Merge remote-tracking branch 'cd/master'

krebs/3modules/backup.nix

@@ -0,0 +1,286 @@
+{ config, lib, pkgs, ... }:
+with lib;
+let
+  out = {
+    options.krebs.backup = api;
+    config = mkIf cfg.enable imp;
+  };
+
+  cfg = config.krebs.backup;
+
+  api = {
+    enable = mkEnableOption "krebs.backup" // { default = true; };
+    plans = mkOption {
+      default = {};
+      type = types.attrsOf (types.submodule ({
+        # TODO enable = mkEnableOption "TODO" // { default = true; };
+        options = {
+          method = mkOption {
+            type = types.enum ["pull" "push"];
+          };
+          name = mkOption {
+            type = types.str;
+          };
+          src = mkOption {
+            type = types.krebs.file-location;
+          };
+          dst = mkOption {
+            type = types.krebs.file-location;
+          };
+          startAt = mkOption {
+            type = types.str;
+          };
+          snapshots = mkOption {
+            type = types.attrsOf (types.submodule {
+              options = {
+                format = mkOption {
+                  type = types.str; # TODO date's +FORMAT
+                };
+                retain = mkOption {
+                  type = types.nullOr types.int;
+                  default = null; # null = retain all snapshots
+                };
+              };
+            });
+          };
+        };
+      }));
+    };
+  };
+
+  imp = {
+    users.groups.backup.gid = genid "backup";
+    users.users = {}
+      // {
+        root.openssh.authorizedKeys.keys =
+          map (plan: plan.dst.host.ssh.pubkey)
+              (filter isPullSrc (attrValues cfg.plans))
+          ++
+          map (plan: plan.src.host.ssh.pubkey)
+              (filter isPushDst (attrValues cfg.plans))
+          ;
+      }
+      ;
+    systemd.services =
+      flip mapAttrs' (filterAttrs (_:isPullDst) cfg.plans) (name: plan: {
+        name = "backup.${name}.pull";
+        value = makePullService plan;
+      })
+      //
+      flip mapAttrs' (filterAttrs (_:isPushSrc) cfg.plans) (name: plan: {
+        name = "backup.${name}.push";
+        value = makePushService plan;
+      })
+      ;
+  };
+
+  isPushSrc = plan:
+    plan.method == "push" &&
+    plan.src.host.name == config.krebs.build.host.name;
+
+  isPullSrc = plan:
+    plan.method == "pull" &&
+    plan.src.host.name == config.krebs.build.host.name;
+
+  isPushDst = plan:
+    plan.method == "push" &&
+    plan.dst.host.name == config.krebs.build.host.name;
+
+  isPullDst = plan:
+    plan.method == "pull" &&
+    plan.dst.host.name == config.krebs.build.host.name;
+
+  # TODO push destination needs this in the dst.user's PATH
+  service-path = [
+    pkgs.coreutils
+    pkgs.gnused
+    pkgs.openssh
+    pkgs.rsync
+    pkgs.utillinux
+  ];
+
+  # TODO if there is plan.user, then use its privkey
+  makePushService = plan: assert isPushSrc plan; {
+    path = service-path;
+    serviceConfig = {
+      ExecStart = push plan;
+      Type = "oneshot";
+    };
+    startAt = plan.startAt;
+  };
+
+  makePullService = plan: assert isPullDst plan; {
+    path = service-path;
+    serviceConfig = {
+      ExecStart = pull plan;
+      Type = "oneshot";
+    };
+    startAt = plan.startAt;
+  };
+
+  push = plan: let
+    # We use writeDashBin and return the absolute path so systemd will produce
+    # nice names in the log, i.e. without the Nix store hash.
+    out = "${main}/bin/${main.name}";
+
+    main = writeDashBin "backup.${plan.name}.push" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      mkdir -m 0700 -p "$dst"
+      exec flock -n "$dst" ${critical-section}
+    '';
+
+    critical-section = writeDash "backup.${plan.name}.push.critical-section" ''
+      # TODO check if there is a previous
+      set -efu
+      identity=${shell.escape plan.src.host.ssh.privkey.path}
+      src=${shell.escape plan.src.path}
+      dst_target=${shell.escape "root@${getFQDN plan.dst.host}"}
+      dst_path=${shell.escape plan.dst.path}
+      dst=$dst_target:$dst_path
+
+      # Export NOW so runtime of rsync doesn't influence snapshot naming.
+      export NOW
+      NOW=$(date +%s)
+
+      echo >&2 "update snapshot: current; $src -> $dst"
+      rsync >&2 \
+          -aAXF --delete \
+          -e "ssh -F /dev/null -i $identity" \
+          --rsync-path ${shell.escape
+            "mkdir -m 0700 -p ${shell.escape plan.dst.path} && rsync"} \
+          --link-dest="$dst_path/current" \
+          "$src/" \
+          "$dst/.partial"
+
+      exec ssh -F /dev/null \
+          -i "$identity" \
+          "$dst_target" \
+          -T \
+          env NOW="$NOW" /bin/sh < ${remote-snapshot}
+      EOF
+    '';
+
+    remote-snapshot = writeDash "backup.${plan.name}.push.remote-snapshot" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      if test -e "$dst/current"; then
+        mv "$dst/current" "$dst/.previous"
+      fi
+      mv "$dst/.partial" "$dst/current"
+      rm -fR "$dst/.previous"
+      echo >&2
+
+      (${(take-snapshots plan).text})
+    '';
+
+  in out;
+
+  # TODO admit plan.dst.user and its ssh identity
+  pull = plan: let
+    # We use writeDashBin and return the absolute path so systemd will produce
+    # nice names in the log, i.e. without the Nix store hash.
+    out = "${main}/bin/${main.name}";
+
+    main = writeDashBin "backup.${plan.name}.pull" ''
+      set -efu
+      dst=${shell.escape plan.dst.path}
+
+      mkdir -m 0700 -p "$dst"
+      exec flock -n "$dst" ${critical-section}
+    '';
+
+    critical-section = writeDash "backup.${plan.name}.pull.critical-section" ''
+      # TODO check if there is a previous
+      set -efu
+      identity=${shell.escape plan.dst.host.ssh.privkey.path}
+      src=${shell.escape "root@${getFQDN plan.src.host}:${plan.src.path}"}
+      dst=${shell.escape plan.dst.path}
+
+      # Export NOW so runtime of rsync doesn't influence snapshot naming.
+      export NOW
+      NOW=$(date +%s)
+
+      echo >&2 "update snapshot: current; $dst <- $src"
+      mkdir -m 0700 -p ${shell.escape plan.dst.path}
+      rsync >&2 \
+          -aAXF --delete \
+          -e "ssh -F /dev/null -i $identity" \
+          --link-dest="$dst/current" \
+          "$src/" \
+          "$dst/.partial"
+      mv "$dst/current" "$dst/.previous"
+      mv "$dst/.partial" "$dst/current"
+      rm -fR "$dst/.previous"
+      echo >&2
+
+      exec ${take-snapshots plan}
+    '';
+  in out;
+
+  take-snapshots = plan: writeDash "backup.${plan.name}.take-snapshots" ''
+    set -efu
+    NOW=''${NOW-$(date +%s)}
+    dst=${shell.escape plan.dst.path}
+
+    snapshot() {(
+      : $ns $format $retain
+      name=$(date --date="@$NOW" +"$format")
+      if ! test -e "$dst/$ns/$name"; then
+        echo >&2 "create snapshot: $ns/$name"
+        mkdir -m 0700 -p "$dst/$ns"
+        rsync >&2 \
+            -aAXF --delete \
+            --link-dest="$dst/current" \
+            "$dst/current/" \
+            "$dst/$ns/.partial.$name"
+        mv "$dst/$ns/.partial.$name" "$dst/$ns/$name"
+        echo >&2
+      fi
+      case $retain in
+        ([0-9]*)
+          delete_from=$(($retain + 1))
+          ls -r "$dst/$ns" \
+            | sed -n "$delete_from,\$p" \
+            | while read old_name; do
+                echo >&2 "delete snapshot: $ns/$old_name"
+                rm -fR "$dst/$ns/$old_name"
+              done
+          ;;
+        (ALL)
+          :
+          ;;
+      esac
+    )}
+
+    ${concatStringsSep "\n" (mapAttrsToList (ns: { format, retain ? null, ... }:
+      toString (map shell.escape [
+        "ns=${ns}"
+        "format=${format}"
+        "retain=${if retain == null then "ALL" else toString retain}"
+        "snapshot"
+      ]))
+      plan.snapshots)}
+  '';
+
+  # TODO getFQDN: admit hosts in other domains
+  getFQDN = host: "${host.name}.${config.krebs.search-domain}";
+
+  writeDash = name: text: pkgs.writeScript name ''
+    #! ${pkgs.dash}/bin/dash
+    ${text}
+  '';
+
+  writeDashBin = name: text: pkgs.writeTextFile {
+    executable = true;
+    destination = "/bin/${name}";
+    name = name;
+    text = ''
+      #! ${pkgs.dash}/bin/dash
+      ${text}
+    '';
+  };
+
+in out

krebs/3modules/default.nix

@@ -7,6 +7,7 @@ let
   out = {
     imports = [
       ./apt-cacher-ng.nix
+      ./backup.nix
       ./bepasty-server.nix
       ./build.nix
       ./buildbot/master.nix

krebs/4lib/types.nix

@@ -177,4 +177,21 @@ types // rec {
   addr6 = str;
   hostname = str;
   label = str;
+
+  krebs.file-location = types.submodule {
+    options = {
+      # TODO user
+      host = mkOption {
+        type = host;
+      };
+      # TODO merge with ssl.privkey.path
+      path = mkOption {
+        type = types.either types.path types.str;
+        apply = x: {
+          path = toString x;
+          string = x;
+        }.${typeOf x};
+      };
+    };
+  };
 }

tv/2configs/backup.nix

@@ -0,0 +1,42 @@
+{ config, lib, ... }:
+with lib;
+{
+  krebs.backup.plans = addNames {
+    xu-test-cd = {
+      method = "push";
+
+      src = { host = config.krebs.hosts.xu; path = "/tmp/xu-test"; };
+      dst = { host = config.krebs.hosts.cd; path = "/tmp/backups/xu-test"; };
+
+      #startAt = "0,6,12,18:00";
+      startAt = "minutely";
+      snapshots = {
+        minutely = { format = "%Y-%m-%dT%H:%M"; retain =  5; };
+        hourly   = { format = "%Y-%m-%dT%H";    retain =  4; };
+        daily    = { format = "%Y-%m-%d";       retain =  7; };
+        weekly   = { format = "%YW%W";          retain =  4; };
+        monthly  = { format = "%Y-%m";          retain = 12; };
+        yearly   = { format = "%Y";                          };
+      };
+    };
+    #xu-test-wu = {
+    #  method = "push";
+    #  dst = { user = tv; host = wu; path = "/krebs/backup/xu-test"; };
+    #};
+    cd-test-xu = {
+      method = "pull";
+      src = { host = config.krebs.hosts.cd; path = "/tmp/cd-test"; };
+      dst = { host = config.krebs.hosts.xu; path = "/tmp/backups/cd-test"; };
+      startAt = "minutely";
+      snapshots = {
+        minutely = { format = "%Y-%m-%dT%H:%M"; retain =  5; };
+        hourly   = { format = "%Y-%m-%dT%H";    retain =  4; };
+        daily    = { format = "%Y-%m-%d";       retain =  7; };
+        weekly   = { format = "%YW%W";          retain =  4; };
+        monthly  = { format = "%Y-%m";          retain = 12; };
+        yearly   = { format = "%Y";                          };
+      };
+    };
+
+  };
+}

tv/2configs/default.nix

@@ -28,6 +28,7 @@ with lib;
 
   imports = [
     <secrets>
+    ./backup.nix
     ./vim.nix
     {
       # stockholm dependencies

tv/2configs/vim.nix

@@ -4,7 +4,7 @@ with lib;
 let
   out = {
     environment.systemPackages = [
-      pkgs.vim
+      vim
     ];
 
     # Nano really is just a stupid name for Vim.
@@ -22,14 +22,38 @@ let
     "${pkgs.vimPlugins.undotree}/share/vim-plugins/undotree"
   ];
 
+  dirs = {
+    backupdir = "$HOME/.cache/vim/backup";
+    swapdir   = "$HOME/.cache/vim/swap";
+    undodir   = "$HOME/.cache/vim/undo";
+  };
+  files = {
+    viminfo   = "$HOME/.cache/vim/info";
+  };
+
+  mkdirs = let
+    dirOf = s: let out = concatStringsSep "/" (init (splitString "/" s));
+               in assert out != ""; out;
+    alldirs = attrValues dirs ++ map dirOf (attrValues files);
+  in unique (sort lessThan alldirs);
+
+  vim = pkgs.writeScriptBin "vim" ''
+    #! ${pkgs.dash}/bin/dash
+    set -f
+    umask 0077
+    ${concatStringsSep "\n" (map (x: "mkdir -p ${x}") mkdirs)}
+    umask 0022
+    exec ${pkgs.vim}/bin/vim "$@"
+  '';
+
   vimrc = pkgs.writeText "vimrc" ''
     set nocompatible
 
     set autoindent
     set backspace=indent,eol,start
     set backup
-    set backupdir=$HOME/.vim/backup/
-    set directory=$HOME/.vim/cache//
+    set backupdir=${dirs.backupdir}/
+    set directory=${dirs.swapdir}//
     set hlsearch
     set incsearch
     set mouse=a
@@ -40,11 +64,11 @@ let
     set showcmd
     set showmatch
     set ttimeoutlen=0
-    set undodir=$HOME/.vim/undo
+    set undodir=${dirs.undodir}
     set undofile
     set undolevels=1000000
     set undoreload=1000000
-    set viminfo='20,<1000,s100,h,n$HOME/.vim/cache/info
+    set viminfo='20,<1000,s100,h,n${files.viminfo}
     set visualbell
     set wildignore+=*.o,*.class,*.hi,*.dyn_hi,*.dyn_o
     set wildmenu

tv/2configs/xserver/default.nix

@@ -48,7 +48,7 @@ let
       "slock"
     ];
 
-    systemd.services.display-manager = mkForce {};
+    systemd.services.display-manager.enable = false;
 
     services.xserver.enable = true;