今天在Ubuntu 14.04上安装docker时遇到一个代理的问题 ，出错如下：
sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --homedir /tmp/tmp.poBpYdk3bZ --no-auto-check-trustdb --trust-model always --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyring /etc/apt/trusted.gpg.d/hewlett-packard.gpg --keyring /etc/apt/trusted.gpg.d/hp_2014.gpg --keyring /etc/apt/trusted.gpg.d/hp_a2014.gpg --keyring /etc/apt/trusted.gpg.d/hp_b2014.gpg --keyring /etc/apt/trusted.gpg.d/mibtools.gpg --keyring /etc/apt/trusted.gpg.d/oracle_vbox.gpg --keyring /etc/apt/trusted.gpg.d/ppa_chrome-b.gpg --keyring /etc/apt/trusted.gpg.d/ppa_chrome.gpg --keyring /etc/apt/trusted.gpg.d/ppa_firefox.gpg --keyring /etc/apt/trusted.gpg.d/ppa_java.gpg --keyring /etc/apt/trusted.gpg.d/ppa_openjdk.gpg --keyring /etc/apt/trusted.gpg.d/ppa_s1.gpg --keyring /etc/apt/trusted.gpg.d/ppa_virtualbox.gpg --keyring /etc/apt/trusted.gpg.d/semc-packetsigner.gpg --keyring /etc/apt/trusted.gpg.d/swerepo.gpg --keyring /etc/apt/trusted.gpg.d/ubuntuclient.gpg --keyring /etc/apt/trusted.gpg.d/webupd8.gpg --keyserver-options http-proxy=proxy.global.sonyericsson.net:8080 --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D gpg: requesting key 2C52609D from hkp server p80.pool.sks-keyservers.net ?: invalid HTTP proxy (): unsupported URI gpgkeys: HTTP fetch error 7: couldn't connect: Success gpg: no valid OpenPGP data found. gpg: Total number processed: 0
刚开始我一直是手动设置的代理如：
export http_proxy=proxyserver:port export https_proxy=proxyserver:port
但还是报这个错，然后Google了一下，发现加了以下标黄的代码就解决了：
"--keyserver-options http-proxy=http://username:password@proxyserver:port"
sudo apt-key adv --keyserver-options http-proxy=http://username:password@proxyserver:port --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D