使用httr2请求欧盟农业食品API遇SSL_read错误，求解决方案

问题重现 #

使用httr2请求欧盟农业食品局牛肉价格API时遭遇SSL读取错误，代码如下：

library(tidyverse)
library(httr2)

req <- request("https://www.ec.europa.eu/agrifood/api/beef/prices?memberStateCodes=PT&years=2019,2020&months=1,3,9&weeks=5,6,7,8,40,41,42&beginDate=01/09/2019&endDate=02/02/2020&carcassCategories=heifers,cows")

resp <- req |> req_perform()

错误信息：

Error in req_perform():
! Failed to perform HTTP request.
Caused by error in curl::curl_fetch_memory():
! OpenSSL SSL_read: error:0A000126:SSL routines::unexpected eof while reading, errno 0

解决方案 #

• 临时禁用SSL证书验证
  部分情况下服务器证书配置可能存在兼容性问题，可临时关闭证书验证（注意：仅用于测试，生产环境不推荐）：

  library(tidyverse)
  library(httr2)
  
  req <- request("https://www.ec.europa.eu/agrifood/api/beef/prices?memberStateCodes=PT&years=2019,2020&months=1,3,9&weeks=5,6,7,8,40,41,42&beginDate=01/09/2019&endDate=02/02/2020&carcassCategories=heifers,cows") |>
    req_options(ssl_verifypeer = FALSE)
  
  resp <- req |> req_perform()
  

• 更新依赖库
  错误可能源于curl或OpenSSL版本过旧，尝试更新R的curl包及系统级的OpenSSL库：

  install.packages("curl")
  

  系统层面更新方式：Windows可通过Chocolatey安装最新curl，macOS用Homebrew，Linux用对应包管理器（如apt、yum）。

• 添加用户代理头
  部分服务器会拦截无标识的请求，模拟浏览器用户代理可避免被拒绝：

  req <- request("https://www.ec.europa.eu/agrifood/api/beef/prices?memberStateCodes=PT&years=2019,2020&months=1,3,9&weeks=5,6,7,8,40,41,42&beginDate=01/09/2019&endDate=02/02/2020&carcassCategories=heifers,cows") |>
    req_headers(`User-Agent` = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36") |>
    req_options(ssl_verifypeer = FALSE) # 可结合证书禁用
  
  resp <- req |> req_perform()
  

• 修正URL参数格式
  检查API参数是否符合要求，比如日期格式可能需要YYYY-MM-DD而非DD/MM/YYYY，改用req_url_query构建参数更规范：

  req <- request("https://www.ec.europa.eu/agrifood/api/beef/prices") |>
    req_url_query(
      memberStateCodes = "PT",
      years = c("2019", "2020"),
      months = c("1", "3", "9"),
      weeks = c("5", "6", "7", "8", "40", "41", "42"),
      beginDate = "2019-09-01",
      endDate = "2020-02-02",
      carcassCategories = c("heifers", "cows")
    ) |>
    req_options(ssl_verifypeer = FALSE)
  
  resp <- req |> req_perform()
  

内容的提问来源于stack exchange，提问作者NickD