我正在尝试在 Ubuntu 16.04 服务器上安装 mysql 5.6。我知道 mysql 可用的软件包是 5.7 版，但为了安装 5.6，我执行了以下步骤
RUN rm -rf /var/lib/apt/lists/*
RUN apt-get update -y
RUN apt-get upgrade --fix-missing -y
RUN apt-get clean
RUN apt-get install software-properties-common -y
RUN add-apt-repository 'deb http://archive.ubuntu.com/ubuntu trusty universe'
RUN apt install mysql-client-5.6 -y
这仍然会出现以下错误
137958 [INFO] Package mysql-client-5.6 is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source
However the following packages replace it:
mysql-testsuite-5.7 mariadb-server-core-10.0 mariadb-client-10.0
mysql-server-core-5.7 mysql-client-5.7
137963 [INFO] [91mE: Package 'mysql-client-5.6' has no installation candidate
从哪个存储库进行安装才是正确的？