Dev/About Debian Packaging

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Recommends vs Depends[edit]

This is about Recommends: vs Depends: in context of debian/control.

debian/control: There are separate meta packages for dependencies and recommended packages. For example:

  • anon-shared-packages-dependencies
  • anon-shared-packages-recommended

The reason for this is, because if we used the Recommends: field for Whonix ™ meta packages (those who pull the required Debian upstream packages for creating Whonix ™), we could not install them using apt with --install-recommends, which is apt's default option, because that would also install packages recommend by any dependency we install.

On the other hand, if we installed using apt --no-install-recommends, the packages Whonix ™ meta packages recommends, will not get installed.

Therefore splitting them into packages suffixed *-dependencies or *-recommended which both use Depends: and installing them using --no-install-recommends appeared to be the only solution.

Otherwise it would install packages such as virtuoso, soprano and vlc, which are not useful in context of Whonix-Gateway ™.

The Recommends: and Suggests: field is still being used but this is mostly useful for one package advertising related packages users using apt-cache show package-name and Packages for Debian Hosts.

See also Debian_Packages#Technical_Information.

Files in Home Folder[edit]

Packages placing files /home folder must use the correct mechanism for doing so. Using defined mechanisms (see below) might be appropriate. Directly writing /home is prohibited for reasons listed below.

Files in /etc/skel[edit]

  • Files in /etc/skel are not as bad as files in /home folder.
    • Works for any user.
  • Inconsistencies. Not deployed through /etc/skel mechanism if file is added to a package after a user account was created. I.e. users who upgraded will miss that file.
    • Needs special code to handle such cases.
  • If the file from /etc/skel is in the user's home folder, it's hard to update it. Updating the file in /etc/skel won't effect the user's version of the file in the user's home folder.
    • Needs special code to handle such cases.

Modifying Default Configuration of Third Party Packages[edit]

Taking systemd as an example. Suppose /lib/systemd/system/systemd-random-seed.service modifications are desired.

File /lib/systemd/system/systemd-random-seed.service is owned by a third party package systemd.

dpkg -S /lib/systemd/system/systemd-random-seed.service

systemd: /lib/systemd/system/systemd-random-seed.service
  • Editing /lib/systemd/system/systemd-random-seed.service.
    • Is the worst (changes get lost on systemd package gets upgraded) (there is a solution using dpkg-divert encapsulated in a more sane by using config-package-dev displace and we use it in Whonix ™ source code where it could not be avoided but if avoidable it is best avoided if possible somehow).
  • Shipping /etc/systemd/system/systemd-random-seed.service
    • would be better but still not great (this is for local administrator, not linux distribution)
  • /lib/systemd/system/systemd-random-seed.service.d folder and a file such as /lib/systemd/system/systemd-random-seed.service.d/30_something.conf
    • is an ideal solution for linux distributions such as Whonix since it does not takeover files by other packages and does not take away something from the local system administrator or user.

config-package-dev[edit]

Debian package xfce4-session owns file /etc/xdg/xfce4/xfconf/xfce-perchannel-xml/xfce4-session.xml. Therefore package whonix-xfce-desktop-config cannot directly overwrite it.

Preparing to unpack .../whonix-xfce-desktop-config_1.4-1_all.deb ...
Unpacking whonix-xfce-desktop-config (3:1.4-1) ...
dpkg: error processing archive /mnt/initialdeb/pool/main/w/whonix-xfce-desktop-config/whonix-xfce-desktop-config_1.4-1_all.deb (--unpack):
 trying to overwrite '\''/etc/xdg/xfce4/xfconf/xfce-perchannel-xml/xfce4-session.xml'\'', which is also in package xfce4-session 4.12.1-6
Errors were encountered while processing:
 /mnt/initialdeb/pool/main/w/whonix-xfce-desktop-config/whonix-xfce-desktop-config_1.4-1_all.deb
E: Sub-process /usr/bin/dpkg returned an error code (1)       '
+ apt_get_exit_code=100

config-package-dev can help with such situations.

Examples on how to use config-package-dev displace:

Ideally avoided as per above.

https://debathena.mit.edu/config-packages/

Desktop Environment (Xfce) Settings Changes[edit]

Testing modified desktop environment (Xfce) settings files in /etc/skel or /home/user is cumbersome.

When Xfce is shutdown, it might undo the manual or package modified settings in user home folder /home/user as part of Xfce "save settings" procedure on shutdown. Therefore after reboot these settings might be reverted and could not be actually tested.

A script which is supposed to be run from a virtual console to simplify the steps:

/usr/libexec/helper-scripts/desktop-background-skel-test

Whonix / Kicksecure ™ Package Design[edit]

  • whonix-base-files: Whonix-Host, Whonix-Gateway, Whonix-Workstation
  • whonix-libvirt: Whonix-Host only
  • anon-gw-base-files: Whonix-Gateway only
  • anon-ws-base-files: Whonix-Workstation only
  • kicksecure-base-files: Kicksecure-VMs and Kicksecure-Hosts
  • vm-config-dist: Kicksecure-VMs and Whonix-VMs

See Also[edit]