pyrox.dev
services.libvirtd.autoSnapshot: init
+2
-1
ci/OWNERS
+2
-1
ci/OWNERS
+2
nixos/doc/manual/release-notes/rl-2511.section.md
+2
nixos/doc/manual/release-notes/rl-2511.section.md
···
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developers to build scalable applications without sacrificing productivity or
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reliability. Available as [services.temporal](#opt-services.temporal.enable).
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## Backward Incompatibilities {#sec-release-25.11-incompatibilities}
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<!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
···
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developers to build scalable applications without sacrificing productivity or
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reliability. Available as [services.temporal](#opt-services.temporal.enable).
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- `services.libvirtd.autoSnapshot`, a backup service for libvirt managed vms.
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## Backward Incompatibilities {#sec-release-25.11-incompatibilities}
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<!-- To avoid merge conflicts, consider adding your item at an arbitrary place in the list instead. -->
+1
nixos/modules/module-list.nix
+1
nixos/modules/module-list.nix
+260
nixos/modules/services/backup/libvirtd-autosnapshot.nix
+260
nixos/modules/services/backup/libvirtd-autosnapshot.nix
···
···
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{
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config,
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lib,
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pkgs,
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...
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}:
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let
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cfg = config.services.libvirtd.autoSnapshot;
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+
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# Function to get VM config with defaults
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getVMConfig =
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vm:
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if lib.isString vm then
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{
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name = vm;
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inherit (cfg) snapshotType keep;
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}
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else
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{
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inherit (vm) name;
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snapshotType = if vm.snapshotType != null then vm.snapshotType else cfg.snapshotType;
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keep = if vm.keep != null then vm.keep else cfg.keep;
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};
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# Main backup script combining all VM scripts
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backupScript = ''
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set -eo pipefail
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+
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# Initialize failure tracking
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failed=""
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+
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# Define the VM snapshot function
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function snap_vm() {
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local vmName="$1"
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local snapshotType="$2"
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local keep="$3"
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+
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# Add validation for VM name
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if ! echo "$vmName" | ${pkgs.gnugrep}/bin/grep -qE '^[a-zA-Z0-9_.-]+$'; then
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echo "Invalid VM name: '$vmName'"
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failed="$failed $vmName"
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return
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fi
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echo "Processing VM: $vmName"
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# Check if VM exists
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if ! ${pkgs.libvirt}/bin/virsh dominfo "$vmName" >/dev/null 2>&1; then
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echo "VM '$vmName' does not exist, skipping"
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return
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fi
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+
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# Create new snapshot
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local snapshot_name
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snapshot_name="${cfg.prefix}_$(date +%Y-%m-%d_%H%M%S)"
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local snapshot_opts=""
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[[ "$snapshotType" == "external" ]] && snapshot_opts="--disk-only"
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if ! ${pkgs.libvirt}/bin/virsh snapshot-create-as \
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"$vmName" \
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"$snapshot_name" \
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"Automatic backup snapshot" \
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$snapshot_opts \
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--atomic; then
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echo "Failed to create snapshot for $vmName"
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failed="$failed $vmName"
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return
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fi
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# List all automatic snapshots for this VM
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readarray -t SNAPSHOTS < <(${pkgs.libvirt}/bin/virsh snapshot-list "$vmName" --name | ${pkgs.gnugrep}/bin/grep "^${cfg.prefix}_")
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# Count snapshots
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local snapshot_count=''${#SNAPSHOTS[@]}
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# Delete old snapshots if we have more than the keep limit
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if [[ $snapshot_count -gt $keep ]]; then
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# Sort snapshots by date (they're named with date prefix)
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readarray -t TO_DELETE < <(printf '%s\n' "''${SNAPSHOTS[@]}" | ${pkgs.coreutils}/bin/sort | ${pkgs.coreutils}/bin/head -n -$keep)
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for snap in "''${TO_DELETE[@]}"; do
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echo "Removing old snapshot $snap from $vmName"
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# Check if snapshot is internal or external
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local snapshot_location
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snapshot_location=$(${pkgs.libvirt}/bin/virsh snapshot-info "$vmName" --snapshotname "$snap" | ${pkgs.gnugrep}/bin/grep "Location:" | ${pkgs.gawk}/bin/awk '{print $2}')
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local delete_opts=""
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[[ "$snapshot_location" == "internal" ]] && delete_opts="--metadata"
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if ! ${pkgs.libvirt}/bin/virsh snapshot-delete "$vmName" "$snap" $delete_opts; then
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echo "Failed to remove snapshot $snap from $vmName"
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failed="$failed $vmName(cleanup)"
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fi
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done
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fi
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}
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${
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if cfg.vms == null then
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''
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# Process all VMs
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${pkgs.libvirt}/bin/virsh list --all --name | while read -r vm; do
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# Skip empty lines
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[ -z "$vm" ] && continue
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# Call snap_vm function with default settings
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snap_vm "$vm" ${cfg.snapshotType} ${toString cfg.keep}
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done
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''
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else
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''
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# Process specific VMs from the list
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${lib.concatMapStrings (
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vm: with getVMConfig vm; "snap_vm '${name}' ${snapshotType} ${toString keep}\n"
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) cfg.vms}
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''
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}
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# Report any failures
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if [ -n "$failed" ]; then
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echo "Snapshot operation failed for:$failed"
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exit 1
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fi
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exit 0
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'';
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in
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{
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options = {
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services.libvirtd.autoSnapshot = {
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enable = lib.mkEnableOption "LibVirt VM snapshots";
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+
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calendar = lib.mkOption {
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type = lib.types.str;
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default = "04:15:00";
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description = ''
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When to create snapshots (systemd calendar format).
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Default is 4:15 AM.
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'';
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};
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+
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prefix = lib.mkOption {
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type = lib.types.str;
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default = "autosnap";
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description = ''
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Prefix for automatic snapshot names.
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This is used to identify and manage automatic snapshots
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separately from manual ones.
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'';
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};
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+
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keep = lib.mkOption {
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type = lib.types.int;
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default = 2;
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description = "Default number of snapshots to keep for VMs that don't specify a keep value.";
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};
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+
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snapshotType = lib.mkOption {
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type = lib.types.enum [
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"internal"
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"external"
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];
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default = "internal";
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description = "Type of snapshot to create (internal or external).";
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};
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+
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vms = lib.mkOption {
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type = lib.types.nullOr (
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lib.types.listOf (
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lib.types.oneOf [
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lib.types.str
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(lib.types.submodule {
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options = {
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name = lib.mkOption {
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type = lib.types.str;
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description = "Name of the VM";
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};
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snapshotType = lib.mkOption {
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type = lib.types.nullOr (
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lib.types.enum [
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"internal"
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"external"
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]
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);
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default = null;
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description = ''
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Type of snapshot to create (internal or external).
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If not specified, uses global snapshotType (${toString cfg.snapshotType}).
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'';
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};
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keep = lib.mkOption {
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type = lib.types.nullOr lib.types.int;
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default = null;
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description = ''
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Number of snapshots to keep for this VM.
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If not specified, uses global keep (${toString cfg.keep}).
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'';
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};
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};
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})
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]
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)
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);
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default = null;
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description = ''
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If specified only the list of VMs will be snapshotted else all existing one. Each entry can be either:
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- A string (VM name, uses default settings)
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- An attribute set with VM configuration
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'';
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example = lib.literalExpression ''
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[
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"myvm1" # Uses defaults
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{
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name = "myvm2";
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keep = 30; # Override retention
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}
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]
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'';
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};
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};
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};
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+
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config = lib.mkIf cfg.enable {
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assertions = [
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{
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assertion = (cfg.vms == null) || (lib.isList cfg.vms && cfg.vms != [ ]);
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message = "'services.libvirtd.autoSnapshot.vms' must either be null for all VMs or a non-empty list of VM configurations";
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}
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{
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assertion = config.virtualisation.libvirtd.enable;
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message = "virtualisation.libvirtd must be enabled to use services.libvirtd.autoSnapshot";
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}
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];
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+
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systemd = {
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timers.libvirtd-autosnapshot = {
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description = "LibVirt VM snapshot timer";
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wantedBy = [ "timers.target" ];
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timerConfig = {
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OnCalendar = cfg.calendar;
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AccuracySec = "5m";
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Unit = "libvirtd-autosnapshot.service";
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};
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};
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services.libvirtd-autosnapshot = {
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description = "LibVirt VM snapshot service";
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after = [ "libvirtd.service" ];
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requires = [ "libvirtd.service" ];
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serviceConfig = {
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Type = "oneshot";
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User = "root";
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};
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script = backupScript;
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};
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};
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};
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+
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meta.maintainers = [ lib.maintainers._6543 ];
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}