syncthing setup

bin/gen-syncthing-cert

@@ -0,0 +1,44 @@
+#!/bin/sh
+set -euo pipefail
+
+tmp=$(mktemp -d)
+trap 'rm -rf -- "$tmp"' EXIT
+
+FILEPATH="${MANAGED_CLIENTS:-./var/syncthing-managed-clients.json}"
+PKI_PATH="${PKI_PATH:-./pki/syncthing}"
+SECRETS_PATH="${SECRETS_PATH:-secrets/syncthing}"
+
+first_missing=$(
+    jq -r '
+        . as $root
+        | $root.managed_clients[]
+        | select($root.hashes[.] | not)
+    ' $FILEPATH \
+    | head -n 1 \
+)
+[ -z "$first_missing" ] && echo "Done" >&2 && exit 0
+
+echo "Generating cerificate for $first_missing"
+mkdir $tmp/$first_missing
+hash=$(
+    syncthing generate \
+        --config $tmp/$first_missing \
+        --data $tmp/$first_missing/data \
+        | grep -oP '(?<=device=)[A-Z0-9-]+' \
+)
+
+mkdir -p $PKI_PATH
+mv $tmp/$first_missing/cert.pem $PKI_PATH/$first_missing.cert
+
+# Remove the file so agenix does not try to decrypt
+[ -f "$SECRETS_PATH/$first_missing.age" ] && rm "$SECRETS_PATH/$first_missing.age"
+agenix -e $SECRETS_PATH/$first_missing.age < $tmp/$first_missing/key.pem
+
+jq --arg client "$first_missing" \
+    --arg hash "$hash" \
+    '.hashes[$client] = $hash' "$FILEPATH" \
+        > "$tmp/new-syncthing-managed-clients.json" \
+    && mv "$tmp/new-syncthing-managed-clients.json" "$FILEPATH"
+
+# Revoke self to handle next client
+"$0"

flake.nix

@@ -137,6 +137,8 @@
               colmena.packages.${system}.colmena
               agenix.packages.${system}.default
               pkgs.openssl
+              pkgs.jq
+              pkgs.syncthing
             ];
           };
         };

host/fw/default.nix

@@ -16,11 +16,12 @@
   ];
 
   imports = [
-    ./hardware-configuration.nix
     inputs.disko.nixosModules.disko
-    ./disko.nix
     inputs.nixos-hardware.nixosModules.framework-amd-ai-300-series
     inputs.lanzaboote.nixosModules.lanzaboote
+    ./disko.nix
+    ./hardware-configuration.nix
+    ./syncthing.nix
   ];
 
   # https://github.com/NixOS/nixos-hardware/issues/1603

host/fw/syncthing.nix

@@ -0,0 +1,8 @@
+{ ... }:
+{
+  services.syncthing = {
+    enable = true;
+    user = "hd";
+    configDir = "/home/hd/.config/syncthing";
+  };
+}

host/roam/syncthing.nix

@@ -1,6 +1,19 @@
 { ... }:
+let
+  guiAddress = "127.0.0.1:8384";
+in
 {
   services.syncthing = {
-    enable = false; # TODO
+    enable = true;
+    inherit guiAddress;
+  };
+
+  services.nginx = {
+    privateVirtualHosts."syncthing.roam.lan" = {
+      locations."/" = {
+        proxyPass = "http://${guiAddress}/";
+        proxyWebsockets = true;
+      };
+    };
   };
 }

mod/common/users.nix

@@ -23,7 +23,7 @@ with lib;
         extraGroups = [ "wheel" ];
         shell = pkgs.fish;
         packages = [ ];
-        openssh.authorizedKeys.keys = var.ssh-keys.trusted;
+        openssh.authorizedKeys.keys = var.ssh-keys.trusted-hd;
         hashedPasswordFile = config.age.secrets.hd-password.path;
       };
       users.root = {

mod/default.nix

@@ -5,5 +5,6 @@
     ./common
     ./desktop
     ./nginx.nix
+    ./syncthing.nix
   ];
 }

mod/syncthing.nix

@@ -0,0 +1,65 @@
+{
+  var,
+  config,
+  lib,
+  secrets,
+  ...
+}:
+let
+  cfg = config.services.syncthing;
+  this = config.networking.hostName;
+
+  is-managed = builtins.elem this var.syncthing-managed-clients.managed_clients;
+  is-server = this == "roam";
+  devices = lib.attrNames var.syncthing;
+  devices-without-this = lib.remove this devices;
+  type-encrypt = if is-server then "receiveencrypted" else "sendreceive";
+  devices-encrypt =
+    if is-server then
+      devices-without-this
+    else
+      lib.remove "roam" devices-without-this
+      ++ [
+        {
+          name = "roam";
+          encryptionPasswordFile = config.age.secrets.syncthing-password.path;
+        }
+      ];
+
+  folders = {
+    documents = {
+      id = "documents-hd";
+      path = if is-server then "/data/sync/documents-hd" else "/home/hd/Documents";
+      type = type-encrypt;
+      devices = devices-encrypt;
+      versioning = {
+        type = "simple";
+        params.keep = "10";
+      };
+    };
+  };
+in
+{
+  age.secrets.syncthing-password = lib.mkIf (cfg.enable && !is-server) {
+    file = secrets."syncthing-password.age";
+    mode = "440";
+    owner = config.services.syncthing.user;
+    group = config.services.syncthing.group;
+  };
+
+  age.secrets.syncthing-key = lib.mkIf (cfg.enable && is-managed) {
+    file = secrets.syncthing."${this}.age";
+    mode = "440";
+    owner = config.services.syncthing.user;
+    group = config.services.syncthing.group;
+  };
+
+  services.syncthing = lib.mkIf cfg.enable {
+    inherit folders;
+    settings = {
+      devices = var.syncthing;
+    };
+    key = lib.optionalAttrs is-managed config.age.secrets.syncthing-key.path;
+    cert = lib.optionalAttrs is-managed "${../pki/syncthing + "/${this}.cert"}";
+  };
+}

pki/syncthing/fw.cert

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

pki/syncthing/roam.cert

@@ -0,0 +1,11 @@
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----

secrets.nix

@@ -1,12 +1,29 @@
 let
   pkgs = import <nixpkgs> { };
   inherit (pkgs) lib;
-  keys = (import ./var { inherit lib; }).ssh-keys.root;
+  ssh-keys = (import ./var { inherit lib; }).ssh-keys;
+  keys = ssh-keys.root;
+  trusted-keys = ssh-keys.trusted-root;
   secrets = [
     "roam/rclone-conf"
     "roam/firefox-sync-secret"
     "hd-password"
     "tlskey"
   ];
+  trusted-secrets = [
+    # Can only be decrypted by clients
+    "syncthing-password"
+  ];
+  mkSecrets =
+    keys: secrets: lib.mergeAttrsList (map (x: { "secrets/${x}.age".publicKeys = keys; }) secrets);
+  syncthingManagedClients = (lib.importJSON ./var/syncthing-managed-clients.json).managed_clients;
+  mkSyncthingSecret = client: {
+    "secrets/syncthing/${client}.age".publicKeys = [ ssh-keys.by-host.root.${client} ];
+  };
+  syncthingSercrets = lib.mergeAttrsList (map mkSyncthingSecret syncthingManagedClients);
 in
-builtins.foldl' (acc: x: acc // { "secrets/${x}.age".publicKeys = keys; }) { } secrets
+lib.mergeAttrsList ([
+  (mkSecrets keys secrets)
+  (mkSecrets trusted-keys trusted-secrets)
+  (syncthingSercrets)
+])

secrets/syncthing-password.age

@@ -0,0 +1,10 @@
+age-encryption.org/v1
+-> ssh-ed25519 FTMbvw XgjPSuj97t3rQ4LUyKQUFrcFF6cwQMSJFjTJDAG/Nj0
+ygJ4dT50p4F92ZOEBOA9gZbQ6DoSFLF7ES1nNA+5EkI
+-> ssh-ed25519 ydxpSQ 32hIAyI93zJvZ9W/RwzLAMM+HuICDXiu6nkwZYryl0Y
+O2gITm4v/e40dVjE5KAeea+j4VwdYVnxXSTbKVmc1ag
+-> ssh-ed25519 IbE9zA Uvjx9kbxOt6zIVZsIiLValtgKeL7hufv8O45OrU7Nww
+yAzSC6ggAInYOfbh9DmcnoAbrun8LLTWpqF9YK9dzCw
+--- oVhNPf8TcFS/eZpcR0Yae3jddZziNWXPweId4HledhM
+„кÖ—¦
{
ät	•q[ö<>;qDª€ðr£LA}ªÚú‚ܬ~}œÙKD_zg
ýv(¡d¢
+âUÝì …<ð_òôåÄ
¹°¥Õ°§ðÞ<14>‘Õ¯Úå©žzœIúiä,²

secrets/syncthing/roam.age

@@ -0,0 +1,6 @@
+age-encryption.org/v1
+-> ssh-ed25519 gbs8eg hQNgGRxHRPhSq5iWURBpPd3nZDh4ofjOtGlC9V3jnWc
+AJ8CDyayy0kUoPiUp0LMyHRBeKjRZUTD9BbQYPKuw90
+--- nxoh+y+XGoihcSXsc9CW5/KzuDCQkbpjiiXMnfJVs3A
+á\vU¯:I~ù¯§t/u§ßדÍ<E2809C>YU<>w$7š8[”xƒ]
<0A>¸;nÜRëG9Ð<á	â ·úûþ×o,>áS–Ù¥Ë7Í¥aàB9láð{‚ˆ;;Úkä<6B>e7gjÃ<6A>¡$€¦
+e<EFBFBD>@8Èü³TÕÒñ;Ç€Ûã…ÌFužrLq¯váòËDîš8z"òªÐìãŽPT6nˆ<]<5D>

var/default.nix

@@ -1,13 +1,20 @@
-{ ... }@inputs:
+{
+  lib ? null,
+}:
 let
-  inputs' = inputs // {
+  lib' = if builtins.isNull lib then (import <nixpkgs> { }).lib else lib;
+  inputs' = {
+    lib = lib';
     var = outputs;
   };
+  load-var = x: import x inputs';
   # watch out for cycles
   outputs = {
-    "lan-dns" = import ./lan-dns.nix inputs';
-    "ssh-keys" = import ./ssh-keys.nix inputs';
-    "wg" = import ./wg.nix inputs';
+    "lan-dns" = load-var ./lan-dns.nix;
+    "ssh-keys" = load-var ./ssh-keys.nix;
+    "wg" = load-var ./wg.nix;
+    "syncthing" = load-var ./syncthing.nix;
+    "syncthing-managed-clients" = lib'.importJSON ./syncthing-managed-clients.json;
   };
 in
 outputs

var/lan-dns.nix

@@ -7,6 +7,7 @@ let
   }) var.wg.ips;
   custom-hosts = with var.wg.ips; {
     "git.lan" = roam;
+    "syncthing.roam.lan" = roam;
   };
 in
 rec {

var/ssh-keys.nix

@@ -16,12 +16,15 @@ let
     };
   };
   keys' = mkKeys keys;
+  mkTrusted =
+    user: with keys'.by-host.${user}; [
+      solo
+      c2
+      fw
+    ];
 in
 keys'
 // {
-  trusted = with keys'.by-host.hd; [
-    solo
-    c2
-    fw
-  ];
+  trusted-hd = mkTrusted "hd";
+  trusted-root = mkTrusted "root";
 }

var/syncthing-managed-clients.json

@@ -0,0 +1,10 @@
+{
+  "managed_clients": [
+    "fw",
+    "roam"
+  ],
+  "hashes": {
+    "fw": "YZGGXOT-MPFD7O4-ACLGOGT-LIMZVD3-7JBSZZR-LFCFWQL-BLO435I-LLH6GAL",
+    "roam": "HMB7ZRF-OODFHHW-2QCIFFJ-M7COVK5-YUB3GKT-SI56D2U-CPTTJEP-R3ZKOQ7"
+  }
+}

var/syncthing.nix

@@ -0,0 +1,18 @@
+{ var, lib, ... }:
+let
+  inherit (var.syncthing-managed-clients) managed_clients hashes;
+  unmanaged = {
+    # "roam".id = "OIKOKOT-LY4JWPX-T7OXE4D-I4ZC3IR-ZLMKFCO-IXSVEYZ-Y3FZOUB-LIG2XAO";
+  };
+in
+assert (
+  lib.assertMsg (
+    builtins.attrNames hashes == managed_clients
+  ) "Not all declaratively configured syncthing clients have keys. Rerun ./bin/gen-syncthing-cert"
+);
+assert (
+  lib.assertMsg (
+    [ ] == (lib.intersectLists managed_clients (builtins.attrNames unmanaged))
+  ) "Syncthing clients must either be unmanaged or declaratively configured."
+);
+unmanaged // builtins.mapAttrs (_: v: { id = v; }) hashes