hosts/oignon/backup.nix

   1 { pkgs, lib, config, hostName, ... }:
   2 with builtins;
   3 {
   4 # syncoid --create-bookmark --no-privilege-elevation --no-sync-snap --recvoptions '' --sendoptions raw --recursive oignon/home off2/julm/backup/oignon/home
   5 # zfs list -t snapshot -o name | grep ^oignon/home | while read -r snap; do zfs bookmark "$snap" "${snap//@/#}"; done
   6 # Take regular snapshots, and prune old ones
   7 services.sanoid = {
   8   enable = true;
   9   extraArgs = [ "--verbose" ];
  10   datasets = {
  11     "${hostName}/home" = {
  12       autosnap = true;
  13       autoprune = true;
  14       hourly = 12;
  15       daily = 3;
  16       monthly = 0;
  17       yearly = 0;
  18       recursive = true;
  19     };
  20     "${hostName}/var" = {
  21       autosnap = true;
  22       autoprune = true;
  23       hourly = 12;
  24       daily = 1;
  25       monthly = 0;
  26       yearly = 0;
  27       recursive = true;
  28     };
  29     "off2/julm/backup/oignon" = {
  30       autosnap = false;
  31       autoprune = true;
  32       hourly = 0;
  33       daily = 7;
  34       monthly = 3;
  35       yearly = 0;
  36       recursive = true;
  37     };
  38   };
  39 };
  40 # Trigger backups when disks are plugged
  41 services.udev.extraRules = ''
  42   ACTION=="add",    SUBSYSTEM=="block", KERNEL=="sd*", ENV{ID_SERIAL}=="WDC_WD10JPVT-22A1YT0_WD-WX21AC2F3987", ENV{SYSTEMD_WANTS}+="zfs-local-backup-home@WD10JPVT.service", ENV{SYSTEMD_ALIAS}="/sys/subsystem/usb/WD10JPVT"
  43   # See https://github.com/systemd/systemd/issues/7587#issuecomment-381428545
  44   ACTION=="remove", SUBSYSTEM=="block", KERNEL=="sd*", ENV{ID_SERIAL}=="WDC_WD10JPVT-22A1YT0_WD-WX21AC2F3987", TAG+="systemd"
  45 '';
  46 # Show what's happening to the user
  47 systemd.services."zfs-term@" = {
  48   description = "ZFS terminal for: %I";
  49   unitConfig.StopWhenUnneeded = false;
  50   environment.DISPLAY = ":0";
  51   environment.XAUTHORITY = "/home/julm/.Xauthority";
  52   after = [ "graphical.target" ];
  53   bindsTo = [ "sys-subsystem-usb-%i.device" ];
  54   serviceConfig = {
  55     Type = "simple";
  56     PrivateTmp = true;
  57     ExecStart = pkgs.writeShellScript "zfs-force-import" ''
  58       DESTPOOL=$1
  59       set -eux
  60       ${pkgs.xterm}/bin/xterm -fg white -bg black -fa Monospace -fs 6 \
  61         -title "ZFS backup to: $DESTPOOL" -e "journalctl -f -o short \
  62         -u zfs-force-import@$DESTPOOL \
  63         -u zfs-local-backup-home@$DESTPOOL"
  64     '' + " %I";
  65   };
  66 };
  67 # Force zpool import, even if the disk has not been exported, or has been imported on another computer
  68 systemd.services."zfs-force-import@" = {
  69   description = "ZFS force import: %I";
  70   unitConfig = {
  71     StartLimitBurst = 5;
  72     StartLimitInterval = 200;
  73     StopWhenUnneeded = true;
  74   };
  75   wants = [ "zfs-term@%i.service" ];
  76   bindsTo = [ "sys-subsystem-usb-%i.device" ];
  77   path = lib.mkBefore [ "/run/booted-system/sw" ];
  78   serviceConfig = {
  79     Type = "oneshot";
  80     RemainAfterExit = true;
  81     PrivateTmp = true;
  82     SyslogIdentifier = "zfs-force-import@%i";
  83     Restart = "on-failure";
  84     ExecStart = pkgs.writeShellScript "zfs-force-import" ''
  85       DESTPOOL=$1
  86       set -eux
  87       # Import the zpool, using stable paths
  88       zpool import -d /dev/disk/by-id/ || true
  89       zpool import -lFd /dev/disk/by-id/ "$DESTPOOL" ||
  90       zpool reopen "$DESTPOOL" ||
  91       zpool import -f -d /dev/disk/by-id/ "$DESTPOOL" ||
  92       zpool clear -nFX "$DESTPOOL"
  93     '' + " %I";
  94   };
  95 };
  96 # Prune old snapshots on the backup and send new ones
  97 systemd.services."zfs-local-backup-home@" = {
  98   description = "ZFS backup home, on: %I";
  99   wants = [ "zfs-term@%i.service" ];
 100   after = [ "zfs-force-import@%i.service" ];
 101   requires = [ "zfs-force-import@%i.service" ];
 102   bindsTo = [ "sys-subsystem-usb-%i.device" ];
 103   path = lib.mkBefore [ "/run/booted-system/sw" ];
 104   serviceConfig = rec {
 105     Type = "oneshot";
 106     PrivateTmp = true;
 107     CacheDirectory = [ "zfs-usb-backup/%I" ];
 108     RuntimeDirectory = [ "zfs-usb-backup/%I" ];
 109     User = "julm";
 110     Group = "users";
 111     SyslogIdentifier = "zfs-local-backup-home@%i";
 112     ExecStartPre = "+" + pkgs.writeShellScript "zfs-local-backup-home-startPre" ''
 113       DESTPOOL=$1
 114       set -eux
 115       if zpool status "$DESTPOOL"; then
 116         zfs allow ${User} bookmark,hold,mount,send ${hostName}/home
 117         zfs allow ${User} bookmark,create,destroy,load-key,mount,mountpoint,receive,rollback,snapshot "$DESTPOOL"/${User}
 118         zpool scrub -p "$DESTPOOL" || true
 119       fi
 120     '' + " %I";
 121     ExecStart = pkgs.writeShellScript "zfs-local-backup-home" ''
 122       set -eu
 123       DESTPOOL=$1
 124       # sanoid is quite conservative:
 125       # by setting hourly=24, a snapshot must be >24 hours old
 126       # and there must been >24 total hourly snapshots,
 127       # or nothing is pruned.
 128       install -D -m 400 /dev/stdin /tmp/sanoid/sanoid.conf <<EOF
 129         [template_remote]
 130         autoprune=true
 131         autosnap=false
 132         process_children_only=false
 133
 134         [$DESTPOOL/${User}/backup/${hostName}/home]
 135         hourly=6
 136         daily=31
 137         monthly=3
 138         recursive=true
 139         use_template=remote
 140       EOF
 141       set -x
 142       ${pkgs.sanoid}/bin/sanoid \
 143         --cache-dir /var/cache/zfs-usb-backup/"$DESTPOOL" \
 144         --configdir /tmp/sanoid \
 145         --prune-snapshots \
 146         --run-dir /run/zfs-usb-backup/"$DESTPOOL" \
 147         --verbose
 148
 149       for dataset in ${hostName}/home; do
 150         ${pkgs.sanoid}/bin/syncoid \
 151           --create-bookmark \
 152           --exclude "home/room" \
 153           --force-delete \
 154           --no-privilege-elevation \
 155           --no-sync-snap \
 156           --recursive \
 157           --recvoptions "" \
 158           --sendoptions raw  \
 159           --skip-parent \
 160           "$dataset" \
 161           "$DESTPOOL"/${User}/backup/"$dataset"
 162       done
 163     '' + " %I";
 164     ExecStartPost = "+" + pkgs.writeShellScript "zfs-local-backup-home-startPost" ''
 165       DESTPOOL=$1
 166       set -eux
 167       # Only if the zpool still exists to avoid uninterruptible hanging
 168       if zpool status -v "$DESTPOOL"; then
 169         # Scrub the zpool 1 minute (in the background)
 170         zpool scrub "$DESTPOOL"
 171         sleep 60
 172       fi
 173       while zpool status -v "$DESTPOOL"; do
 174         zpool scrub -p "$DESTPOOL" || true
 175         sleep 20
 176         # Export the zpool (to avoid a forced import later on)
 177         zpool export "$DESTPOOL" || true
 178       done
 179       systemctl --no-block stop zfs-term@"$DESTPOOL"
 180     '' + " %I";
 181   };
 182 };
 183 programs.bash.interactiveShellInit = ''
 184   mount-zfs-backup () {
 185     (
 186     set -eux
 187     zpool="$1"
 188     zpool status "$zpool" 2>/dev/null ||
 189     sudo zpool import -d /dev/disk/by-id/ "$zpool"
 190     trap "sudo zpool export $zpool" EXIT
 191     zfs list -rH -t filesystem -o mounted,mountpoint,name "$zpool"/"$USER"/backup |
 192     grep "^no\\s*/" | cut -f 3 | xargs -ortL1 sudo zfs mount -Olv || true
 193     ${pkgs.mate.caja-with-extensions}/bin/caja --browser /mnt/"$zpool"/"$USER"/backup
 194     )
 195   }
 196 '';
 197 programs.bash.shellAliases = {
 198   mount-backup-WD10JPVT = "mount-zfs-backup WD10JPVT";
 199 };
 200 }