aboutsummaryrefslogtreecommitdiff
path: root/systems/eldiron/borg_backup.nix
blob: f83594a7cd53fb635e2564280bf9bf03c814a478 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
{ lib, pkgs, config, name, ... }:

let
  cfg = config.myEnv.borg_backup;
  varDir = "/var/lib/borgbackup";
  borg_args = "--encryption repokey --make-parent-dirs init create prune compact check";
  borg_backup_full_with_ignored = pkgs.writeScriptBin "borg_full_with_ignored" ''
    #!${pkgs.stdenv.shell}

    if [ -z "$1" -o "$1" = "-h" -o "$1" = "--help" ]; then
      echo "borg_full_with_ignored /path/to/borgmatic.yaml"
      echo "Does a full backup including directories with .duplicity-ignore"
      exit 1
    fi
    ${pkgs.borgmatic}/bin/borgmatic -c "$1" --override 'storage.archive_name_format="{hostname}-with-ignored-{now:%Y-%m-%dT%H:%M:%S.%f}"' --override 'location.exclude_if_present=[]' ${borg_args}
  '';
  borg_backup = pkgs.writeScriptBin "borg_backup" ''
    #!${pkgs.stdenv.shell}

    declare -a profiles
    profiles=()
    ${builtins.concatStringsSep "\n" (lib.flatten (lib.mapAttrsToList (k: v: map (remote: [
      ''profiles+=("${remote}_${k}")''
    ]) v.remotes) config.services.borgBackup.profiles))}

    if [ -f "${varDir}/last_backup_profile" ]; then
      last_backup=$(cat ${varDir}/last_backup_profile)
      for i in "''${!profiles[@]}"; do
        if [[ "''${profiles[$i]}" = "$last_backup" ]]; then
          break
        fi
      done
      ((i+=1))
      profiles=("''${profiles[@]:$i}" "''${profiles[@]:0:$i}")
    fi

    # timeout in minutes
    timeout="''${1:-180}"
    timeout_timestamp=$(date +%s -d "$timeout minutes")
    for profile in "''${profiles[@]}"; do
      if [ $(date +%s -d "now") -ge "$timeout_timestamp" ]; then
        break
      fi

      touch "${varDir}/$profile.log"
      ${pkgs.borgmatic}/bin/borgmatic -c "${config.secrets.location}/borg_backup/$profile/borgmatic.yaml" ${borg_args} >> ${varDir}/$profile.log
      [[ $? = 0 ]] || echo -e "Error when doing backup for $profile, see above or logs in ${varDir}/$profile.log\n---------------------------------------" >&2
      echo "$profile" > ${varDir}/last_backup_profile
    done
  '';

  check_backups = pkgs.writeScriptBin "borg_list_not_backuped" ''
    #!${pkgs.stdenv.shell}

    do_check() {
      local dir="$1" path ignored_path
      find "$dir" -mindepth 1 -maxdepth 1 | while IFS= read -r path; do
        if ${pkgs.gnugrep}/bin/grep -qFx "$path" ${config.secrets.fullPaths."borg_backup/backuped_list"}; then
          continue
        elif ${pkgs.gnugrep}/bin/grep -q "^$path/" ${config.secrets.fullPaths."borg_backup/backuped_list"}; then
          do_check "$path"
        else
          while IFS= read -r ignored_path; do
            if [[ "$path" =~ ^$ignored_path$ ]]; then
              continue 2
            fi
          done < ${config.secrets.fullPaths."borg_backup/ignored_list"}
          printf '%s\n' "$path"
        fi
      done
    }

    do_check /var/lib
  '';
  borgProfile = profile: remote: bucket: builtins.toJSON {
    location = {
      source_directories = map (p: "${profile.rootDir}/${p}") profile.includedPaths;
      repositories = [
        { path = cfg.remotes.${remote}.remote name bucket; label = "backupserver"; }
      ];
      one_file_system = false;
      exclude_if_present = [".duplicity-ignore"];
      source_directories_must_exist = profile.directoriesMustExist;
      borgmatic_source_directory = "${varDir}/${profile.bucket}/.borgmatic";
    };
    storage = {
      encryption_passphrase = profile.password;
      ssh_command = "ssh -i ${config.secrets.fullPaths."borg_backup/identity"}";
      compression = "zlib";
      borg_base_directory = "${varDir}/${profile.bucket}";
      relocated_repo_access_is_ok = true;
    };
    retention = {
      keep_within = "10d";
      keep_daily = 30;
    };
  };
in
{
  options = {
    services.borgBackup.enable = lib.mkOption {
      type = lib.types.bool;
      default = false;
      description = ''
        Whether to enable remote backups.
      '';
    };
    services.borgBackup.profiles = lib.mkOption {
      type = lib.types.attrsOf (lib.types.submodule {
        options = {
          hash = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = ''
              Hash bucket and directory names
            '';
          };
          rootDir = lib.mkOption {
            type = lib.types.path;
            default = "/var/lib";
            description = ''
              Path to backup
              '';
          };
          password = lib.mkOption {
            type = lib.types.str;
            default = cfg.password;
            description = ''
              password to use to encrypt data
            '';
          };
          directoriesMustExist = lib.mkOption {
            type = lib.types.bool;
            default = true;
            description = ''
              Raise error if backuped directory doesn't exist
            '';
          };
          bucket = lib.mkOption {
            type = lib.types.str;
            description = ''
              Bucket to use
              '';
          };
          remotes = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            description = ''
              Remotes to use for backup
              '';
          };
          includedPaths = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            default = [];
            description = ''
              Included paths (subdirs of rootDir)
            '';
          };
          excludeFile = lib.mkOption {
            type = lib.types.lines;
            default = "";
            description = ''
              Content to put in exclude file
              '';
          };
          ignoredPaths = lib.mkOption {
            type = lib.types.listOf lib.types.str;
            default = [];
            description = ''
              List of paths to ignore when checking non-backed-up directories
              Can use (POSIX extended) regex
            '';
          };
        };
      });
    };
  };

  config = lib.mkIf config.services.borgBackup.enable {
    system.activationScripts.borg_backup = ''
      install -m 0700 -o root -g root -d ${varDir}
      '';
    secrets.keys = lib.listToAttrs (lib.flatten (lib.mapAttrsToList (k: v:
      let
        bucket = if v.hash or true then builtins.hashString "sha256" v.bucket else v.bucket;
      in map (remote: [
        (lib.nameValuePair "borg_backup/${remote}_${k}/borgmatic.yaml" {
          permissions = "0400";
          text = borgProfile v remote bucket;
        })
        (lib.nameValuePair "borg_backup/${remote}_${k}" {
          permissions = "0700";
          isDir = true;
        })
    ]) v.remotes) config.services.borgBackup.profiles)) // {
      "borg_backup/identity" = {
        permissions = "0400";
        text = "{{ .ssl_keys.borg_backup }}";
      };
      "borg_backup/ignored_list" = {
        permissions = "0400";
        text = let
            ignored = map
              (v: map (p: "${v.rootDir}/${p}") v.ignoredPaths)
              (builtins.attrValues config.services.borgBackup.profiles);
          in builtins.concatStringsSep "\n" (lib.flatten ignored);
      };
      "borg_backup/backuped_list" = {
        permissions = "0400";
        text = let
            included = map
              (v: map (p: "${v.rootDir}/${p}") v.includedPaths)
              (builtins.attrValues config.services.borgBackup.profiles);
          in builtins.concatStringsSep "\n" (lib.flatten included);
      };
    };

    programs.ssh.knownHostsFiles = [
      (pkgs.writeText
        "borg_backup_known_hosts"
        (builtins.concatStringsSep
          "\n"
          (builtins.filter
            (v: v != null)
            (builtins.map
              (v: v.sshKnownHosts)
              (builtins.attrValues cfg.remotes)
            )
          )
        )
      )
    ];
    environment.systemPackages = [ pkgs.borgbackup pkgs.borgmatic borg_backup_full_with_ignored borg_backup check_backups ];
    services.cron = {
      enable = true;
      systemCronJobs = [
        "0 0 * * * root ${borg_backup}/bin/borg_backup 300"
      ];

    };

  };
}