How to split modules in multiple deb packages

[Simone Rossetto]

Hello everybody, I'm packaging a daemon that I've developed in python3 and I
need to split the core modules in two deb packages, but I don't now how to do
that.

One of the module is specific for Raspberry Pi, it adds some
functionalities, but
the daemon itself doesn't require a Pi hardware and can still do its job
without that module even on a Pi. What I want to do is to split the modules
in two deb packages, one with all the modules except rpi.py and one with only
rpi.py (setting the appropriate dependencies, i.e. python3-gpiozero, etc).

How can I do that?

I can exclude rpi.py module from main package and create a
python3-mypackage.rpi.install
file installing rpi.py in /usr/lib/python3/mypackage but I don't think it is
the right way of doing that.


This is the source folder:
 mydaemon/
 |-- bin/
 |   `-- mydaemon*
 |
 |-- debian/
 |   |-- changelog
 |   |-- [...]
 |   |-- mydaemon.install
 |   |-- mydaemon.service
 |   |-- python3-mypackage-doc.install
 |   |-- rules*
 |   `-- [...]
 |
 |-- MANIFEST.in
 |-- mypackage/
 |   |-- module1.py
 |   |-- module2.py
 |   |-- moduleN.py
 |   `-- rpi.py
 |
 `-- setup.py

The setup.py file is almost this:
 > setup(name='mydaemon',
 >   packages=['mypackage'],
 >   scripts=['bin/mydaemon'],
 >   install_requires=['python-daemon','jsonschema'])

The MANIFEST.in
 > include setup.py
 > include MANIFEST.in
 > recursive-include mypackage *.py
 > include bin/mydaemon

The debian/rules file contains:
 > dh $@ --with python3,systemd --buildsystem=pybuild


Thanks, bye
Simone

Re: How to split modules in multiple deb packages

[Simone Rossetto]

Hi Dominik, thanks for your reply.

> Well, in that case, with you being upstream, I'd separate the two
> packages entirely.

Yes, I can do that. But, don't you think a whole package for a single
python file is... too much?

>> I can exclude rpi.py module from main package and create a
>> python3-mypackage.rpi.install
>> file installing rpi.py in /usr/lib/python3/mypackage but I don't think it is
>> the right way of doing that.
>
> Why not?

Because I'll miss all the "egg"-related files. Won't I?
And, how can I choose the right destination folder? /usr/lib/python3
or /usr/lib/python3.4 perhaps?

> This is not a Python package.
>
> (Hint: no __init__.py…)

Of course there is a __init__.py file with all the required import
inside mypackage/ folder. I forgot to mention.

>> The MANIFEST.in
>>  > include setup.py
>>  > include MANIFEST.in
>>  > recursive-include mypackage *.py
>>  > include bin/mydaemon
>
> Uh? All of this is duplicating setup.py. Just remove it.

Ok, you are right.

> Instead, please
> make sure to include your full licence, readme and changelog in the
> source tarball from within MANIFEST.in.

Yes yes, the whole file include README.md, COPYING, CHANGELOG and a
samples folder.


Thanks, bye
Simone

Re: How to split modules in multiple deb packages

[Simone Rossetto]

Hi Piotr,

> ("mypackage" is module name which will be shipped in python3-mypackage
> binary package and "rpi" or "rpi-daemon" is binary package shipping the 
> daemon)
> [...]
> if it's one file only (without private modules) you can install directly
> into /usr/bin/

The file rpi.py is a module of mypackage, not the binary of the
daemon. The binary will be installed in its own package that requires
python3-mypackage.


Bye
Simone

Re: How to split modules in multiple deb packages

[Simone Rossetto]

Hi Ioannes,

> why would you want to do that?
> i mean: what harm comes from shipping the rpi.py file on non-rpi systems?

Because only the rpi module requires gpiozero module to work properly,
but I cannot put a dependency on gpiozero for the whole package.

> is that file exposed to the user or is it just internally used?

Exposed to the user.

> is the system failing gracefully if it is there but not really usable,
> because you are missing hardware? (if so, there is no need to split).

Yes, it raises ImportError if the user tries to use a class that needs gpiozero.

> is the system failing gracefully if it is missing on systems that would
> normally use it? (if not, then splitting could actually be harmful).

Yes, same as above. But the user can complain that he/she installed a
package that requires gpiozero without having pyhton3-gpiozero in the
required list...


Bye
Simone