qusal/salt/sys-cacher

sys-cacher

Caching proxy server for software repositories in Qubes OS.

Table of Contents

• Description
• Installation
• Usage
  • Report Page and Maintenance Tasks
  • Connect to the cacher via IP instead of Qrexec
  • Non-TemplateVMs integration
• Uninstallation
• Credits

Description

The caching proxy is "sys-cacher" based on apt-cacher-ng, it stores downloaded packages, so that you need only download a package once for it to be used when updating many The proxy is preconfigured to work out of the box for Debian, Ubuntu, Arch, and Fedora

When you install this package, qubes will be tagged with "updatevm-sys-cacher" and they will be altered to use the proxy by default. When there is "https://" in your repository definitions, the entries will be changed in the templates from to "http://HTTPS///". This is so that the request to the proxy is plain text, and the proxy will then make the request via https.

This change will be done automatically for every template that exists and is not Whonix based. No changes are made to Whonix templates, and updates to those templates will not be cached.

Installation

Installation may take a long time as it will target all templates unless you specify otherwise.

• Top

qubesctl top.enable sys-cacher browser
qubesctl --targets=tpl-browser,sys-cacher-browser,tpl-sys-cacher,sys-cacher state.apply
qubesctl top.disable sys-cacher browser
qubesctl state.apply sys-cacher.appmenus,sys-cacher.tag
qubesctl --skip-dom0 --templates state.apply sys-cacher.install-client

• State

qubesctl state.apply sys-cacher.create
qubesctl --skip-dom0 --targets=tpl-browser state.apply browser.install
qubesctl --skip-dom0 --targets=tpl-sys-cacher state.apply sys-cacher.install
qubesctl --skip-dom0 --targets=sys-cacher state.apply sys-cacher.configure
qubesctl --skip-dom0 --targets=sys-cacher-browser state.apply sys-cacher.configure-browser
qubesctl state.apply sys-cacher.appmenus,sys-cacher.tag
qubesctl --skip-dom0 --templates state.apply sys-cacher.install-client

Usage

Report Page and Maintenance Tasks

The report page is available from sys-cacher and sys-cacher-browser at http://127.0.0.1:8082/acng-report.html and any other client qube that has sys-cacher as it's update qube. This is apt-cacher-ng limitation and is bad security wise, every client has administrative access to the cacher qube. You should add the following to the end of sys-cacher rc.local:

echo "AdminAuth: username:password" | tee /etc/qubes-apt-cacher-ng/zzz_security.conf

Where username and password are HTTP Auth strings.

If you want to view statistics or manage the server through a GUI, open sys-cacher or sys-cacher-browser desktop file cacher-browser.desktop from Dom0. Addresses starting with http or https will be redirected to sys-cacher-browser.

The browser separation from the server is to avoid browsing malicious sites and exposing the browser to direct network on the same machine the server is running. The browser qube is offline and only has access to the admin interface. In other words, it has control over the server functions, if the browser is compromised, it can compromise the server.

Connect to the cacher via IP instead of Qrexec

Because the sys-cacher qube is listening on port 8082, you can use it from non-template qubes and qubes that do not have a working Qrexec. Use the native configuration to set the update proxy using the IP address of sys-cacher by setting the cacher as the netvm of the client qube.

Non-TemplateVMs integration

Attention: this method will allow for a client qube to bypass the qubes firewall and connect to a remote via the updates proxy.

By default, only templates will use the proxy to update, if you want to cache Non-TemplateVMs updates or simply make them functional again, the qube will need the service.updates-proxy-setup feature set:

qubesctl --skip-dom0 --targets=QUBE state.apply sys-cacher.install-client
qvm-tags add QUBE updatevm-sys-cacher
qvm-features QUBE service.updates-proxy-setup 1

Don't forget to restart the qube.

If you don't want or can't restart the qube, such as DispVMs, where you would lose you session, run the same commands as above plus the following inside the qube:

sudo touch /var/run/qubes-service/updates-proxy-setup
sudo /usr/lib/qubes/update-proxy-configs
sudo systemctl restart qubes-updates-proxy-forwarder.socket

Uninstallation

• Top:

qubesctl top.enable sys-cacher.deinit
qubesctl --templates state.apply
qubesctl top.disable sys-cacher.deinit

• State:

qubesctl state.apply sys-cacher.remove-policy
qubesctl state.apply sys-cacher.untag
qubesctl --skip-dom0 --templates state.apply sys-cacher.uninstall-client

If you want to use the standard proxy for a few templates:

qubesctl --skip-dom0 --targets=TEMPLATE state.apply sys-cacher.uninstall-client
qvm-tags del TEMPLATE updatevm-sys-cacher

Credits

• Unman