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-rw-r--r--krebs/3modules/backup.nix138
1 files changed, 57 insertions, 81 deletions
diff --git a/krebs/3modules/backup.nix b/krebs/3modules/backup.nix
index d22dd3810..71b22d8cb 100644
--- a/krebs/3modules/backup.nix
+++ b/krebs/3modules/backup.nix
@@ -103,103 +103,91 @@ let
plan.method == method &&
config.krebs.build.host.name == plan.${side}.host.name;
- start = plan: pkgs.writeDash "backup.${plan.name}" ''
+ start = plan: let
+ login-name = "root";
+ identity = local.host.ssh.privkey.path;
+ ssh = "ssh -i ${shell.escape identity}";
+ local = getAttr plan.method {
+ push = plan.src // { rsync = src-rsync; };
+ pull = plan.dst // { rsync = dst-rsync; };
+ };
+ remote = getAttr plan.method {
+ push = plan.dst // { rsync = dst-rsync; };
+ pull = plan.src // { rsync = src-rsync; };
+ };
+ src-rsync = "rsync";
+ dst-rsync = concatStringsSep " && " [
+ "stat ${shell.escape plan.dst.path} >/dev/null"
+ "mkdir -m 0700 -p ${shell.escape plan.dst.path}/current"
+ "flock -n ${shell.escape plan.dst.path} rsync"
+ ];
+ in pkgs.writeScript "backup.${plan.name}" ''
+ #! ${pkgs.bash}/bin/bash
set -efu
+ start_date=$(date +%s)
+ ssh_target=${shell.escape login-name}@$(${fastest-address remote.host})
${getAttr plan.method {
push = ''
- identity=${shell.escape plan.src.host.ssh.privkey.path}
- src_path=${shell.escape plan.src.path}
- src=$src_path
- dst_user=root
- dst_host=$(${fastest-address plan.dst.host})
- dst_port=$(${network-ssh-port plan.dst.host "$dst_host"})
- dst_path=${shell.escape plan.dst.path}
- dst=$dst_user@$dst_host:$dst_path
- echo "update snapshot: current; $src -> $dst" >&2
- dst_shell() {
- exec ssh -F /dev/null \
- -i "$identity" \
- ''${dst_port:+-p $dst_port} \
- "$dst_user@$dst_host" \
- -T "$with_dst_path_lock_script"
- }
- rsh="ssh -F /dev/null -i $identity ''${dst_port:+-p $dst_port}"
- local_rsync() {
- rsync "$@"
- }
- remote_rsync=${shell.escape (concatStringsSep " && " [
- "mkdir -m 0700 -p ${shell.escape plan.dst.path}/current"
- "exec flock -n ${shell.escape plan.dst.path} rsync"
- ])}
+ rsync_src=${shell.escape plan.src.path}
+ rsync_dst=$ssh_target:${shell.escape plan.dst.path}
+ echo >&2 "update snapshot current; $rsync_src -> $rsync_dst"
'';
pull = ''
- identity=${shell.escape plan.dst.host.ssh.privkey.path}
- src_user=root
- src_host=$(${fastest-address plan.src.host})
- src_port=$(${network-ssh-port plan.src.host "$src_host"})
- src_path=${shell.escape plan.src.path}
- src=$src_user@$src_host:$src_path
- dst_path=${shell.escape plan.dst.path}
- dst=$dst_path
- echo "update snapshot: current; $dst <- $src" >&2
- dst_shell() {
- eval "$with_dst_path_lock_script"
- }
- rsh="ssh -F /dev/null -i $identity ''${src_port:+-p $src_port}"
- local_rsync() {
- mkdir -m 0700 -p ${shell.escape plan.dst.path}/current
- flock -n ${shell.escape plan.dst.path} rsync "$@"
- }
- remote_rsync=rsync
+ rsync_src=$ssh_target:${shell.escape plan.src.path}
+ rsync_dst=${shell.escape plan.dst.path}
+ echo >&2 "update snapshot current; $rsync_dst <- $rsync_src"
'';
}}
- # Note that this only works because we trust date +%s to produce output
- # that doesn't need quoting when used to generate a command string.
- # TODO relax this requirement by selectively allowing to inject variables
- # e.g.: ''${shell.quote "exec env NOW=''${shell.unquote "$NOW"} ..."}
- with_dst_path_lock_script="exec env start_date=$(date +%s) "${shell.escape
- "flock -n ${shell.escape plan.dst.path} /bin/sh"
- }
- local_rsync >&2 \
+ ${local.rsync} >&2 \
-aAXF --delete \
- --rsh="$rsh" \
- --rsync-path="$remote_rsync" \
- --link-dest="$dst_path/current" \
- "$src/" \
- "$dst/.partial"
- dst_shell < ${toFile "backup.${plan.name}.take-snapshots" ''
+ --rsh=${shell.escape ssh} \
+ --rsync-path=${shell.escape remote.rsync} \
+ --link-dest=${shell.escape plan.dst.path}/current \
+ "$rsync_src/" \
+ "$rsync_dst/.partial"
+
+ dst_exec() {
+ ${getAttr plan.method {
+ push = ''exec ${ssh} "$ssh_target" -T "exec$(printf ' %q' "$@")"'';
+ pull = ''exec "$@"'';
+ }}
+ }
+ dst_exec env \
+ start_date="$start_date" \
+ flock -n ${shell.escape plan.dst.path} \
+ /bin/sh < ${toFile "backup.${plan.name}.take-snapshots" ''
set -efu
: $start_date
- dst=${shell.escape plan.dst.path}
+ dst_path=${shell.escape plan.dst.path}
- mv "$dst/current" "$dst/.previous"
- mv "$dst/.partial" "$dst/current"
- rm -fR "$dst/.previous"
+ mv "$dst_path/current" "$dst_path/.previous"
+ mv "$dst_path/.partial" "$dst_path/current"
+ rm -fR "$dst_path/.previous"
echo >&2
snapshot() {(
: $ns $format $retain
name=$(date --date="@$start_date" +"$format")
- if ! test -e "$dst/$ns/$name"; then
+ if ! test -e "$dst_path/$ns/$name"; then
echo >&2 "create snapshot: $ns/$name"
- mkdir -m 0700 -p "$dst/$ns"
+ mkdir -m 0700 -p "$dst_path/$ns"
rsync >&2 \
-aAXF --delete \
- --link-dest="$dst/current" \
- "$dst/current/" \
- "$dst/$ns/.partial.$name"
- mv "$dst/$ns/.partial.$name" "$dst/$ns/$name"
+ --link-dest="$dst_path/current" \
+ "$dst_path/current/" \
+ "$dst_path/$ns/.partial.$name"
+ mv "$dst_path/$ns/.partial.$name" "$dst_path/$ns/$name"
echo >&2
fi
case $retain in
([0-9]*)
delete_from=$(($retain + 1))
- ls -r "$dst/$ns" \
+ ls -r "$dst_path/$ns" \
| sed -n "$delete_from,\$p" \
| while read old_name; do
echo >&2 "delete snapshot: $ns/$old_name"
- rm -fR "$dst/$ns/$old_name"
+ rm -fR "$dst_path/$ns/$old_name"
done
;;
(ALL)
@@ -227,24 +215,12 @@ let
| ${pkgs.coreutils}/bin/head -1; }
'';
- # Note that we don't escape word on purpose, so we can deref shell vars.
- # TODO type word
- network-ssh-port = host: word: ''
- case ${word} in
- ${concatStringsSep ";;\n" (mapAttrsToList
- (_: net: "(${head net.aliases}) echo ${toString net.ssh.port}")
- host.nets)};;
- esac
- '';
-
in out
# TODO ionice
-# TODO mail on failed push, pull
# TODO mail on missing push
# TODO don't cancel plans on activation
# also, don't hang while deploying at:
# starting the following units: backup.wu-home-xu.push.service, backup.wu-home-xu.push.timer
-# TODO make sure /bku is properly mounted
# TODO make sure that secure hosts cannot backup to insecure ones
# TODO optionally only backup when src and dst are near enough :)
# TODO try using btrfs for snapshots (configurable)