NixOS Wiki

Libvirt: Difference between revisions

← Older edit
VisualWikitext
imported>Onny
mNo edit summary
Added a note for why you won't find hooks files after switching.
 
(22 intermediate revisions by 10 users not shown)
Line 6: Line 6:


{{file|/etc/nixos/configuration.nix|nix|<nowiki>
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
virtualisation.libvirtd = {
virtualisation.libvirtd.enable = true;
  enable = true;
 
  qemu = {
# Enable TPM emulation (optional)
    package = pkgs.qemu_kvm;
virtualisation.libvirtd.qemu = {
    runAsRoot = true;
  swtpm.enable = true;
    swtpm.enable = true;
  ovmf.packages = [ pkgs.OVMFFull.fd ];
    ovmf = {
      enable = true;
      packages = [(pkgs.unstable.OVMF.override {
        secureBoot = true;
        tpmSupport = true;
      }).fd];
    };
  };
};
};
# Enable USB redirection (optional)
virtualisation.spiceUSBRedirection.enable = true;
</nowiki>}}
</nowiki>}}


Line 34: Line 30:


=== UEFI with OVMF ===
=== UEFI with OVMF ===
Enable UEFI firmware support, following Qemu configuration for your local user is required
{{file|~/.config/libvirt/qemu.conf|nix|<nowiki>
# Adapted from /var/lib/libvirt/qemu.conf
# Note that AAVMF and OVMF are for Aarch64 and x86 respectively
nvram = [ "/run/libvirt/nix-ovmf/AAVMF_CODE.fd:/run/libvirt/nix-ovmf/AAVMF_VARS.fd", "/run/libvirt/nix-ovmf/OVMF_CODE.fd:/run/libvirt/nix-ovmf/OVMF_VARS.fd" ]
</nowiki>}}


See [https://ostechnix.com/enable-uefi-support-for-kvm-virtual-machines-in-linux/ this tutorial] on how to run a guest machine in UEFI mode using <code>virt-manager</code>.
See [https://ostechnix.com/enable-uefi-support-for-kvm-virtual-machines-in-linux/ this tutorial] on how to run a guest machine in UEFI mode using <code>virt-manager</code>.
Line 99: Line 87:


{{file|/etc/nixos/configuration.nix|nix|<nowiki>
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
networking.interfaces.enp1s0.ipv4.addresses = [{
networking.interfaces.enp1s0 = {
  address = "10.25.0.2";
  ipv4.addresses = [{
  prefixLength = 24;
    address = "10.25.0.2";
}];
    prefixLength = 24;
  }];
  defaultGateway = {
    address = "10.25.0.1";
    interface = "ens1s0";
  };
};
</nowiki>}}
</nowiki>}}


The host should now be able to reach the guest via the bridge interface and vice versa.
The host should now be able to reach the guest via the bridge interface and vice versa.
=== File sharing ===
In order to share files between host and guest, one recommended way of doing this is to use <code>spice-webdavd</code>.
Shutdown the client, in this example named <code>my_guest</code>, and edit the libvirt XML file.
<syntaxhighlight lang="bash">
virsh edit my_guest
</syntaxhighlight>
Add the following snippet after <code><channel type='unix'>[...]</channel></code> part inside the devices subsection:
<syntaxhighlight lang="bash">
    <channel type='spiceport'>
      <source channel='org.spice-space.webdav.0'/>
      <target type='virtio' name='org.spice-space.webdav.0'/>
      <address type='virtio-serial' controller='0' bus='0' port='3'/>
    </channel>
</syntaxhighlight>
Start the guest machine. Inside the guest, add following part to your system configuration and apply it
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
services.spice-webdavd.enable = true;
</nowiki>}}
List available shares for the guest
<syntaxhighlight lang="bash">
curl localhost:9843
</syntaxhighlight>
Mount an example share called <code>myshare</code> to the mountpoint <code>myshare</code>
{{file|/etc/nixos/configuration.nix|nix|<nowiki>
services.davfs2 = {
  enable = true;
  settings.globalSection.ask_auth = 0;
};
fileSystems = {
  "/root/myshare" = {
    device = "http://localhost:9843/myshare";
    fsType = "davfs";
    options = [ "nofail" ];
  };
};
</nowiki>}}
=== Hooks ===
Libvirt allows the use of hooks to run custom scripts during specific events, such as daemon lifecycle events, domain lifecycle events, and network events. On NixOS, you can configure hooks via the NixOS module to automate the placement of hook scripts in the appropriate directories.
The following directories are used for placing hook scripts:
* '''<code>/var/lib/libvirt/hooks/daemon.d/</code>'''  Scripts here are triggered by daemon events like start, shutdown, and SIGHUP.
* '''<code>/var/lib/libvirt/hooks/qemu.d/</code>'''  Scripts for handling QEMU domain events such as begin, end, and migration.
* '''<code>/var/lib/libvirt/hooks/lxc.d/</code>'''  Scripts for LXC container events like begin and end.
* '''<code>/var/lib/libvirt/hooks/libxl.d/</code>'''  Scripts for Xen domains managed by <code>libxl</code> (begin/end events).
* '''<code>/var/lib/libvirt/hooks/network.d/</code>'''  Scripts triggered by network events such as begin and end.
See the [https://libvirt.org/hooks.html libvirt documentation] for more information.
An example config would be:<syntaxhighlight lang="nix">
{
  virtualisation.libvirtd.hooks = {
    daemon = {
      "example" = ./scripts/daemon-example.sh;
    };
    qemu = {
      "example" = ./scripts/qemu-example.sh;
    };
    network = {
      "example" = ./scripts/network-example.sh;
    };
  };
}
</syntaxhighlight>Note that after you added the configuration and switch, you'll have the following command to setup the hooks.<syntaxhighlight lang="bash">
systemctl start libvirtd-config.service
</syntaxhighlight>


== Clients ==
== Clients ==
Line 116: Line 190:


Following are notes regarding the use of some of those tools
Following are notes regarding the use of some of those tools
==== error: cannot find any suitable libguestfs supermin ====
Use use the package libguestfs-with-appliance. See https://github.com/NixOS/nixpkgs/issues/37540
=== guestfs-tools ===
Includes virt-sysprep, used to prepare a VM image for use.  Review the manpage of virt-sysprep, virt-clone, and virt-builder.


==== <code>virt-builder</code> ====
==== <code>virt-builder</code> ====


virt-builder is installed with <code>libguestfs</code>, but has some issues from its packaging.
virt-builder is installed with <code>guestfs-tools</code>, but has some issues from its packaging.


It is possible to work around those issues without modifying the package (when a pristine nixpkgs is needed).
It is possible to work around those issues without modifying the package (when a pristine nixpkgs is needed).
Line 132: Line 216:


This will make your user use the shipped repo configurations, and works around the fact that virt-builder reads its executable name to build its configuration path. The executable being wrapped, it is named differently.
This will make your user use the shipped repo configurations, and works around the fact that virt-builder reads its executable name to build its configuration path. The executable being wrapped, it is named differently.
[[Category:Virtualization]]
==== error: cannot find any suitable libguestfs supermin ====
Use use the package libguestfs-with-appliance. See https://github.com/NixOS/nixpkgs/issues/37540


=== guestfs-tools ===
=== NixVirt ===


Includes virt-sysprep, used to prepare a VM image for use.  Review the manpage of virt-sysprep, virt-clone, and virt-builder.
[https://github.com/AshleyYakeley/NixVirt NixVirt] is a flake that provides NixOS and Home Manager modules for setting up libvirt domains, networks and pools declaratively.


=== Accessing QEMU VMs through Webbrowser ===
=== Accessing QEMU VMs through Webbrowser ===
Line 183: Line 262:
==== Get EyeOS Spice Web Client ====
==== Get EyeOS Spice Web Client ====


As said, the experience with the EyeOS Spice Web Client has been the best so far. Another client would be the [https://cgit.freedesktop.org/spice/spice-html5/ spice-html5] from freedesktop.org.
As said, the experience with the EyeOS Spice Web Client has been the best so far. Another client would be the [https://gitlab.freedesktop.org/spice/spice-html5/ spice-html5] from freedesktop.org.


1. Download the [https://github.com/eyeos/spice-web-client/ EyeOS Spice Web Client] and unpack it (if necessary) or , as example, just <code>git clone https://github.com/eyeos/spice-web-client/ /var/www/spice</code>
1. Download the [https://github.com/eyeos/spice-web-client/ EyeOS Spice Web Client] and unpack it (if necessary) or , as example, just <code>git clone https://github.com/eyeos/spice-web-client/ /var/www/spice</code>
Line 226: Line 305:


And finally you can access the VMs GUI through <code>https://mydomain.tld:4500/spice/index.html?host=mydomain.tld&port=5959</code>
And finally you can access the VMs GUI through <code>https://mydomain.tld:4500/spice/index.html?host=mydomain.tld&port=5959</code>
[[Category:Virtualization]]
[[Category:Applications]]
Retrieved from "https://wiki.nixos.org/wiki/Libvirt"