I've tried many approaches until I was successful.
The approach that worked
The only approach that worked was downloading the deb-bundble.tar from MySQL website and installing the packages one by one. I followed these steps:
- Go to MySQL 5.6 download page: https://dev.mysql.com/downloads/mysql/5.6.html#downloads
- In the OS options, select "Ubuntu 14.04 64-bit"
- Download the deb-bundle, a file named:
mysql-server_5.6.40-1ubuntu14.04_amd64.deb-bundle.tar, usually, it's the first option
- Untar the bundle somewhere using:
tar -xf mysql-server_5.6.40-1ubuntu14.04_amd64.deb-bundle.tar
- The tar contains multiple
deb packages, including
mysql-community-server, ... etc
- Then I tried to install these using:
sudo dpkg -i <package-name> one-by-one, but I had follow their order according to error messages that fired, e.g.: I first tried:
sudo dpkg -i mysql-server_5.6.40-1ubuntu14.04_amd64.deb, it failed because it requires
mysql-community-server_5.6.40-1ubuntu14.04_amd64.deb to be installed first and so on
- Some of the package installed successfully, some produced errors, after I have tried
sudo dpkg -i mysql-server_5.6.40-1ubuntu14.04_amd64.deb for the last time which gave some errors, I desperately tried:
sudo apt-get install -f which grabbed the missing dependencies and voila, MySQL Server 5.6 is successfully installed, up and running
Approaches that didn't work
Using Trusty Universal Repo
It's worth mentioning that I first tried the same approach that used to work in Ubuntu 16.04, that is, to add the 'trusty universe' repo and try installing mysql-server-5.6, i.e. I followed this:
sudo add-apt-repository 'deb http://archive.ubuntu.com/ubuntu trusty universe'
sudo apt-get update
apt-get install mysql-server-5.6
This approach did NOT work. It failed because there's a dependency
initscripts that cannot be installed. It seems that it have been replaced after Ubuntu 16.04. Installing it's replacements:
util-util-linux sysvinit-utils didn't help either.
Using MySQL apt config package
I also tried using MySQL config package (
mysql-apt-config_0.7.3-1_all.deb) I downloaded from this repo: https://repo.mysql.com/ and installed via:
sudo dpkg -i mysql-apt-config_0.7.3-1_all.deb. It didn't recognize Ubuntu 18.04 (bionic) of course, so, I acted as if it's xenial and configured MySQL Server version to 5.6, then I tried to check which MySQL version is now available for installation using:
apt-cache policy mysql-server but that also didn't work, I still have later versions than 5.6.
Although the last two approaches didn't work, they may have contributed to the success of the first approach by making some packages or configuration available, I honestly don't know.
When I became hopeless that any approach would work, I considered compiling and installing it from source, I started that endeavor (I installed the build essentials and created the user group and the user) and was about to grab the source code when I stumbled upon the deb-bundle that turned out to be fruitful and was the successful approach I described above.