{"record":{"id":"d8d749baba3d25ab","repo":"flipped-aurora/gin-vue-admin","slug":"w-d8d749","errorCode":null,"errorMessage":"请求上游服务失败: %w","messagePattern":"请求上游服务失败: %w","errorType":"http","errorClass":null,"httpStatus":null,"severity":"error","filePath":"server/mcp/http_client.go","lineNumber":203,"sourceCode":"\n\ttimeoutCtx, cancel := context.WithTimeout(ctx, requestTimeout())\n\tdefer cancel()\n\n\treq, err := http.NewRequestWithContext(timeoutCtx, method, requestURL.String(), reader)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"创建上游请求失败: %w\", err)\n\t}\n\treq.Header.Set(\"Accept\", \"application/json\")\n\treq.Header.Set(upstreamAuthHeader, token)\n\tif body != nil {\n\t\treq.Header.Set(\"Content-Type\", \"application/json\")\n\t}\n\t// 链路传播:外部 AI → MCP 进程 → GVA 主服务串成同一条 trace\n\tlogger.InjectTraceHeaders(timeoutCtx, req)\n\n\tresp, err := http.DefaultClient.Do(req)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"请求上游服务失败: %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(\"读取上游响应失败: %w\", err)\n\t}\n\n\tvar result upstreamEnvelope[T]\n\tif len(rawBody) > 0 {\n\t\tif err := json.Unmarshal(rawBody, &result); err != nil {\n\t\t\t// 上游返回非 JSON(如 404/502 的 HTML 或网关错误页):先暴露真实状态码,\n\t\t\t// 不让解析错误掩盖真实的 HTTP 失败\n\t\t\tif resp.StatusCode >= http.StatusBadRequest {\n\t\t\t\treturn nil, fmt.Errorf(\"上游请求失败，状态码: %d，响应: %s\", resp.StatusCode, truncateUpstreamBody(rawBody))\n\t\t\t}\n\t\t\treturn nil, fmt.Errorf(\"解析上游响应失败: %w\", err)\n\t\t}","sourceCodeStart":185,"sourceCodeEnd":221,"githubUrl":"https://github.com/flipped-aurora/gin-vue-admin/blob/3136500ef380842b0eb6c4daa87c3f8a47fcf9e0/server/mcp/http_client.go#L185-L221","documentation":"http.DefaultClient.Do returned a transport-level error (connection refused, DNS failure, TLS error, timeout via the request context); it is wrapped as '请求上游服务失败'. The request never received an HTTP response, so the problem is network/connectivity, not the upstream's answer.","triggerScenarios":"GVA main service not running or listening on a different port than upstreamBaseURL; firewall/security group blocking; DNS name unresolvable; requestTimeout() elapsed before a response; TLS certificate problems on https base URLs.","commonSituations":"Dev environment where the backend port changed; upstreamBaseURL pointing to localhost from inside a container (should use host.docker.internal/service name); server overloaded and exceeding the timeout; VPN/proxy required for the upstream address.","solutions":["Check the wrapped error: 'connection refused' → upstream down/wrong port; 'no such host' → DNS; 'context deadline exceeded' → timeout","Confirm the GVA server is running and listening at the host:port in upstreamBaseURL","curl the same base URL from the MCP process's network position to reproduce","If it is a timeout, raise requestTimeout() or optimize the slow upstream endpoint","In containers, fix the base URL to the service hostname instead of localhost"],"exampleFix":null,"handlingStrategy":"retry","validationCode":"func upstreamAlive(ctx context.Context, base string) error {\n\tc, cancel := context.WithTimeout(ctx, 3*time.Second)\n\tdefer cancel()\n\treq, _ := http.NewRequestWithContext(c, http.MethodGet, strings.TrimRight(base, \"/\")+\"/health\", nil)\n\tresp, err := http.DefaultClient.Do(req)\n\tif err != nil {\n\t\treturn err\n\t}\n\tresp.Body.Close()\n\treturn nil\n}","typeGuard":null,"tryCatchPattern":"result, err := getUpstream[Data](ctx, \"/api/x\", nil)\nif err != nil {\n\tif strings.Contains(err.Error(), \"请求上游服务失败\") {\n\t\t// classify: refused → down, no such host → DNS, deadline exceeded → timeout\n\t\t// apply bounded retry with backoff for transient cases\n\t}\n\treturn err\n}","preventionTips":["Confirm the GVA server is running before starting the MCP process","Use the correct container-internal hostname, not localhost, when sandboxed","Set requestTimeout() generously for known-slow endpoints","Add health-check startup gating so tools fail fast with a clear message","Monitor DNS/TLS changes in the deployment environment"],"tags":["network","http-client","timeout","go"],"backgroundTag":"connection-refused","analyzedSha":"3136500ef380842b0eb6c4daa87c3f8a47fcf9e0","analyzedAt":"2026-08-31T13:50:02.721Z","schemaVersion":2},"datasetVersion":"2026-08-31T22:30:34.772Z"}