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Re: [school-discuss] need help with custom Linux installation CD or DVD

Sorry. Maybe I've not clearly exposed my message.

On 14/01/2018 16:30, LM wrote:
> [...]
> I actually like updating Debian this way better than doing an update
> or upgrade while connected to the Internet.
> [...]

That's _NOT_ what I was suggesting, nor what apt-mirror is for.

Let me try with an example.

If you're planning to setup a new laboratory with 20 clients in central
Africa, _DISCONNECTED_ from the Internet, and want to offer courses about,
for example, TuxPaint + Libreoffice + apache+PHP than _BEFORE_LEAVING_ you can:

a) setup a new debian-box; install your required packages; "image"/"copy"
your installed debian so to be copied 20 times, once for each PCs in the
rural lab;


b) launch "apt-mirror" on your very PC and create an "apt-mirror archive"
(on your PC). Copy such archive to a flash-drive, and add to such a drive
an ISO of your preferred debian distribution.
Then, when in Africa, install a "master" debian box and copy the mirrored
apt-mirror folder "back" on local disk. Then, you can launch a net-install
of the 20 clients, pointing them to local repository on the master node
(this is an added benefit).

If you follow approach a) you have a problem: as soon as you're in Africa
and... suddenly discover that you are no-more interested in PHP but, insted
you need also PERL and PYTHON, as well as a bit of NodeJS (and maybe LaTeX
or R or whatever else), you're OUT! You cannot install such packages as...
they're nowhere! :-(
You have no other choice than.... download, maybe via some (very expensive)
satellite connection.

If you follow approach b), you can simply "apt-get install nodejs" as....
the package is there! Inside your "Debian Repository mirror"... that you
just copied on your "master" PC (as it was apt-mirrored).
So, with a full-mirror, you  _ALWAYS_ have the freedom to install whatever
you want, providing it's packaged inside the debian repository.
Specifically, you don't need to choose, ex-ante, what you're going to use
when you'll be off-line.

Please note that I'm deliberately _NOT_ talking about "updates". You
definitely _NOT_ need to update anything! And, BTW, as you're disconnected
from the Internet you even don't need to deal with security updates! You
can work 100% _OFFLINE_ (while in Africa).

_BUT_ as soon as you discover that your childs are getting.... eager to
learn the very latest about javascript technologies and, for this, you need
the very latest version of "nodejs" than... you can simply run "apt-mirror"
(to "update" the mirror; this require an Internet connection) on the
"master PC" (the one hosting the repository) and... rightafter, every other
20 PC can run "apt-get update" to receive the updates (even if they're

> I feel like I have more
> control over the packages that get installed (especially the
> dependencies).

Uhm... I think it's not going to work this way. Package manager shoud be
"trusted" by default. So if a package manager say: "I need to install
dependency X", you need to accept such a decision as there are _VERY_GOOD_
reasons for such a requiements. And unless you're a
debian-official-developer/maintainer... I think it will be "hard" to
understand such a requirement, as it has been the original developer that,
while "packaging" his own application, decided which other packages are
required by "his" application.

Let me put in another way: you are free to handle file copies out of the
package-manager (obviously!) but... chances are high that you'll "brake"
your system or, better, you simply won't be able to run the application you
might need.

> If the package manager needs a dependency I don't want
> in order to get a program I want to run, it just doesn't install the
> program.

Again: it's not going to work this way. When a package "require" a
dependency, than this dependency need to be fulfilled, as it has been a
decision of the original developer.
If you feel that a dependency is "useless", than you should file a "bug" :-)

> Otherwise, if you're not careful and you just let the
> package manager pull whatever it wants from the Internet

Tha package manager does not "pull whatever it wants from the Internet". It
simply assure you that in order to run the application _YOU_ are asking it
to install... it install also the required libraries and components as well.

My 0.02€ :-)


Damiano Verzulli
e-mail: damiano@xxxxxxxxxxx
"Technical people tend to fall into two categories: Specialists
and Generalists. The Specialist learns more and more about a
narrower and narrower field, until he eventually, in the limit,
knows everything about nothing. The Generalist learns less and
less about a wider and wider field, until eventually he knows
nothing about everything." - William Stucke - AfrISPA

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