Invoice Ninja

I gave Invoice Ninja a try. I used this installation guide

First Step Failure

root @sol:~# apt-get install php-fpm mysql-server php-cli php-common php-curl php-gd php-mysql php-xml php-mcrypt php-mbstring
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package php-mcrypt 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

Package mysql-server 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

E: Package 'mysql-server' has no installation candidate
E: Package 'php-mcrypt' has no installation candidate

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