dkms mkdeb: post_install scripts are always non-executable

[martingalvan]

Every time I try to use a POST_INSTALL script, I get the following:

Warning: The post_install script is not executable.

This is because of this.

[plouj]

The error would be more helpful if it included the value of $run. The actual issue often is not that the script is not executable but that it doesn't exist at all since dkms does a simple -x test, which means FILE exists and execute (or search) permission is granted. Simply placing the post_install script into the correct sub-directory in /var/lib/dkms/$module/$module_version/source or just /usr/src/$module fixes the problem for me.

[martingalvan]

Almost a year later and this issue still exists.

[WowVeryLogin]

Yeap, having the same issue. Executable bit is just droped from the script file.

[martingalvan]

Almost three years later and the issue is still there.

[scaronni]

Anyone with a simple patch I can merge? I'm not a Debian user, but I can help. Pretty sure that in 3 years people have applied workarounds that we can reuse here.
A patch would close #53 and #55.

[scaronni]

Distribution specific packaging was severely broken for most distributions and has been dropped in the latest release.

[gourryinverse]

@scaronni can you tell us what we're supposed to be doing instead?

[Bassem-Ramzy]

For the record, it runs with me now on dkms 2.8, Ubuntu 20.04.1 LTS, 5.15.0-56-generic.
I get the same error when I set POST_INSTALL="myscript.sh arg1", and worked when set to POST_INSTALL="myscript.sh" (without spaces and arguments), AND more importantly, made sure of the bash script mode chmod u+x myscript.sh.

Also, make sure that when you update your original code/scripts, you manually delete the folder that was previously created on /usr/src (e.g. when previously called dkms add or dkms install), as dkms remove --all sometimes doesn't delete it, and further dkms add/install calls don't update the code. Check code.

[farzadpanahi]

I think I know where the root cause of this issue is.

Problem

dkms mkdeb is using template-dkms-mkdeb template files. You can see that at this line permissions are set to 644 for all files. This will remove x permission for all files including script files:

install -d "$(SRC)"
cp -a $(NAME)-$(VERSION) $(SRC)
chmod 644 -R "$(SRC)/$(NAME)-$(VERSION)"

This Makefile is located under /etc/dkms/template-dkms-mkdeb/ in my system.
Note: Looks like that this file is not maintained by dell/dkms repo anymore. I do not know which package is installing that file.

As mentioned in the manual, dkms uses this file by default:

It uses a template debian directory found in /etc/dkms/template-dkms-mkdeb as the basis for the package.

But we can also define our own Makefile for our own module:

Alternatively, if DKMS finds a file called /usr/src/-/-dkms-mkdeb it will use that folder instead.

Workaround

I copied the template files to my module:

cp -r /etc/dkms/template-dkms-mkdeb /usr/src/<moudle>-<module-version>/<module>-dkms-mkdeb`

Then modified the /usr/src/<moudle>-<module-version>/<module>-dkms-mkdeb/Makefile like this:

#/usr/bin/make
SRC = $(DESTDIR)/usr/src
SHARE = $(DESTDIR)/usr/share/$(NAME)-dkms

all:

clean:

install:

#source tree
ifeq ("$(wildcard $(NAME)-$(VERSION))", "$(NAME)-$(VERSION)")
	install -d "$(SRC)"
	cp -a $(NAME)-$(VERSION) $(SRC)
	#chmod 644 -R "$(SRC)/$(NAME)-$(VERSION)"
endif

#tarball, possibly with binaries
ifeq ("$(wildcard $(NAME)-$(VERSION).dkms.tar.gz)", "$(NAME)-$(VERSION).dkms.tar.gz")
	install -d "$(SHARE)"
	install -m 644 $(NAME)-$(VERSION).dkms.tar.gz "$(SHARE)"
endif

#postinst, only if we are supporting legacy mode
ifeq ("$(wildcard common.postinst)", "common.postinst")
	install -d "$(SHARE)"
	install -m 755 $(PREFIX)/usr/lib/dkms/common.postinst $(SHARE)/postinst
endif

Basically only commented this line:

#chmod 644 -R "$(SRC)/$(NAME)-$(VERSION)"

Since the Makefile is using cp -a to copy all the files then file permissions will be preserved. I just need to make sure my scripts have the right x permissions sitting at the root of my module /usr/src/<module>-<module-version>/ :

-rwxr-xr-x 1 pi pi 276 Jun 12 15:42 post-install.sh
-rwxr-xr-x 1 pi pi 228 Jun 12 15:38 post-uninstall.sh

My dkms.conf has these lines:

POST_INSTALL="post-install.sh"
POST_REMOVE="post-uninstall.sh"

Doing these steps, dkms mkdeb will use the Makefile in my module's template to create .deb file properly with correct permissions and when I install .deb file the scripts do run fine with no error.

Good thing about this workaround is that I don't need to touch /etc/dkms/template-dkms-mkdeb/Makefile and I can leave it as is, and I can just craft a custom Makefile for my module without affecting other modules.

Moving Forward

My workaround may work for some other people as well, but I think the proper solution is to fix /etc/dkms/template-dkms-mkdeb/, so that everyone can use dkms mkdeb with scripts with no problem.

Let me know if you know where /etc/dkms/template-dkms-mkdeb/ is maintained, I will try to send a PR!

[evelikov]

Let me know if you know where /etc/dkms/template-dkms-mkdeb/ is maintained, I will try to send a PR!

@farzadpanahi as mentioned above distro specifics have been dropped from dkms itself. It's possible that Debian and/or Ubuntu has a copy/variant of it, but for that you'll have to check with their gitlab instance