{"id":"cd6998448e6dd871","repo":"gofiber/fiber","slug":"file-failed-to-store-file-q-to-q-w","errorCode":null,"errorMessage":"file: failed to store file: %q to %q: %w","messagePattern":"file: failed to store file: %q to %q: %w","errorType":"exception","errorClass":"ErrFileStore","httpStatus":null,"severity":"error","filePath":"ctx.go","lineNumber":600,"sourceCode":"\t\treturn fmt.Errorf(\"%w: %q: %w\", ErrFileRead, fileheader.Filename, fasthttp.ErrBodyTooLarge)\n\t}\n\n\tbuf := bytebufferpool.Get()\n\tdefer bytebufferpool.Put(buf)\n\n\tlimitedReader := io.LimitReader(file, int64(maxUploadSize)+1)\n\tif _, err = buf.ReadFrom(limitedReader); err != nil {\n\t\treturn fmt.Errorf(\"%w: %q: %w\", ErrFileRead, fileheader.Filename, err)\n\t}\n\n\tif buf.Len() > maxUploadSize {\n\t\treturn fmt.Errorf(\"%w: %q: %w\", ErrFileRead, fileheader.Filename, fasthttp.ErrBodyTooLarge)\n\t}\n\n\tdata := append([]byte(nil), buf.Bytes()...)\n\n\tif err := storage.SetWithContext(c.Context(), path, data, 0); err != nil {\n\t\treturn fmt.Errorf(\"%w: %q to %q: %w\", ErrFileStore, fileheader.Filename, path, err)\n\t}\n\n\treturn nil\n}\n\n// Secure returns whether a secure connection was established.\nfunc (c *DefaultCtx) Secure() bool {\n\treturn c.Scheme() == schemeHTTPS\n}\n\n// Status sets the HTTP status for the response.\n// This method is chainable.\nfunc (c *DefaultCtx) Status(status int) Ctx {\n\tc.fasthttp.Response.SetStatusCode(status)\n\treturn c\n}\n\n// String returns unique string representation of the ctx.","sourceCodeStart":582,"sourceCodeEnd":618,"githubUrl":"https://github.com/gofiber/fiber/blob/9a4c7e57fe0b080a04235d28a4b0d2b4b353d58c/ctx.go#L582-L618","documentation":"Returned by Ctx.SaveFileToStorage when the external Storage backend's SetWithContext fails to persist the uploaded file. It wraps ErrFileStore with the source filename, destination path, and the storage layer's error. This is the final step after the file was successfully read into memory.","triggerScenarios":"Calling c.SaveFileToStorage(fh, path, storage) where storage.SetWithContext returns an error: the remote store (S3, Redis, etc.) is unreachable, returns a permission/quota error, or the request context was cancelled before the write completed.","commonSituations":"Misconfigured storage backend credentials, network outage to the storage service, expired storage session, the destination path/key is invalid or already exists in a write-once bucket, or the client cancelled the request mid-store.","solutions":["Inspect the wrapped storage error to determine if it is auth, quota, network, or context-cancellation.","Verify storage backend connectivity and credentials independently.","Use a retry-with-backoff for transient storage failures (network, throttling).","Check the destination path is valid for the storage scheme (e.g. no leading slash for some S3 keys)."],"exampleFix":"// before\nerr := c.SaveFileToStorage(fh, path, storage)\n\n// after\nerr := c.SaveFileToStorage(fh, path, storage)\nif err != nil {\n    if errors.Is(err, fiber.ErrFileStore) {\n        log.Errorf(\"storage write failed for %q: %v\", fh.Filename, err)\n        return c.Status(fiber.StatusBadGateway).\n            SendString(\"storage unavailable\")\n    }\n    return err\n}","handlingStrategy":"retry","validationCode":"// Verify storage connectivity before the upload handler\nif err := storage.SetWithContext(ctx, \"healthcheck\", []byte(\"ok\"), time.Second); err != nil {\n    return fmt.Errorf(\"storage unreachable: %w\", err)\n}","typeGuard":null,"tryCatchPattern":"if err := c.SaveFileToStorage(fh, path, storage); err != nil {\n    if errors.Is(err, fiber.ErrFileStore) {\n        // retry transient backend errors, else 502\n        return c.Status(fiber.StatusBadGateway).SendString(\"storage error\")\n    }\n    return err\n}","preventionTips":["Health-check the storage backend at startup.","Use retry-with-backoff for transient storage failures.","Validate the destination path/key format for the storage scheme.","Use a detached context for writes that must survive client disconnect."],"tags":["upload","storage","backend","network","go"],"analyzedSha":"9a4c7e57fe0b080a04235d28a4b0d2b4b353d58c","analyzedAt":"2026-08-04T21:44:03.395Z","schemaVersion":2}