use wgautomesh service definition from my nixpkgs PR

deploy_nixos

@@ -7,9 +7,9 @@ copy cluster/$CLUSTER/cluster.nix /etc/nixos/cluster.nix
 copy cluster/$CLUSTER/node/$NIXHOST.nix /etc/nixos/node.nix
 copy cluster/$CLUSTER/node/$NIXHOST.site.nix /etc/nixos/site.nix
 
-cmd mkdir -p /var/lib/wgautomesh
-write_pass deuxfleurs/cluster/$CLUSTER/wgautomesh_gossip_secret /var/lib/wgautomesh/gossip_secret
 copy nix/wgautomesh.nix /etc/nixos/wgautomesh.nix
+cmd mkdir -p /var/lib/deuxfleurs
+write_pass deuxfleurs/cluster/$CLUSTER/wgautomesh_gossip_secret /var/lib/deuxfleurs/wgautomesh_gossip_secret
 
 if [ "$CLUSTER" = "staging" ]; then
 	copy nix/nomad-driver-nix2.nix /etc/nixos/nomad-driver-nix2.nix

nix/deuxfleurs.nix

@@ -207,18 +207,19 @@ in
     };
     services.wgautomesh = {
       enable = true;
-      interface = "wg0";
-      gossipPort = 1666;
-      gossipSecretFile = "/var/lib/wgautomesh/gossip_secret";
-      persistFile = "/var/lib/wgautomesh/state";
-      upnpForwardPublicPort = 
-        if clusterNodeCfg.endpoint != null then
-          strings.toInt (lists.last (split ":" clusterNodeCfg.endpoint))
-        else null;
-      peers = attrValues (mapAttrs (hostname: { publicKey, endpoint, address, ... }: {
-        inherit address endpoint;
-        pubkey = publicKey;
-      }) cfg.clusterNodes);
+      gossipSecretFile = "/var/lib/deuxfleurs/wgautomesh_gossip_secret";
+      settings = {
+        interface = "wg0";
+        gossip_port = 1666;
+        upnp_forward_external_port =
+          if clusterNodeCfg.endpoint != null then
+            strings.toInt (lists.last (split ":" clusterNodeCfg.endpoint))
+          else null;
+        peers = attrValues (mapAttrs (hostname: { publicKey, endpoint, address, ... }: {
+          inherit address endpoint;
+          pubkey = publicKey;
+        }) cfg.clusterNodes);
+      };
     };
     # Old code for wg-quick, we can use this as a fallback if we fail to make wgautomesh work
     # systemd.services."wg-quick-wg0".after = [ "unbound.service" ];

nix/wgautomesh.nix

@@ -7,123 +7,159 @@ in
 
 { lib, config, pkgs, ... }:
 with lib;
-let 
+let
   cfg = config.services.wgautomesh;
+  settingsFormat = pkgs.formats.toml { };
+  configFile =
+    # Have to remove nulls manually as TOML generator will not just skip key
+    # if value is null
+    settingsFormat.generate "wgautomesh-config.toml"
+      (filterAttrs (k: v: v != null)
+        (mapAttrs
+          (k: v:
+            if k == "peers"
+            then map (e: filterAttrs (k: v: v != null) e) v
+            else v)
+          cfg.settings));
+  runtimeConfigFile =
+    if cfg.enableGossipEncryption
+    then "/run/wgautomesh/wgautomesh.toml"
+    else configFile;
 in
-  with builtins;
-  {
-    options.services.wgautomesh = {
-      enable = mkEnableOption "wgautomesh";
-      logLevel = mkOption {
-        type = types.enum [ "trace" "debug" "info" "warn" "error" ];
-        default = "info";
-        description = "wgautomesh log level (trace/debug/info/warn/error)";
-      };
-      interface = mkOption {
-        type = types.str;
-        description = "Wireguard interface to manage";
-      };
-      gossipPort = mkOption {
-        type = types.port;
-        description = "wgautomesh gossip port";
-      };
-      gossipSecretFile = mkOption {
-        type = types.nullOr types.str;
-        description = "File containing the gossip secret encryption key";
-      };
-      persistFile = mkOption {
-        type = types.nullOr types.str;
-        description = "Path where to persist known peer addresses";
-      };
-      lanDiscovery = mkOption {
-        type = types.bool;
-        default = true;
-        description = "Enable discovery using LAN broadcast";
-      };
-      openFirewall = mkOption {
-        type = types.bool;
-        default = true;
-        description = "Automatically open gossip port in firewall";
-      };
-      upnpForwardPublicPort = mkOption {
-        type = types.nullOr types.port;
-        default = null;
-        description = "Public port number to try to redirect to this machine using UPnP IGD";
-      };
-      peers = mkOption {
-        type = types.listOf (types.submodule {
-          options = {
-            pubkey = mkOption {
-              type = types.str;
-              description = "Wireguard public key";
-            };
-            address = mkOption {
-              type = types.str;
-              description = "Wireguard peer address";
-            };
-            endpoint = mkOption {
-              type = types.nullOr types.str;
-              description = "bootstrap endpoint";
-            };
+{
+  options.services.wgautomesh = {
+    enable = mkEnableOption (mdDoc "the wgautomesh daemon");
+    logLevel = mkOption {
+      type = types.enum [ "trace" "debug" "info" "warn" "error" ];
+      default = "info";
+      description = mdDoc "wgautomesh log level.";
+    };
+    enableGossipEncryption = mkOption {
+      type = types.bool;
+      default = true;
+      description = mdDoc "Enable encryption of gossip traffic.";
+    };
+    gossipSecretFile = mkOption {
+      type = types.path;
+      description = mdDoc ''
+        File containing the shared secret key to use for gossip encryption.
+        Required if `enableGossipEncryption` is set.
+      '';
+    };
+    enablePersistence = mkOption {
+      type = types.bool;
+      default = true;
+      description = mdDoc "Enable persistence of Wireguard peer info between restarts.";
+    };
+    openFirewall = mkOption {
+      type = types.bool;
+      default = true;
+      description = mdDoc "Automatically open gossip port in firewall (recommended).";
+    };
+    settings = mkOption {
+      type = types.submodule {
+        freeformType = settingsFormat.type;
+        options = {
+          interface = mkOption {
+            type = types.str;
+            description = mdDoc ''
+              Wireguard interface to manage (it is NOT created by wgautomesh, you
+              should use another NixOS option to create it such as
+              `networking.wireguard.interfaces.wg0 = {...};`).
+            '';
+            example = "wg0";
           };
-        });
-        description = "wgautomesh peer list";
+          gossip_port = mkOption {
+            type = types.port;
+            description = mdDoc ''
+              wgautomesh gossip port, this MUST be the same number on all nodes in
+              the wgautomesh network.
+            '';
+            default = 1666;
+          };
+          lan_discovery = mkOption {
+            type = types.bool;
+            default = true;
+            description = mdDoc "Enable discovery of peers on the same LAN using UDP broadcast.";
+          };
+          upnp_forward_external_port = mkOption {
+            type = types.nullOr types.port;
+            default = null;
+            description = mdDoc ''
+              Public port number to try to redirect to this machine's Wireguard
+              daemon using UPnP IGD.
+            '';
+          };
+          peers = mkOption {
+            type = types.listOf (types.submodule {
+              options = {
+                pubkey = mkOption {
+                  type = types.str;
+                  description = mdDoc "Wireguard public key of this peer.";
+                };
+                address = mkOption {
+                  type = types.str;
+                  description = mdDoc ''
+                    Wireguard address of this peer (a single IP address, multliple
+                    addresses or address ranges are not supported).
+                  '';
+                  example = "10.0.0.42";
+                };
+                endpoint = mkOption {
+                  type = types.nullOr types.str;
+                  description = mdDoc ''
+                    Bootstrap endpoint for connecting to this Wireguard peer if no
+                    other address is known or none are working.
+                  '';
+                  default = null;
+                  example = "wgnode.mydomain.example:51820";
+                };
+              };
+            });
+            default = [ ];
+            description = mdDoc "wgautomesh peer list.";
+          };
+        };
       };
+      default = { };
+      description = mdDoc "Configuration for wgautomesh.";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.wgautomesh.settings = {
+      gossip_secret_file = mkIf cfg.enableGossipEncryption "$CREDENTIALS_DIRECTORY/gossip_secret";
+      persist_file = mkIf cfg.enablePersistence "/var/lib/wgautomesh/state";
     };
 
-    config = mkIf cfg.enable ( 
-    let
-      peerDefs = map (peer:
-        let endpointDef = if peer.endpoint == null then ""
-        else ''endpoint = "${peer.endpoint}"'';
-        in
-        ''
-          [[peers]]
-          pubkey = "${peer.pubkey}"
-          address = "${peer.address}"
-          ${endpointDef}
-        '') cfg.peers;
-      extraDefs = (if cfg.lanDiscovery then ["lan_discovery = true"] else [])
-        ++ (if (cfg.gossipSecretFile != null)
-          then [''gossip_secret_file = "${cfg.gossipSecretFile}"''] else [])
-        ++ (if (cfg.persistFile != null)
-          then [''persist_file = "${cfg.persistFile}"''] else [])
-        ++ (if (cfg.upnpForwardPublicPort != null)
-          then [''upnp_forward_external_port = ${toString cfg.upnpForwardPublicPort}''] else []);
-      configfile = pkgs.writeText "wgautomesh.toml" ''
-        interface = "${cfg.interface}"
-        gossip_port = ${toString cfg.gossipPort}
-        ${concatStringsSep "\n" extraDefs}
+    systemd.services.wgautomesh = {
+      path = [ pkgs.wireguard-tools ];
+      environment = { RUST_LOG = "wgautomesh=${cfg.logLevel}"; };
+      description = "wgautomesh";
+      serviceConfig = {
+        Type = "simple";
 
-        ${concatStringsSep "\n" peerDefs}
-        '';
-    in {
-      systemd.services.wgautomesh = {
-        enable = true;
-        path = [ pkgs.wireguard-tools ];
-        environment = {
-          RUST_LOG = "wgautomesh=${cfg.logLevel}";
-        };
-        description = "wgautomesh";
-        serviceConfig = {
-          Type = "simple";
+        ExecStart = "${wgautomesh}/bin/wgautomesh ${runtimeConfigFile}";
+        Restart = "always";
+        RestartSec = "30";
+        LoadCredential = mkIf cfg.enableGossipEncryption [ "gossip_secret:${cfg.gossipSecretFile}" ];
 
-          ExecStart = "${wgautomesh}/bin/wgautomesh ${configfile}";
-          Restart = "always";
-          RestartSec = "30";
+        ExecStartPre = mkIf cfg.enableGossipEncryption [
+          ''${pkgs.envsubst}/bin/envsubst \
+              -i ${configFile} \
+              -o ${runtimeConfigFile}''
+        ];
 
-          ExecStartPre = [ "+${pkgs.coreutils}/bin/chown wgautomesh /var/lib/wgautomesh/gossip_secret" ];
-
-          DynamicUser = true;
-          User = "wgautomesh";
-          StateDirectory = "wgautomesh";
-          StateDirectoryMode = "0700";
-          AmbientCapabilities = "CAP_NET_ADMIN";
-          CapabilityBoundingSet = "CAP_NET_ADMIN";
-        };
-        wantedBy = [ "multi-user.target" ];
+        DynamicUser = true;
+        StateDirectory = "wgautomesh";
+        StateDirectoryMode = "0700";
+        RuntimeDirectory = "wgautomesh";
+        AmbientCapabilities = "CAP_NET_ADMIN";
+        CapabilityBoundingSet = "CAP_NET_ADMIN";
       };
-      networking.firewall.allowedUDPPorts = mkIf cfg.openFirewall [ cfg.gossipPort ];
-    });
-  }
-  
+      wantedBy = [ "multi-user.target" ];
+    };
+    networking.firewall.allowedUDPPorts =
+      mkIf cfg.openFirewall [ cfg.settings.gossip_port ];
+  };
+}