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-rw-r--r--tv/2configs/backup.nix254
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