You can see the history of what you've installed via
```bash
$ grep apt-get.install history.log 
Commandline: apt-get install -y openssh-server ubuntu-server mariadb-client mariadb-server apache2 libapache2-mod-php tmux vim g++ python3-pip python-is-python3 rsync
Commandline: apt-get install -y gh
Commandline: apt-get install -y xsel
Commandline: apt-get install -y ffmpeg
```