x509: failed to load system roots and no roots provided

x509 error when using HTTPS inside a Docker container

在docker容器中運行服務碰到'x509: failed to load system roots and no roots provided'的錯誤，原因是該服務用到了HTTPS協議，而容器裡面沒有相應的環境，用以下方法解決

[code]RUN apt-get update  
RUN apt-get install -y ca-certificates