Why installing openjdk-7-jdk on Ubuntu Trusty installs systemd as well?

[Colin Law]

On 3 January 2017 at 19:55, sktsee <sktseer at gmail.com> wrote:
> On Tue, 03 Jan 2017 12:09:37 +0200, Yuri Kanivetsky wrote:
>
>> In lxc containers you usually get pretty basic set of packages. For
>> example, in Ubuntu Trusty man and curl packages are not "preinstalled".
>> In other distributions there was no less and ping right away, AFAIR.
>>
>> And AFAIU, lxc containers use kernel of the host machine. It's not that
>> I see how it can affect installing openjdk in the guest. But it makes
>> sense to check it with Virtualbox, after all. What I'm planning to do
>> one of these days.
>
> It's probably being pulled in as :Recommends dependency. If you specify
> "--no-install-recommends" with apt-get, it'll might leave systemd off. Of
> course, it will leave other recommended packages that you may want to be
> installed off as well. You'll just need to compare the output from the
> two simulated apt commands.
>
> See what the following does:
>
> $ sudo apt-get -s install --no-install-recommends openjdk-7-jdk
>
> Also, if it looks like systemd is going to be installed regardless of the
> no-install-recommends option (some os components like udev rely on systemd
> functions), you could install the package systemd-shim to provide systemd
> functionality for systemd services without using it as the init service.

What is not explained is why on my 14.04 system it does not try to
install systemd, but on this one it does.

Colin