{"record":{"id":"34b4146bf9632a24","repo":"flipped-aurora/gin-vue-admin","slug":"w-34b414","errorCode":null,"errorMessage":"构建请求失败: %w","messagePattern":"构建请求失败: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"server/mcp/http_client.go","lineNumber":114,"sourceCode":"\ttimeout := global.GVA_CONFIG.MCP.RequestTimeout\n\tif timeout <= 0 {\n\t\ttimeout = 15\n\t}\n\treturn time.Duration(timeout) * time.Second\n}\n\n// defaultUpstreamTimeout 是回打主服务公共(免鉴权)接口的默认超时。\nconst defaultUpstreamTimeout = 10 * time.Second\n\n// fetchPublicUpstream 回打主服务的公共(免鉴权)接口:带超时的 GET + 标准信封解析。\n// 动态 tool 与编排 prompt 的注册共用同一模式,T 为信封 Data 字段的具体负载类型。\nfunc fetchPublicUpstream[T any](path string) (*upstreamEnvelope[T], error) {\n\ttimeoutCtx, cancel := context.WithTimeout(context.Background(), defaultUpstreamTimeout)\n\tdefer cancel()\n\n\treq, err := http.NewRequestWithContext(timeoutCtx, http.MethodGet, upstreamURL(path), nil)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"构建请求失败: %w\", err)\n\t}\n\treq.Header.Set(\"Accept\", \"application/json\")\n\n\tresp, err := http.DefaultClient.Do(req)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"请求上游接口失败: %w\", err)\n\t}\n\tdefer resp.Body.Close()\n\n\trawBody, err := io.ReadAll(resp.Body)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"读取响应失败: %w\", err)\n\t}\n\tif resp.StatusCode >= http.StatusBadRequest {\n\t\treturn nil, fmt.Errorf(\"上游接口返回状态码 %d: %s\", resp.StatusCode, string(rawBody))\n\t}\n\n\tvar result upstreamEnvelope[T]","sourceCodeStart":96,"sourceCodeEnd":132,"githubUrl":"https://github.com/flipped-aurora/gin-vue-admin/blob/3136500ef380842b0eb6c4daa87c3f8a47fcf9e0/server/mcp/http_client.go#L96-L132","documentation":"fetchPublicUpstream is a generic helper that GETs a public upstream endpoint with a timeout. This error wraps http.NewRequestWithContext failures — the HTTP request object could not be constructed, almost always because the final URL (upstreamURL(path)) is malformed (bad scheme, control characters, unparseable host).","triggerScenarios":"Calling any MCP tool that hits the public upstream while the configured upstream base URL is empty or invalid, or path concatenation yields an unparseable URL (spaces, newline, missing scheme).","commonSituations":"Missing/typo'd upstream base in config producing 'http://:8080/...' or relative URL; config value carrying whitespace or BOM; path containing unescaped characters.","solutions":["Inspect upstreamURL(path) — log the final URL and verify it parses (url.Parse succeeds) and has an absolute http/https scheme","Fix the upstream base URL in the server config (no stray spaces, correct scheme/host)","Sanitize/encode the path segment before calling fetchPublicUpstream"],"exampleFix":"// before\nupstreamBase := cfg.UpstreamBase // \"localhost:9999\" (no scheme)\n// after\nupstreamBase := \"http://localhost:9999\" // absolute URL with scheme","handlingStrategy":"validation","validationCode":"u, err := url.Parse(upstreamURL(path))\nif err != nil || u.Scheme == \"\" || u.Host == \"\" {\n  return fmt.Errorf(\"invalid upstream URL %q\", u)\n}","typeGuard":"func isValidUpstreamURL(raw string) bool {\n  u, err := url.Parse(raw)\n  return err == nil && (u.Scheme == \"http\" || u.Scheme == \"https\") && u.Host != \"\"\n}","tryCatchPattern":"req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)\nif err != nil {\n  return nil, fmt.Errorf(\"build request failed: %w\", err)\n}","preventionTips":["Keep the upstream base URL in config as an absolute http(s) URL","Trim whitespace/BOM from config values before building URLs","url.Parse the composed URL once at startup as a smoke check"],"tags":["http","url","network","config"],"backgroundTag":"invalid-url","analyzedSha":"3136500ef380842b0eb6c4daa87c3f8a47fcf9e0","analyzedAt":"2026-08-31T13:50:02.721Z","schemaVersion":2},"datasetVersion":"2026-08-31T19:17:28.585Z"}