lesson-curl-request-troubleshoot.json

{
  "task_id": "lesson-curl-request-troubleshoot",
  "title": "curl / wget 请求失败通用排查",
  "domain": "devops",
  "tags": [
    "network",
    "curl",
    "wget",
    "debug",
    "troubleshoot"
  ],
  "problem": "`curl https://example.com` 返回空、报错或超时。不知道是 DNS、代理、证书还是目标服务的问题。",
  "solution": "```bash\n# 1. DNS 解析\nnslookup example.com\ndig example.com\n# 正常返回 IP 地址 → DNS OK\n# 返回 NXDOMAIN / server can't find → DNS 问题\n\n# 2. 网络连通性（跳过代理）\ncurl -v --noproxy \"*\" https://example.com\n# 能连接但超时 → 防火墙/代理问题\n\n# 3. 证书验证\ncurl -v https://example.com\n# SSL certificate problem → 证书问题\n# 临时跳过（仅测试）：\ncurl -k https://example.com\n\n# 4. 代理验证\necho $http_proxy\necho $https_proxy\n# 查看当前代理配置\n\n# 5. 指定超时（默认无超时）\ncurl --connect-timeout 5 --max-time 10 https://example.com\n\n# 6. 只看响应头（不下载内容）\ncurl -I https://example.com\n\n# 7. 完整的排查命令\ncurl -v --trace-ascii /dev/stderr https://example.com 2>&1 | head -30\n```",
  "source": "lessons/contrib/curl-request-troubleshoot.md",
  "test_cmd": ""
}