169,7 @@ dependencies = [
  "axum",
  "axum-extra",
  "base64 0.22.1",
+ "bytes",
  "chrono",
  "dotenvy",
  "hex",

Cargo.toml

@@ -16,6 +16,7 @@ time = "0.3"
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
 thiserror = "1"
+bytes = "1"
 
 tracing = "0.1"
 tracing-subscriber = { version = "0.3", features = ["env-filter"] }

docs/api.md

@@ -731,6 +731,8 @@ Authorization: Bearer <admin_token>
 
 凭据加密保存且不通过 API 回传。测试接口执行 Bucket 检查、内部临时对象读写删和公网预签名下载；激活接口会再次测试并原子切换活动端点。活动端点不能直接编辑或删除。
 
+列表响应中的 `local_object_count` 与 `local_stored_bytes` 统计当前实际位于应用服务器的成品。存在活动 S3 时，新对象仍优先写入 S3；若本次 S3 写入失败，则自动回退本地并按实际后端完成下载和到期清理。
+
 ### 11.7 兑换码管理
 
 ```http

docs/s3-storage-plan.md

@@ -39,6 +39,7 @@ flowchart LR
 4. 批处理原图只在 118 的共享 `uploads/orig` 临时保存，Worker 完成或失败后删除，不上传 S3。
 5. 批量 ZIP 在 118 临时生成，64 MiB 以上自动使用 S3 分片上传，上传后删除临时目录。
 6. 每个成品记录写入时的端点 ID。以后切换端点不会使旧文件失联；旧端点凭据会保留到关联对象清空。
+7. 活动 S3 仍是首选后端；连接、凭据或上传失败时，本次成品自动写入 118 本地卷并记录 `storage_backend=local`。S3 恢复后，后续新对象会再次优先写入 S3。
 
 `/api/v1/compress/direct` 保留原有“响应体直接返回图片”的 API 语义，避免破坏现有调用方；网站下载、历史记录下载、普通压缩结果和批量 ZIP 均走 S3。
 
@@ -126,6 +127,7 @@ aws --endpoint-url http://127.0.0.1:3900 \
 - 未授权用户无法取得签名 URL；任务过期后应用下载接口返回 404。
 - 单文件与批任务数据库均记录正确的 `storage_endpoint_id` 和对象键。
 - 切换到第二端点后，新对象进入第二端点，第一端点历史对象仍可下载。
-- S3 停止时同步请求返回 503，批任务保留临时原图并重试，不静默写回本地。
+- S3 停止时同步请求和批任务均完成本地兜底，数据库记录 `storage_backend=local`，下载接口直接从应用服务器返回文件。
+- S3 恢复后下一次新对象重新记录为 `storage_backend=s3`，下载接口恢复 `307` 到签名 URL。
 - 删除 S3 对象失败时，过期任务数据库记录保留并在下一轮重试。
 - 119 磁盘 70%/85% 告警、容器重启、NTP 时间同步和证书续期均验证通过。

frontend/src/app/layouts/PublicLayout.vue

@@ -8,6 +8,8 @@ const auth = useAuthStore()
 const router = useRouter()
 
 const isLoggedIn = computed(() => auth.isLoggedIn)
+const consoleRoute = computed(() => (auth.user?.role === 'admin' ? '/admin' : '/dashboard'))
+const consoleLabel = computed(() => (auth.user?.role === 'admin' ? '管理后台' : '控制台'))
 
 function logout() {
   auth.logout()
@@ -35,10 +37,10 @@ function logout() {
         <div class="flex items-center gap-3">
           <template v-if="isLoggedIn">
             <RouterLink
-              to="/dashboard"
+              :to="consoleRoute"
               class="rounded-md border border-slate-200 bg-white px-3 py-1.5 text-sm text-slate-700 hover:bg-slate-50"
             >
-              控制台
+              {{ consoleLabel }}
             </RouterLink>
             <button
               type="button"

frontend/src/app/router.ts

@@ -81,7 +81,7 @@ export function createAppRouter(pinia: Pinia) {
     }
 
     if ((to.name === 'login' || to.name === 'register') && auth.isLoggedIn) {
-      return { name: 'dashboard' }
+      return { name: auth.user?.role === 'admin' ? 'admin' : 'dashboard' }
     }
 
     if (to.meta?.requiresAdmin && auth.user?.role !== 'admin') {

frontend/src/pages/LoginPage.vue

@@ -22,8 +22,10 @@ async function submit() {
     const resp = await login(email.value.trim(), password.value)
     auth.setAuth(resp.token, resp.user)
 
-    const redirect = typeof route.query.redirect === 'string' ? route.query.redirect : '/dashboard'
-    await router.push(redirect)
+    const defaultRoute = resp.user.role === 'admin' ? '/admin' : '/dashboard'
+    const requestedRoute = typeof route.query.redirect === 'string' ? route.query.redirect : null
+    const redirect = requestedRoute?.startsWith('/') && !requestedRoute.startsWith('//') ? requestedRoute : defaultRoute
+    await router.replace(redirect)
   } catch (err) {
     if (err instanceof ApiError) {
       error.value = `[${err.code}] ${err.message}`

frontend/src/pages/admin/AdminStoragePage.vue

@@ -20,6 +20,8 @@ const loading = ref(true)
 const error = ref<string | null>(null)
 const message = ref<string | null>(null)
 const activeBackend = ref<'local' | 's3'>('local')
+const localObjectCount = ref(0)
+const localStoredBytes = ref(0)
 const endpoints = ref<AdminStorageEndpoint[]>([])
 const editingId = ref<string | null>(null)
 const formOpen = ref(false)
@@ -59,6 +61,8 @@ async function loadEndpoints(clearError = true) {
     const response = await listStorageEndpoints(auth.token)
     endpoints.value = response.endpoints
     activeBackend.value = response.active_backend
+    localObjectCount.value = response.local_object_count
+    localStoredBytes.value = response.local_stored_bytes
   } catch (err) {
     error.value = errorText(err, '加载存储配置失败')
   } finally {
@@ -207,7 +211,7 @@ onMounted(loadEndpoints)
           <p class="text-xs font-semibold uppercase tracking-[0.22em] text-cyan-300">Storage control plane</p>
           <h2 class="mt-3 text-2xl font-semibold">对象存储</h2>
           <p class="mt-2 max-w-2xl text-sm leading-6 text-slate-300">
-            应用完成鉴权后返回短期签名地址，图片与批量 ZIP 的下载流量直接由高带宽 S3 节点承担。每个对象固定绑定写入端点，后续切换或扩容不会影响旧文件。
+            新对象优先写入活动 S3；连接或写入失败时自动保存到应用服务器本地。每个对象固定记录实际写入后端，恢复 S3 后的新文件会自动重新走对象存储。
           </p>
         </div>
         <div class="rounded-xl border border-white/10 bg-white/5 p-4">
@@ -217,12 +221,16 @@ onMounted(loadEndpoints)
               class="rounded-full px-3 py-1 text-xs font-semibold"
               :class="activeBackend === 's3' ? 'bg-emerald-400/15 text-emerald-300' : 'bg-amber-400/15 text-amber-200'"
             >
-              {{ activeBackend === 's3' ? 'S3 已启用' : '本地回退' }}
+              {{ activeBackend === 's3' ? 'S3 优先' : '仅本地' }}
             </span>
           </div>
           <p class="mt-3 text-xs leading-5 text-slate-400">
-            推荐内部 Endpoint 走两台服务器之间的 WireGuard 地址；公网 Endpoint 使用带 TLS 的下载域名。签名默认 5 分钟有效。
+            S3 故障只影响当次写入，下载与到期清理会按对象记录的真实后端执行。签名默认 5 分钟有效。
           </p>
+          <div class="mt-3 flex items-center justify-between border-t border-white/10 pt-3 text-xs">
+            <span class="text-slate-400">本地对象</span>
+            <span class="font-medium text-slate-200">{{ localObjectCount }} 个 · {{ formatBytes(localStoredBytes) }}</span>
+          </div>
         </div>
       </div>
     </section>
@@ -238,7 +246,7 @@ onMounted(loadEndpoints)
       <div class="flex flex-wrap items-center justify-between gap-3">
         <div>
           <h3 class="font-semibold text-slate-900">存储端点</h3>
-          <p class="mt-1 text-sm text-slate-500">同一时间只有一个端点接收新对象，停用端点继续服务其历史对象。</p>
+          <p class="mt-1 text-sm text-slate-500">同一时间只有一个首选 S3 端点；写入失败自动回退本地，停用端点继续服务其历史对象。</p>
         </div>
         <button
           class="rounded-lg bg-slate-900 px-4 py-2 text-sm font-medium text-white hover:bg-slate-800"

frontend/src/services/api.ts

@@ -669,6 +669,8 @@ export interface AdminStorageEndpoint {
 
 export interface AdminStorageEndpointsResponse {
   active_backend: 'local' | 's3'
+  local_object_count: number
+  local_stored_bytes: number
   endpoints: AdminStorageEndpoint[]
 }
 

src/api/admin_storage.rs

@@ -60,6 +60,8 @@ struct StorageEndpointView {
 #[derive(Debug, Serialize)]
 struct StorageEndpointsResponse {
     active_backend: String,
+    local_object_count: i64,
+    local_stored_bytes: i64,
     endpoints: Vec<StorageEndpointView>,
 }
 
@@ -109,6 +111,7 @@ async fn list_storage_endpoints(
     } else {
         "local"
     };
+    let (local_object_count, local_stored_bytes) = local_usage(&state).await?;
     let mut views = Vec::with_capacity(endpoints.len());
     for endpoint in endpoints {
         views.push(endpoint_view(&state, endpoint).await?);
@@ -118,6 +121,8 @@ async fn list_storage_endpoints(
         success: true,
         data: StorageEndpointsResponse {
             active_backend: active_backend.to_string(),
+            local_object_count,
+            local_stored_bytes,
             endpoints: views,
         },
     }))
@@ -536,6 +541,28 @@ async fn endpoint_usage(state: &AppState, endpoint_id: Uuid) -> Result<(i64, i64
     .map_err(|err| AppError::new(ErrorCode::Internal, "统计存储使用量失败").with_source(err))
 }
 
+async fn local_usage(state: &AppState) -> Result<(i64, i64), AppError> {
+    sqlx::query_as::<_, (i64, i64)>(
+        r#"
+        SELECT
+          (SELECT COUNT(*) FROM task_files
+             WHERE status = 'completed'
+               AND storage_backend = 'local'
+               AND COALESCE(storage_key, storage_path) IS NOT NULL)
+            + (SELECT COUNT(*) FROM tasks
+                 WHERE zip_storage_backend = 'local'
+                   AND zip_storage_key IS NOT NULL) AS object_count,
+          COALESCE((SELECT SUM(compressed_size)::BIGINT FROM task_files
+                      WHERE status = 'completed' AND storage_backend = 'local'), 0::BIGINT)
+            + COALESCE((SELECT SUM(zip_size)::BIGINT FROM tasks
+                          WHERE zip_storage_backend = 'local'), 0::BIGINT) AS stored_bytes
+        "#,
+    )
+    .fetch_one(&state.db)
+    .await
+    .map_err(|err| AppError::new(ErrorCode::Internal, "统计本地存储使用量失败").with_source(err))
+}
+
 async fn record_test_result(
     state: &AppState,
     endpoint_id: Uuid,

src/services/storage.rs

@@ -3,12 +3,14 @@ use crate::services::settings;
 use crate::state::AppState;
 
 use aws_sdk_s3::config::{
-    BehaviorVersion, Credentials, Region, RequestChecksumCalculation, ResponseChecksumValidation,
+    retry::RetryConfig, timeout::TimeoutConfig, BehaviorVersion, Credentials, Region,
+    RequestChecksumCalculation, ResponseChecksumValidation,
 };
 use aws_sdk_s3::presigning::PresigningConfig;
 use aws_sdk_s3::primitives::ByteStream;
 use aws_sdk_s3::types::{CompletedMultipartUpload, CompletedPart};
 use aws_sdk_s3::Client;
+use bytes::Bytes;
 use chrono::{DateTime, Datelike, Utc};
 use sqlx::FromRow;
 use std::path::{Path, PathBuf};
@@ -151,8 +153,25 @@ pub async fn store_bytes(
     bytes: Vec<u8>,
     content_type: &str,
 ) -> Result<StoredObject, AppError> {
+    let bytes = Bytes::from(bytes);
     if let Some(endpoint) = active_endpoint(state).await? {
-        let client = client_for(state, &endpoint, EndpointKind::Internal)?;
+        match store_bytes_s3(state, &endpoint, key, bytes.clone(), content_type).await {
+            Ok(stored) => return Ok(stored),
+            Err(err) => log_local_fallback(&endpoint, key, &err),
+        }
+    }
+
+    store_bytes_local(state, key, bytes.as_ref()).await
+}
+
+async fn store_bytes_s3(
+    state: &AppState,
+    endpoint: &StorageEndpoint,
+    key: &str,
+    bytes: Bytes,
+    content_type: &str,
+) -> Result<StoredObject, AppError> {
+    let client = client_for(state, endpoint, EndpointKind::Internal)?;
     let size = bytes.len() as u64;
     let output = client
         .put_object()
@@ -164,15 +183,20 @@ pub async fn store_bytes(
         .await
         .map_err(|err| storage_error("上传 S3 对象失败", err))?;
 
-        return Ok(StoredObject {
+    Ok(StoredObject {
         backend: "s3".to_string(),
         endpoint_id: Some(endpoint.id),
         key: key.to_string(),
         etag: output.e_tag().map(ToOwned::to_owned),
         size,
-        });
+    })
 }
 
+async fn store_bytes_local(
+    state: &AppState,
+    key: &str,
+    bytes: &[u8],
+) -> Result<StoredObject, AppError> {
     let path = local_path(state, key)?;
     if let Some(parent) = path.parent() {
         tokio::fs::create_dir_all(parent).await.map_err(|err| {
@@ -203,8 +227,25 @@ pub async fn store_file(
     })?;
 
     if let Some(endpoint) = active_endpoint(state).await? {
-        let client = client_for(state, &endpoint, EndpointKind::Internal)?;
-        let etag = if metadata.len() >= MULTIPART_THRESHOLD {
+        match store_file_s3(state, &endpoint, key, path, content_type, metadata.len()).await {
+            Ok(stored) => return Ok(stored),
+            Err(err) => log_local_fallback(&endpoint, key, &err),
+        }
+    }
+
+    store_file_local(state, key, path, metadata.len()).await
+}
+
+async fn store_file_s3(
+    state: &AppState,
+    endpoint: &StorageEndpoint,
+    key: &str,
+    path: &Path,
+    content_type: &str,
+    size: u64,
+) -> Result<StoredObject, AppError> {
+    let client = client_for(state, endpoint, EndpointKind::Internal)?;
+    let etag = if size >= MULTIPART_THRESHOLD {
         multipart_upload(&client, &endpoint.bucket, key, path, content_type).await?
     } else {
         let body = ByteStream::from_path(path).await.map_err(|err| {
@@ -223,15 +264,21 @@ pub async fn store_file(
             .map(ToOwned::to_owned)
     };
 
-        return Ok(StoredObject {
+    Ok(StoredObject {
         backend: "s3".to_string(),
         endpoint_id: Some(endpoint.id),
         key: key.to_string(),
         etag,
-            size: metadata.len(),
-        });
+        size,
+    })
 }
 
+async fn store_file_local(
+    state: &AppState,
+    key: &str,
+    path: &Path,
+    size: u64,
+) -> Result<StoredObject, AppError> {
     let destination = local_path(state, key)?;
     if let Some(parent) = destination.parent() {
         tokio::fs::create_dir_all(parent).await.map_err(|err| {
@@ -247,10 +294,21 @@ pub async fn store_file(
         endpoint_id: None,
         key: destination.to_string_lossy().to_string(),
         etag: None,
-        size: metadata.len(),
+        size,
     })
 }
 
+fn log_local_fallback(endpoint: &StorageEndpoint, key: &str, err: &AppError) {
+    tracing::warn!(
+        storage_endpoint_id = %endpoint.id,
+        storage_endpoint = %endpoint.name,
+        object_key = %key,
+        error = %err,
+        fallback_backend = "local",
+        "S3 write failed; storing object on local disk"
+    );
+}
+
 pub async fn read_bytes(state: &AppState, object: &ObjectLocator) -> Result<Vec<u8>, AppError> {
     if object.backend == "local" {
         return tokio::fs::read(&object.key).await.map_err(|err| {
@@ -509,6 +567,12 @@ fn build_client(
         .region(Region::new(region.to_string()))
         .endpoint_url(endpoint_url)
         .force_path_style(force_path_style)
+        .retry_config(RetryConfig::standard().with_max_attempts(2))
+        .timeout_config(
+            TimeoutConfig::builder()
+                .connect_timeout(Duration::from_secs(3))
+                .build(),
+        )
         .request_checksum_calculation(RequestChecksumCalculation::WhenRequired)
         .response_checksum_validation(ResponseChecksumValidation::WhenRequired)
         .build();