Updating these VMs also allows you to receive various non-security bug fixes and enhancements both from the Qubes OS Project and from your upstream distro maintainer.
Advanced users can execute the standard update command for that operating system from the command line, e.g. `dnf update` in Fedora and `apt-get update` in Debian.
*`qubes-vm-*-current-testing` -- testing packages that will eventually land in the stable (`current`) repository
*`qubes-vm-*-security-testing` -- a subset of `qubes-vm-*-current-testing` that contains packages that qualify as security fixes
*`qubes-vm-*-unstable` -- packages that are not intended to land in the stable (`qubes-vm-*-current`) repository; mostly experimental debugging packages
Perhaps you've just updated your TemplateVM, and the update broke your template.
Or perhaps you've made a terrible mistake, like accidentally confirming the installation of an unsigned package that could be malicious.
If you want to undo changes to a TemplateVM, there are three basic methods:
1.**Root revert.**
This is appropriate for misconfigurations, but not for security concerns.
It will preserve your customizations.
2.**Reinstall the template.**
This is appropriate for both misconfigurations and security concerns, but you will lose all customizations.
3.**Full revert.**
This is appropriate for both misconfigurations and security concerns, and it can preserve your customizations.
However, it is a bit more complex.
### Root revert
**Important:** This command will roll back any changes made *during the last time the TemplateVM was run, but **not** before.*
This means that if you have already restarted the TemplateVM, using this command is unlikely to help, and you'll likely want to reinstall it from the repository instead.
On the other hand, if the template is already broken or compromised, it won't hurt to try reverting first.
Just make sure to **back up** all of your data and changes first!
1. Shut down `<template>`.
If you've already just shut it down, do **not** start it again (see above).
2. In a dom0 terminal:
qvm-volume revert <template>:root
### Reinstall the template
Please see [How to Reinstall a TemplateVM].
### Full revert
This is like the simple revert, except:
- You must also revert the private volume with `qvm-volume revert <template>:private`.
This requires you to have an old revision of the private volume, which does not exist with the current default config.
However, if you don't have anything important in the private volume (likely for a TemplateVM), then you can work around this by just resetting the private volume with `qvm-volume import --no-resize <template>:private /dev/null`.
- The saved revision of the volumes must be uncompromised.
With the default `revisions_to_keep=1` for the root volume, you must **not** have started the template since the compromising action.
When the installation requires internet connection to access third-party repositories, it will naturally fail when run in a Template VM because the default firewall rules for templates only allow connections from package managers.
So it is necessary to modify firewall rules to allow less restrictive internet access for the time of the installation, if one really wants to install those applications into a template.
As soon as software installation is completed, firewall rules should be returned back to the default state.
The user should decide by themselves whether such third-party applications should be equally trusted as the ones that come from the standard Fedora signed repositories and whether their installation will not compromise the default Template VM, and potentially consider installing them into a separate template or a standalone VM (in which case the problem of limited networking access doesn't apply by default), as described above.
Updates proxy is a service which allows access only from package managers.
This is meant to mitigate user errors (like using browser in the template VM), rather than some real isolation.
It is done with http proxy (tinyproxy) instead of simple firewall rules because it is hard to list all the repository mirrors (and keep that list up to date).
The proxy is used only to filter the traffic, not to cache anything.
The proxy is running in selected VMs (by default all the NetVMs (1)) and intercepts traffic directed to 10.137.255.254:8082.
Thanks to such configuration all the VMs can use the same proxy address, and if there is a proxy on network path, it will handle the traffic (of course when firewall rules allow that).
If the VM is configured to have access to the updates proxy (2), the startup scripts will automatically configure dnf to really use the proxy (3).
Also access to updates proxy is independent of any other firewall settings (VM will have access to updates proxy, even if policy is set to block all the traffic).
1.`qubes-updates-proxy` (and its deprecated name: `qubes-yum-proxy`) - a service providing a proxy for templates - by default enabled in NetVMs (especially: sys-net)
2.`updates-proxy-setup` (and its deprecated name: `yum-proxy-setup`) - use a proxy provided by another VM (instead of downloading updates directly), enabled by default in all templates
# any VM with tag `whonix-updatevm` should use `sys-whonix`; this tag is added to `whonix-gw` and `whonix-ws` during installation and is preserved during template clone
Snap packages do not use the normal update channels for Debian and Fedora (apt and dnf) and are often installed as the user rather than as root. To support these in an AppVM you need to take the following steps:
The refresh will take a few minutes; after it's complete the Snap app will appear in the AppVM's list of available applications. At this point the snap will be persistent within the AppVM and will receive updates when the AppVM is running.
If you want a desktop app to start automatically every time a qube starts you can create a link to it in the `~/.config/autostart` directory of the **AppVM**. This might be useful for Qubes that you set to automatically start on boot or for Qubes that have a set of apps you typically use all day, such as a chat app.
1. Open a terminal in the **AppVM** where you would like the app to launch.
2. List the names of the available desktop shortcuts by running the command `ls /usr/share/applications` and find the exact name of the shortcut to the app you want to autostart:
```shell_session
[user@example-AppVM ~]$ ls /usr/share/applications/
4. Make a link to the desktop app file you'd like to start in the autostart directory. For example, the command below will link the Thunderbird app into the autostart directory:
Note that the app will autostart only when the AppVM starts. If you would like the AppVM to autostart, select the "Start qube automatically on boot" checkbox in the AppVM's Qube Settings.
