Snap package cannot read fonts conf

SYaslem · April 16, 2020, 10:08am

I started move to Ubuntu 20.04 but when i install chromium form Snap

apt install chromium-browser

Chromium cannot read /etc/fonts/conf.d/65-ubuntu-font-family-arabic.conf that contain

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>Ubuntu</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="strong">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Sans</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Serif</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Serif</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="strong">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <alias>
  	<family>DejaVu Serif</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu Serif</family>
	</prefer>
    </alias>
    <alias>
  	<family>DejaVu Sans</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu Sans</family>
	</prefer>
    </alias>
    <alias>
  	<family>DejaVu</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu</family>
	</prefer>
    </alias>
</fontconfig>

font source: https://launchpad.net/ubuntu/+source/ubuntu-font-family-sources/0.84~mono0.83+arabicfontconfig-0ubuntu1

How i can make snap package read that files?

If you notice, Chromium and Ubuntu Software not use default system fonts
Gedit, Firefox and Files use System fonts correctly
5d7b5d484663304713a92398e6691625f7001617_2_690x335

SYaslem · April 16, 2020, 10:32am

Chromium binary works well
4306285c980d0650fbbec37e2f8596b092629d12_2_690x335

oSoMoN · April 20, 2020, 1:45pm

Sorry for the late feedback @SYaslem.

If you’re willing to re-install the chromium snap to help us diagnose and fix the problem, could you run it and in parallel have the following command running in a separate terminal window:

journalctl -f | grep DEN

Then please share the output here. Thanks in advance!

oSoMoN · April 20, 2020, 1:48pm

(note to self) possibly related thread: Snapped app not loading fonts on Fedora (and Arch)

SYaslem · April 20, 2020, 4:00pm

أبريل 20 18:59:02 syaslem audit[665]: USER_AVC pid=665 uid=100 auid=4294967295 ses=4294967295 msg='apparmor="DENIED" operation="dbus_method_call"  bus="system" path="/" interface="org.freedesktop.DBus.ObjectManager" member="GetManagedObjects" mask="send" name="org.bluez" pid=4077 label="snap.chromium.chromium"
أبريل 20 18:59:02 syaslem kernel: audit: type=1107 audit(1587398342.076:77): pid=665 uid=100 auid=4294967295 ses=4294967295 msg='apparmor="DENIED" operation="dbus_method_call"  bus="system" path="/" interface="org.freedesktop.DBus.ObjectManager" member="GetManagedObjects" mask="send" name="org.bluez" pid=4077 label="snap.chromium.chromium

oSoMoN · April 20, 2020, 4:13pm

Thanks. There is no denial on /etc/fonts/. I’ll see if I can reproduce the bug in a VM.

oSoMoN · April 20, 2020, 4:27pm

Pardon my ignorance, how did you manage to get that font installed in 20.04? It appears it was in xenial only, not available in later versions, and when I download the deb to manually install it, I get a conflict with fonts-ubuntu.

SYaslem · April 20, 2020, 4:43pm

install fonts manual in
/usr/local/share/fonts

then create /etc/fonts/conf.avail/65-ubuntu-font-family-arabic.conf contains

<?xml version="1.0"?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
<fontconfig>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>Ubuntu</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="strong">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Sans</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Serif</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="same">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <match target="pattern">
        <test name="family" compare="eq">
            <string>DejaVu Serif</string>
        </test>
        <test name="lang" compare="contains">
            <string>ar</string>
        </test>
        <edit name="family" mode="assign" binding="strong">
            <string>Ubuntu Arabic</string>
        </edit>
    </match>
    <alias>
  	<family>DejaVu Serif</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu Serif</family>
	</prefer>
    </alias>
    <alias>
  	<family>DejaVu Sans</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu Sans</family>
	</prefer>
    </alias>
    <alias>
  	<family>DejaVu</family>
	<prefer>
	  <family>Ubuntu Arabic</family>
	  <family>DejaVu</family>
	</prefer>
    </alias>
</fontconfig>

and create syslink for it in /etc/fonts/conf.d/

ogra · April 20, 2020, 5:29pm

have you tried putting the font into

~/.local/share/fonts/

might be that snapd’s desktop interface simply does not allow access to /usr/local/share/fonts …

ppd · April 20, 2020, 6:06pm

As per https://gitlab.com/apparmor/apparmor/-/blob/master/profiles/apparmor.d/abstractions/fonts, it should be readable.

ogra · April 20, 2020, 6:19pm

ah i had only checked the snapd source, not the apparmor font abstraction …

github.com

snapcore/snapd/blob/master/interfaces/builtin/desktop.go#L56


# other interfaces (eg, wayland).
#include <abstractions/dbus-strict>
#include <abstractions/dbus-session-strict>
# Allow finding the DBus session bus id (eg, via dbus_bus_get_id())
dbus (send)
     bus=session
     path=/org/freedesktop/DBus
     interface=org.freedesktop.DBus
     member=GetId
     peer=(name=org.freedesktop.DBus, label=unconfined),
#include <abstractions/fonts>
owner @{HOME}/.local/share/fonts/{,**} r,
/var/cache/fontconfig/   r,
/var/cache/fontconfig/** mr,
# some applications are known to mmap fonts
/usr/{,local/}share/fonts/** m,
# subset of gnome abstraction

SYaslem · April 20, 2020, 6:30pm

the issue not read fonts
chromium can found “Ubuntu Arabic” but cannot read conf.d that make it replace to "DejaVu "

SYaslem · April 20, 2020, 6:48pm

%D9%84%D9%82%D8%B7%D8%A9%20%D8%B4%D8%A7%D8%B4%D8%A9%20%D9%85%D9%86%202020-04-20%2021-45-30

oSoMoN · April 22, 2020, 1:18pm

Can you try the following? Edit ~/snap/chromium/current/.config/fontconfig/fonts.conf to add the following line:

<include ignore_missing="yes">/etc/fonts/conf.d</include>

Then save the file and restart chromium.

I’m not really sure what to expect visually, but I can tell that when stracing the snap, adding that line allowed the app to find and read your custom fonts configuration file.

SYaslem · April 22, 2020, 1:36pm

Thank you, that work great!
%D9%84%D9%82%D8%B7%D8%A9%20%D8%B4%D8%A7%D8%B4%D8%A9%20%D9%85%D9%86%202020-04-22%2016-35-01

how i can do it globally?

oSoMoN · April 22, 2020, 2:27pm

@jamesh is this something we should consider for addition to the desktop helpers?

SYaslem · April 22, 2020, 3:00pm

That will be helpful

SYaslem · April 23, 2020, 3:39pm

after restart the changes removed

oSoMoN · April 24, 2020, 12:12pm

Ah, that’s quite unfortunate… Indeed the fontconfig file is regenerated everytime there’s an update (a new revision) to the snap. We need a way for users to define custom configs that stick.

lucyllewy · April 24, 2020, 4:39pm

Create an empty fontconfig-user.conf if it doesn’t exist for <include>? Only touch that file if it doesn’t exist, so that the fontconfig ruleset doesn’t break by it potentially not being present, allowing the user to add their custom rules in this separate non-generated file.