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Prepare upgrade to nixos 20.03
[perso/Immae/Config/Nix.git] / modules / secrets.nix
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1a718805 1{ lib, pkgs, config, ... }:
44742a43 2{
1a718805 3 options.secrets = {
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4 keys = lib.mkOption {
5 type = lib.types.listOf lib.types.unspecified;
1a718805 6 default = [];
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7 description = "Keys to upload to server";
8 };
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9 location = lib.mkOption {
10 type = lib.types.path;
11 default = "/var/secrets";
12 description = "Location where to put the keys";
13 };
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14 # Read-only variables
15 fullPaths = lib.mkOption {
16 type = lib.types.attrsOf lib.types.path;
17 default = builtins.listToAttrs
18 (map (v: { name = v.dest; value = "${config.secrets.location}/${v.dest}"; }) config.secrets.keys);
19 readOnly = true;
20 description = "set of full paths to secrets";
21 };
44742a43 22 };
717ccfd9 23
44742a43 24 config = let
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25 location = config.secrets.location;
26 keys = config.secrets.keys;
44742a43 27 empty = pkgs.runCommand "empty" { preferLocalBuild = true; } "mkdir -p $out && touch $out/done";
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28 dumpKey = v: ''
29 mkdir -p secrets/$(dirname ${v.dest})
30 echo -n ${lib.strings.escapeShellArg v.text} > secrets/${v.dest}
31 cat >> mods <<EOF
32 ${v.user or "root"} ${v.group or "root"} ${v.permissions or "0600"} secrets/${v.dest}
33 EOF
34 '';
35 secrets = pkgs.runCommand "secrets.tar" {} ''
36 touch mods
37 tar --format=ustar --mtime='1970-01-01' -P --transform="s@${empty}@secrets@" -cf $out ${empty}/done
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38 ${builtins.concatStringsSep "\n" (map dumpKey keys)}
39 cat mods | while read u g p k; do
40 tar --format=ustar --mtime='1970-01-01' --owner="$u" --group="$g" --mode="$p" --append -f $out "$k"
41 done
42 '';
1a718805 43 in lib.mkIf (builtins.length keys > 0) {
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44 system.activationScripts.secrets = {
45 deps = [ "users" "wrappers" ];
46 text = ''
1a718805 47 install -m0750 -o root -g keys -d ${location}
44742a43 48 if [ -f /run/keys/secrets.tar ]; then
1a718805 49 if [ ! -f ${location}/currentSecrets ] || ! sha512sum -c --status "${location}/currentSecrets"; then
44742a43 50 echo "rebuilding secrets"
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51 TMP=$(${pkgs.coreutils}/bin/mktemp -d)
52 if [ -n "$TMP" ]; then
53 install -m0750 -o root -g keys -d $TMP
54 ${pkgs.gnutar}/bin/tar --strip-components 1 -C $TMP -xf /run/keys/secrets.tar
55 sha512sum /run/keys/secrets.tar > $TMP/currentSecrets
56 find $TMP -type d -exec chown root:keys {} \; -exec chmod o-rx {} \;
57 ${pkgs.rsync}/bin/rsync -O -c -av --delete $TMP/ ${location}
58 rm -rf $TMP
59 fi
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60 fi
61 fi
62 '';
63 };
64 deployment.keys."secrets.tar" = {
65 permissions = "0400";
66 # keyFile below is not evaluated at build time by nixops, so the
67 # `secrets` path doesn’t necessarily exist when uploading the
68 # keys, and nixops is unhappy.
69 user = "root${builtins.substring 10000 1 secrets}";
70 group = "root";
71 keyFile = "${secrets}";
72 };
73 };
74}