diff options
Diffstat (limited to 'tv/2configs/backup.nix')
| -rw-r--r-- | tv/2configs/backup.nix | 254 |
1 files changed, 254 insertions, 0 deletions
diff --git a/tv/2configs/backup.nix b/tv/2configs/backup.nix new file mode 100644 index 000000000..1cef0a6dc --- /dev/null +++ b/tv/2configs/backup.nix @@ -0,0 +1,254 @@ +{ config, lib, pkgs, ... }: +with lib; +let + # Users that are allowed to connect to the backup user. + # Note: the user must own a push plan destination otherwise no rsync. + backup-users = [ + config.krebs.users.tv + ]; + + ## TODO parse.file-location admit user + ## loc has the form <host-name>:<abs-path> + #parse.file-location = loc: let + # parts = splitString ":" loc; + # host-name = head parts; + # path = concatStringsSep ":" (tail parts); + #in { + # type = "types.krebs.file-location"; + # host = config.krebs.hosts.${host-name}; + # path = path; + #}; + + # TODO assert plan.dst.path & co + plans = with config.krebs.users; with config.krebs.hosts; addNames { + xu-test-cd = { + method = "push"; + #src = parse.file-location xu:/tmp/xu-test; + #dst = parse.file-location cd:/krebs/backup/xu-test; + src = { user = tv; host = xu; path = "/tmp/xu-test"; }; + dst = { user = tv; host = cd; path = "/krebs/backup/xu-test"; }; + startAt = "0,6,12,18:00"; + retain = { + hourly = 4; # sneakily depends on startAt + daily = 7; + weekly = 4; + monthly = 3; + }; + }; + #xu-test-wu = { + # method = "push"; + # dst = { user = tv; host = wu; path = "/krebs/backup/xu-test"; }; + #}; + cd-test-xu = { + method = "pull"; + #src = parse.file-location cd:/tmp/cd-test; + #dst = parse.file-location xu:/bku/cd-test; + src = { user = tv; host = cd; path = "/tmp/cd-test"; }; + dst = { user = tv; host = xu; path = "/bku/cd-test"; }; + }; + + }; + + out = { + #options.krebs.backup = api; + config = imp; + }; + + imp = { + users.groups.backup.gid = genid "backup"; + users.users = map makeUser (filter isPushDst (attrValues plans)); + systemd.services = + flip mapAttrs' (filterAttrs (_:isPushSrc) plans) (name: plan: { + name = "backup.${name}"; + value = makePushService plan; + }); + }; + + + # TODO getFQDN: admit hosts in other domains + getFQDN = host: "${host.name}.${config.krebs.search-domain}"; + + isPushSrc = plan: + plan.method == "push" && + plan.src.host.name == config.krebs.build.host.name; + + makePushService = plan: assert isPushSrc plan; { + startAt = plan.startAt; + serviceConfig.ExecStart = writeSh plan "rsync" '' + exec ${pkgs.rsync}/bin/rsync ${concatMapStringsSep " " shell.escape [ + "-a" + "-e" + "${pkgs.openssh}/bin/ssh -F /dev/null -i ${plan.src.host.ssh.privkey.path}" + "${plan.src.path}" + "${plan.name}@${getFQDN plan.dst.host}::push" + ]} + ''; + }; + + isPushDst = plan: + plan.method == "push" && + plan.dst.host.name == config.krebs.build.host.name; + + makeUser = plan: assert isPushDst plan; rec { + name = plan.name; + uid = genid name; + group = config.users.groups.backup.name; + home = plan.dst.path; + createHome = true; + shell = "${writeSh plan "shell" '' + case $2 in + 'rsync --server --daemon .') + exec ${backup.rsync plan [ "--server" "--daemon" "." ]} + ;; + ''') + echo "ERROR: no command specified" >&2 + exit 23 + ;; + *) + echo "ERROR: no unknown command: $SSH_ORIGINAL_COMMAND" >&2 + exit 23 + ;; + esac + ''}"; + openssh.authorizedKeys.keys = [ plan.src.host.ssh.pubkey ]; + }; + + rsync = plan: args: writeSh plan "rsync" '' + install -v -m 0700 -d ${plan.dst.path}/push >&2 + install -v -m 0700 -d ${plan.dst.path}/list >&2 + + ${pkgs.rsync}/bin/rsync \ + --config=${backup.rsyncd-conf plan { + post-xfer = writeSh plan "rsyncd.post-xfer" '' + case $RSYNC_EXIT_STATUS in 0) + exec ${backup.rsnapshot plan { + preexec = writeSh plan "rsnapshot.preexec" '' + touch ${plan.dst.path}/rsnapshot.$RSNAPSHOT_INTERVAL + ''; + postexec = writeSh plan "rsnapshot.postexec" '' + rm ${plan.dst.path}/rsnapshot.$RSNAPSHOT_INTERVAL + ''; + }} + esac + ''; + }} \ + ${toString (map shell.escape args)} + + fail=0 + for i in monthly weekly daily hourly; do + if test -e ${plan.dst.path}/rsnapshot.$i; then + rm ${plan.dst.path}/rsnapshot.$i + echo "ERROR: $i snapshot failed" >&2 + fail=1 + fi + done + if test $fail != 0; then + exit -1 + fi + ''; + + rsyncd-conf = plan: conf: pkgs.writeText "${plan.name}.rsyncd.conf" '' + fake super = yes + use chroot = no + lock file = ${plan.dst.path}/rsyncd.lock + + [push] + max connections = 1 + path = ${plan.dst.path}/push + write only = yes + read only = no + post-xfer exec = ${conf.post-xfer} + + [list] + path = ${plan.dst.path}/list + read only = yes + write only = no + ''; + + rsnapshot = plan: conf: writeSh plan "rsnapshot" '' + rsnapshot() { + ${pkgs.proot}/bin/proot \ + -b /bin \ + -b /nix \ + -b /run/current-system \ + -b ${plan.dst.path} \ + -r ${plan.dst.path} \ + -w / \ + ${pkgs.rsnapshot}/bin/rsnapshot \ + -c ${pkgs.writeText "${plan.name}.rsnapshot.conf" '' + config_version 1.2 + snapshot_root ${plan.dst.path}/list + cmd_cp ${pkgs.coreutils}/bin/cp + cmd_du ${pkgs.coreutils}/bin/du + #cmd_rm ${pkgs.coreutils}/bin/rm + cmd_rsync ${pkgs.rsync}/bin/rsync + cmd_rsnapshot_diff ${pkgs.rsnapshot}/bin/rsnapshot-diff + cmd_preexec ${conf.preexec} + cmd_postexec ${conf.postexec} + retain hourly 4 + retain daily 7 + retain weekly 4 + retain monthly 3 + lockfile ${plan.dst.path}/rsnapshot.pid + link_dest 1 + backup /push ./ + verbose 4 + ''} \ + "$@" + } + + cd ${plan.dst.path}/list/ + + now=$(date +%s) + is_older_than() { + test $(expr $now - $(date +%s -r $1 2>/dev/null || echo 0)) \ + -ge $2 + } + + # TODO report stale snapshots + # i.e. there are $interval.$i > $interval.$max + + hour_s=3600 + day_s=86400 + week_s=604800 + month_s=2419200 # 4 weeks + + set -- + + if test -e weekly.3 && is_older_than monthly.0 $month_s; then + set -- "$@" monthly + fi + + if test -e daily.6 && is_older_than weekly.0 $week_s; then + set -- "$@" weekly + fi + + if test -e hourly.3 && is_older_than daily.0 $day_s; then + set -- "$@" daily + fi + + if is_older_than hourly.0 $hour_s; then + set -- "$@" hourly + fi + + + if test $# = 0; then + echo "taking no snapshots" >&2 + else + echo "taking snapshots: $@" >&2 + fi + + export RSNAPSHOT_INTERVAL + for RSNAPSHOT_INTERVAL; do + rsnapshot "$RSNAPSHOT_INTERVAL" + done + ''; + + writeSh = plan: name: text: pkgs.writeScript "${plan.name}.${name}" '' + #! ${pkgs.dash}/bin/dash + set -efu + export PATH=${makeSearchPath "bin" (with pkgs; [ coreutils ])} + ${text} + ''; + +in out |