现象：本地环境调试，可以获取图片资源的buffer。上传到正式环境，获取不到数据，且无异常信息。云函数设置超时时间都是20s；

相关代码：
// 传入一个小程序云存储的path，返回图片对应的资源id
const getImgMediaId = async function (imgPath) {
  // 下载图片
  const fileID = `${cloudFilePrefix}${imgPath}`
  let finalRes = {}
  let downFileRes = {}
  console.log("fileID", fileID)
  try {
     downFileRes = await cloud.downloadFile({
      fileID: fileID
    })
    console.log("downFileRes", downFileRes)
  } catch (e) {
    console.log(111, e)
  }
  try {
    // 上传图片
    finalRes = await cloud.openapi.customerServiceMessage.uploadTempMedia({
      type: 'image',
      media: {
        contentType: 'image/jpeg',
        value: file
      }
    })
  } catch (e) {
    console.log(222, e)
  }
  return finalRes
}

云函数日志：
返回结果

null

日志
START RequestId: f9903ccb-78b0-11ea-993b-525400090c2c
Event RequestId: f9903ccb-78b0-11ea-993b-525400090c2c
2020-04-07T09:20:09.668Z  fileID cloud://xxxxxx/server/serviceTeacherErcode/tearcher_code_1.jpg
END RequestId: f9903ccb-78b0-11ea-993b-525400090c2c
Report RequestId: f9903ccb-78b0-11ea-993b-525400090c2c Duration:103ms Memory:256MB MemUsage:35.730469MB