Ubuntu
------

Xenial (16.04)
~~~~~~~~~~~~~~

**How to override the default nameservers**


This files needs to be modified `/etc/dhcp/dhclient.conf`.
Use this directive :code:`supersede domain-name-servers 1.1.1.1, 1.0.0.1;`
Then restart the networking service :code:`# invoke-rc.d networking restart`

Note that most answers on askubuntu.com are complete bullshit.

Reference: https://askubuntu.com/questions/820667/how-do-i-permanently-configure-the-dns-server-list-in-16-04/887700#887700


Bionic (18.04)
~~~~~~~~~~~~~~

**How to override the default nameservers**

| Bionic uses netplan to handle the configuration of it's networking stack.
| Example of mininum valid netplan config:


.. code-block::

    root@devonh-desktop:/etc/netplan# cat /etc/netplan/01-network-manager-all.yaml 
    # Let NetworkManager manage all devices on this system
    network:
    version: 2
    renderer: networkd
    ethernets:
        enp3s0:
        dhcp4: yes
        dhcp6: no
        gateway4: 192.168.1.1 
        nameservers:
            addresses: [1.1.1.1, 1.0.0.1]


Note that ``renderer: NetworkManager`` will not work since this version of Ubuntu uses systemd-resolve as it's stub resolver.

Useful command to really see what nameservers you're using ``systemd-resolve --status``

**How to update default browser**

It needs to be set int he mimeapps.list. [#f1]_

.. code-block::
    
    All preferences about default applications your user located in file "mimeapps.list". I am use Gnome 3 and Debian, so for me it is ~/.config/mimeapps.list.

    I you don`t know where is may be located this file, try command:

    locate mimeapps.list
    For override default a web browser you need, at least, change values in category [Default Applications]

    x-scheme-handler/http
    text/html
    application/xhtml_xml
    image/webp
    x-scheme-handler/https
    x-scheme-handler/ftp
    x-scheme-handler/https
    x-scheme-handler/ftp
    and in category [Added Associations]

    text/html
    text/xml
    application/xhtml_xml
    image/webp
    x-scheme-handler/https
    x-scheme-handler/ftp
    For Opera the file ~/.config/mimeapps.list must contains:

    [Default Applications]
    x-scheme-handler/http=opera-browser.desktop
    text/html=opera-browser.desktop
    text/xml=opera-browser.desktop
    application/xhtml_xml=opera-browser.desktop
    image/webp=opera-browser.desktop
    x-scheme-handler/https=opera-browser.desktop
    x-scheme-handler/ftp=opera-browser.desktop

    [Added Associations]
    text/html=opera-browser.desktop;
    text/xml=opera-browser.desktop;
    application/xhtml_xml=opera-browser.desktop;
    image/webp=opera-browser.desktop;
    x-scheme-handler/https=opera-browser.desktop;
    x-scheme-handler/ftp=opera-browser.desktop;
    Try it (must be open in Opera, if it installed)

    xdg-open somehtmlfile.html
    For Chrome the file ~/.config/mimeapps.list must contains:

    [Default Applications]
    x-scheme-handler/http=google-chrome.desktop
    text/html=google-chrome.desktop
    text/xml=google-chrome.desktop
    application/xhtml_xml=google-chrome.desktop
    image/webp=google-chrome.desktop
    x-scheme-handler/https=google-chrome.desktop
    x-scheme-handler/ftp=google-chrome.desktop

    [Added Associations]
    text/html=google-chrome.desktop;
    text/xml=google-chrome.desktop;
    application/xhtml_xml=google-chrome.desktop;
    image/webp=google-chrome.desktop;
    x-scheme-handler/https=google-chrome.desktop;
    x-scheme-handler/ftp=google-chrome.desktop;

.. rubric:: References

.. [#f1] https://askubuntu.com/a/864698