common.postinst and AUTOINSTALL=""

[anbe42]

If a dkms package does not set AUTOINSTALL=yes in its dkms.conf (yes, we have one such package in Debian, but I don't know whether this omission is intentional... ), what should common.postinst do upon installation?
Should it really build and install the module?

Right now we have inconsistent behavior depending on the installation order:
case a)

1. foo-dkms -> common.postinst finds no headers -> no module built
2. linux-headers-bar -> triggers dkms autoinstall -> no module built due to AUTOINSTALL=""

case b)

1. linux-headers-bar -> no modules installed, none built
2. foo-dkms -> common.postinst finds headers -> module gets built

IMO common.postinst should honor the AUTOINSTALL setting and not try to build and install the module.

[anbe42]

I'll test the following in dkms_common.postinst:

autoinstall=$(AUTOINSTALL=; . "/var/lib/dkms/$NAME/$VERSION/source/dkms.conf" >/dev/null 2>&1; echo $AUTOINSTALL)
if [ -z "$autoinstall" ]; then
    echo "Not building the $NAME module which does not have AUTOINSTALL enabled."
    exit 0
fi

[evelikov]

The current code skips the module if $AUTOINSTALL is empty even if set. Aka:

autoinstall()
{
  ...
  if [[ ! $AUTOINSTALL ]]; then
    continue;
  fi
  ...
}

As mentioned previously I would love us to nuke dkms_common.postinst. In order to have no breaking changes in Debian, it could simply calls to kernel_postinst.d_dkms.in and/or kernel_prerm.d_dkms.

Can I offer some virtual 🍪 to sketch and test how it works from Debian POV? Thanks in advance

[anbe42]

dkms_common.postinst and kernel_postinst.d_dkms.in are two orthogonal things:
dkms_common.postinst runs after installation of foo-dkms and builds the foo module for all kernels
kernel_postinst.d_dkms.in runs after installation of a hernel (or its headers) and builds all modules for this kernel

if dkms_common.postinst is not used elsewhere I have no problem moving it to the debian packaging, but we cannot get rid of it for a few years at least since it is referenced in the maintainer scripts of all *-dkms packages

[evelikov]

dkms_common.postinst is used outside of Debian (+ derivatives) so having it upstream is fine. Although I would love to trim it down, or document at the very least.

Notable bits:

• sources debconf a file - is that still relevant?
• duplicates existing dkms logic - framework.conf, no-autoinstall, kernel-headers ...
• while we request autoinstall_all_kernels we install only on latest one (determined via dpkg, rpm) + current kernel ... seemingly not "all" as per the request
• takes 5 args ... (at a glance) all users provide only 2 + bunch of additional logic for the 3-5 args

I would love to see AUTOINSTALL fixed, but IMHO we should looked into at least some of the above first.

[anbe42]

Ideally this common.postinst functionality ("build $module for all kernels") should be part of dkms (so it could reuse the existing logic) and common.postinst simply calls dkms like kernel_postinst.d_dkms calls dkms autoinstall.

[evelikov]

Fully agreed - it seems like others not using common.postinst (like Arch) will also benefit from such functionality being in core dkms.

Opened a separate task with some details and pointers. Thanks o/