--- /dev/null
+# inspired from https://nixos.wiki/wiki/Virtualization_in_NixOS
+{ config, pkgs, lib, pkgs-no-overlay, ... }@args:
+let
+ toImage = f: "${import ./vms/base_image.nix f (args // { myEnv = config.myEnv; })}/nixos.qcow2";
+in
+{
+ options = {
+ myServices.vms.libvirt-guests = lib.mkOption {
+ type = lib.types.attrsOf (lib.types.submodule {
+ options = {
+ network = lib.mkOption { type = lib.types.str; description = "network to attach the guest to"; };
+ pool = lib.mkOption { type = lib.types.str; description = "pool to attach the guest to"; };
+ cpus = lib.mkOption { type = lib.types.int; default = 1; description = "number of cpus to assign"; };
+ memory = lib.mkOption { type = lib.types.int; description = "memory in GiB to assign"; };
+ diskSize = lib.mkOption { type = lib.types.int; description = "disk size in GiB"; };
+ destroyVolumeOnExit = lib.mkOption { type = lib.types.bool; description = "Whether to destroy the volume on exit"; default = false; };
+ extraDevicesXML = lib.mkOption { type = lib.types.lines; description = "Extra device configuration"; default = ""; };
+ preStart = lib.mkOption { type = lib.types.lines; default = ""; description = "Script to run as prestart"; };
+ };
+ });
+ default = {};
+ description = "Libvirt guests to start";
+ };
+ myServices.vms.libvirt-networks = lib.mkOption {
+ type = lib.types.attrsOf (lib.types.submodule {
+ options = {
+ bridgeNumber = lib.mkOption { type = lib.types.int; description = "bridge interface to create virbr<nbr>"; };
+ ipRange = lib.mkOption { type = lib.types.str; example = "192.168.100"; description = "ip4 prefix to use"; };
+ };
+ });
+ description = "Libvirt networks to configure";
+ default = {};
+ };
+ myServices.vms.libvirt-pools = lib.mkOption {
+ type = lib.types.attrsOf (lib.types.submodule {
+ options = {
+ type = lib.mkOption { type = lib.types.enum [ "dir" "zfs" ]; description = "Pool type"; };
+ target = lib.mkOption { type = lib.types.nullOr lib.types.path; default = null; description = "where to find images"; };
+ preStart = lib.mkOption { type = lib.types.lines; default = ""; description = "Script to run as prestart"; };
+ xml = lib.mkOption { type = lib.types.lines; default = ""; description = "Additional configuration"; };
+ };
+ });
+ };
+ myServices.vms.libvirt-images = lib.mkOption {
+ type = lib.types.attrsOf lib.types.path;
+ default = {};
+ description = "Attrs of images to create in /etc/libvirtd/base-images";
+ };
+ };
+ config = lib.mkMerge [
+ # Define images
+ {
+ environment.etc = lib.mapAttrs'
+ (n: v: lib.nameValuePair "libvirtd/base-images/${n}.qcow2" { source = toImage v; })
+ config.myServices.vms.libvirt-images;
+ }
+
+ # Define networks
+ {
+ systemd.services = lib.mapAttrs' (name: network: lib.nameValuePair "libvirtd-network-${name}" {
+ after = [ "libvirtd.service" ];
+ requires = [ "libvirtd.service" ];
+ wantedBy = [ "multi-user.target" ];
+ serviceConfig = {
+ Type = "oneshot";
+ RemainAfterExit = "yes";
+ };
+ path = [ config.boot.zfs.package ];
+ script = let
+ xml = pkgs.writeText "libvirt-network-${name}.xml" ''
+ <network>
+ <name>${name}</name>
+ <uuid>UUID</uuid>
+ <forward mode='nat' />
+ <bridge name='virbr${builtins.toString network.bridgeNumber}' />
+ <domain name='${name}' localOnly='yes'/>
+ <ip address='${network.ipRange}.1' netmask='255.255.255.0'>
+ <dhcp>
+ <range start='${network.ipRange}.2' end='${network.ipRange}.254'/>
+ </dhcp>
+ </ip>
+ </network>
+ '';
+ in ''
+ uuid="$(${pkgs.libvirt}/bin/virsh net-uuid '${name}' || true)"
+ ${pkgs.libvirt}/bin/virsh net-define <(sed "s/UUID/$uuid/" '${xml}')
+ ${pkgs.libvirt}/bin/virsh net-start '${name}'
+ '';
+ preStop = ''
+ ${pkgs.libvirt}/bin/virsh net-destroy '${name}'
+ '';
+ }) config.myServices.vms.libvirt-networks;
+ }
+
+ # Define pools
+ {
+ systemd.services = lib.mapAttrs' (name: pool: lib.nameValuePair "libvirtd-pool-${name}" {
+ after = [ "libvirtd.service" ];
+ requires = [ "libvirtd.service" ];
+ wantedBy = [ "multi-user.target" ];
+ serviceConfig = {
+ Type = "oneshot";
+ RemainAfterExit = "yes";
+ };
+ path = [ config.boot.zfs.package ];
+ script = let
+ xml = pkgs.writeText "libvirt-pool-${name}.xml" ''
+ <pool type="${pool.type}">
+ <name>${name}</name>
+ <uuid>UUID</uuid>
+ ${pool.xml}
+ ${if pool.target != null then ''
+ <target>
+ <path>${pool.target}</path>
+ </target>
+ '' else ""}
+ </pool>
+ '';
+ in pool.preStart + ''
+ uuid="$(${pkgs.libvirt}/bin/virsh pool-uuid '${name}' || true)"
+ ${pkgs.libvirt}/bin/virsh pool-define <(sed "s/UUID/$uuid/" '${xml}')
+ ${pkgs.libvirt}/bin/virsh pool-start '${name}' || true
+ '';
+ }) config.myServices.vms.libvirt-pools;
+ }
+
+ # Define guests
+ {
+ systemd.services = lib.mapAttrs' (name: guest: lib.nameValuePair "libvirtd-guest-${name}" {
+ after = [ "libvirtd.service" "libvirtd-pool-${guest.pool}.service" "libvirtd-network-${guest.network}.service" ];
+ requires = [ "libvirtd.service" "libvirtd-pool-${guest.pool}.service" "libvirtd-network-${guest.network}.service" ];
+ wantedBy = [ "multi-user.target" ];
+ serviceConfig = {
+ Type = "oneshot";
+ RemainAfterExit = "yes";
+ };
+ path = [ config.boot.zfs.package ];
+ script =
+ let
+ xml = pkgs.writeText "libvirt-guest-${name}.xml"
+ ''
+ <domain type="kvm">
+ <name>${name}</name>
+ <uuid>UUID</uuid>
+ <memory unit="GiB">${builtins.toString guest.memory}</memory>
+ <vcpu>${builtins.toString guest.cpus}</vcpu>
+ <os>
+ <type arch="x86_64">hvm</type>
+ </os>
+ <devices>
+ <emulator>/run/current-system/sw/bin/qemu-system-x86_64</emulator>
+ <disk type="volume">
+ <source pool="${guest.pool}" volume="guest-${name}" />
+ <target dev="vda" bus="virtio"/>
+ </disk>
+ ${guest.extraDevicesXML}
+ <input type="keyboard" bus="usb"/>
+ <graphics type="vnc" port="-1" autoport="yes"/>
+ <interface type="network">
+ <source network="${guest.network}" />
+ </interface>
+ </devices>
+ <features>
+ <acpi/>
+ </features>
+ </domain>
+ '';
+ in
+ guest.preStart + ''
+ if ! ${pkgs.libvirt}/bin/virsh vol-key 'guest-${name}' --pool ${guest.pool} &> /dev/null; then
+ ${pkgs.libvirt}/bin/virsh vol-create-as --pool ${guest.pool} --name 'guest-${name}' --capacity '${builtins.toString guest.diskSize}GiB'
+ volume_path=$(${pkgs.libvirt}/bin/virsh vol-path --pool ${guest.pool} --vol 'guest-${name}')
+ ${pkgs-no-overlay.qemu}/bin/qemu-img convert /etc/libvirtd/base-images/nixos.qcow2 $volume_path
+ fi
+ uuid="$(${pkgs.libvirt}/bin/virsh domuuid '${name}' || true)"
+ ${pkgs.libvirt}/bin/virsh define <(sed "s/UUID/$uuid/" '${xml}')
+ ${pkgs.libvirt}/bin/virsh start '${name}'
+ '';
+ preStop = ''
+ ${pkgs.libvirt}/bin/virsh shutdown '${name}'
+ let "timeout = $(date +%s) + 10"
+ while [ "$(${pkgs.libvirt}/bin/virsh list --name | grep --count '^${name}$')" -gt 0 ]; do
+ if [ "$(date +%s)" -ge "$timeout" ]; then
+ # Meh, we warned it...
+ ${pkgs.libvirt}/bin/virsh destroy '${name}'
+ else
+ # The machine is still running, let's give it some time to shut down
+ sleep 0.5
+ fi
+ done
+ '' + lib.optionalString guest.destroyVolumeOnExit ''
+ if ${pkgs.libvirt}/bin/virsh vol-key 'guest-${name}' --pool ${guest.pool} &> /dev/null; then
+ ${pkgs.libvirt}/bin/virsh vol-wipe --pool ${guest.pool} --vol 'guest-${name}' || true
+ ${pkgs.libvirt}/bin/virsh vol-delete --pool ${guest.pool} --vol 'guest-${name}'
+ fi
+ '';
+ }) config.myServices.vms.libvirt-guests;
+ }
+ ];
+}
projects / perso / Immae / Config / Nix.git / blobdiff