Adjust text scaling factor for all users

Change defaults by editing the original schemas

1. Change default value in Glib schema

    sudo nano /usr/share/glib-2.0/schemas/org.gnome.desktop.interface.gschema.xml
   

   Like:

        <key type="d" name="text-scaling-factor">
        <range min="0.5" max="3.0"/>
        <default>0.7</default>
        <summary>Text scaling factor</summary>
        <description>Factor used to enlarge or reduce text display, without changing font size.</description>
        </key>
   

2. Compile schemas

    sudo glib-compile-schemas /usr/share/glib-2.0/schemas
   

Changing defaults by creating an override file

Otherwise, because you want an easy way for puppet.

1. You can create a dconf override file:

    sudo nano /usr/share/glib-2.0/schemas/30_my-text-factor.gschema.override
   

2. Append override keys & values to it, example:

    [org.gnome.desktop.interface]
    text-scaling-factor=0.7
   

3. Compile schemas

    sudo glib-compile-schemas /usr/share/glib-2.0/schemas
   

The new users and the users uses default (They never changed value or they have reset it) will get the new value effective.

Force all users to use defaults using a lock file

If you want to force users to use default value (their customized value has no effect), add a dconf lock:

1. Add new lock file or change an existing one at:

    /etc/dconf/db/gdm.d/locks/
   

2. Append this line to it:

    /org/gnome/desktop/interface/text-scaling-factor
   

References:

• Shouldn't dconf-editor and gsettings access the same database?