From f03cafd49b48eabc4743b3a3791fd22f19cb0de1 Mon Sep 17 00:00:00 2001
From: Alex Auvolat <alex@adnab.me>
Date: Wed, 9 Feb 2022 12:09:49 +0100
Subject: Modularize and prepare to support multiple clusters

---
 nix/deuxfleurs.nix | 185 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 185 insertions(+)
 create mode 100644 nix/deuxfleurs.nix

(limited to 'nix')

diff --git a/nix/deuxfleurs.nix b/nix/deuxfleurs.nix
new file mode 100644
index 0000000..9b8013c
--- /dev/null
+++ b/nix/deuxfleurs.nix
@@ -0,0 +1,185 @@
+{ config, pkgs, ... }:
+
+let
+  cfg = config.deuxfleurs;
+in
+  with builtins;
+  with pkgs.lib;
+{
+  options.deuxfleurs = 
+    let wg_node = with types; submodule {
+      options = {
+        hostname = mkOption {
+          type = str;
+          description = "Host name";
+        };
+        IP = mkOption {
+          type = str;
+          description = "IP Address";
+        };
+        publicKey = mkOption {
+          type = str;
+          description = "Public key";
+        };
+        endpoint = mkOption {
+          type = nullOr str;
+          description = "Wireguard endpoint on the public Internet";
+        };
+      };
+    };
+  in
+  {
+    # Parameters that may vary between nodes
+    site_name = mkOption {
+      description = "Site (availability zone) on which this node is deployed";
+      type = types.str;
+    };
+    vpn_ip = mkOption {
+      description = "IP address of this node on the Wireguard VPN";
+      type = types.str;
+    };
+    vpn_listen_port = mkOption {
+      description = "Port for incoming Wireguard VPN connections";
+      type = types.port;
+    };
+    is_raft_server = mkOption {
+      description = "Make this node a RAFT server for the Nomad and Consul deployments";
+      type = types.bool;
+      default = false;
+    };
+
+    # Parameters common to all nodes
+    cluster_name = mkOption {
+      description = "Name of this Deuxfleurs deployment";
+      type = types.str;
+    };
+    cluster_nodes = mkOption {
+      description = "Nodes that are part of the cluster";
+      type = types.listOf wg_node;
+    };
+    admin_nodes = mkOption {
+      description = "Machines that are part of the Wireguard VPN for administration purposes";
+      type = types.listOf wg_node;
+    };
+    admin_accounts = mkOption {
+      description = "List of users having an admin account on cluster nodes, maps user names to a list of authorized SSH keys";
+      type = types.attrsOf (types.listOf types.str);
+    };
+  };
+
+  config = {
+    # Configure admin accounts on all nodes
+    users.users = builtins.mapAttrs (name: publicKeys: {
+      isNormalUser = true;
+      extraGroups = [ "wheel" ];
+      openssh.authorizedKeys.keys = publicKeys;
+    }) cfg.admin_accounts;
+
+    # Configure Wireguard VPN between all nodes
+    networking.wireguard.interfaces.wg0 = {
+      ips = [ "${cfg.vpn_ip}/16" ];
+      listenPort = cfg.vpn_listen_port;
+      privateKeyFile = "/root/wireguard-keys/private";
+      peers = map ({ publicKey, endpoint, IP, ... }: {
+        publicKey = publicKey;
+        allowedIPs = [ "${IP}/32" ];
+        endpoint = endpoint;
+        persistentKeepalive = 25;
+      }) (cfg.cluster_nodes ++ cfg.admin_nodes);
+    };
+
+    networking.firewall.allowedUDPPorts = [ cfg.vpn_listen_port ];
+
+    # Configure /etc/hosts to link all hostnames to their Wireguard IP
+    networking.extraHosts = builtins.concatStringsSep "\n" (map
+      ({ hostname, IP, ...}: "${IP} ${hostname}")
+      (cfg.cluster_nodes ++ cfg.admin_nodes));
+
+    # Enable Hashicorp Consul & Nomad
+    services.consul.enable = true;
+    services.consul.extraConfig =
+      (if cfg.is_raft_server
+      then {
+        server = true;
+        bootstrap_expect = 3;
+      }
+      else {}) //
+    {
+      datacenter = cfg.cluster_name;
+      node_meta = {
+        "site" = cfg.site_name;
+      };
+      ui = true;
+      bind_addr = cfg.vpn_ip;
+
+      ports.http = -1;
+      addresses.https = "0.0.0.0";
+      ports.https = 8501;
+
+      retry_join = map (node_info: node_info.IP) cfg.cluster_nodes;
+
+      ca_file = "/var/lib/consul/pki/consul-ca.crt";
+      cert_file = "/var/lib/consul/pki/consul2022.crt";
+      key_file = "/var/lib/consul/pki/consul2022.key";
+      verify_incoming = true;
+      verify_outgoing = true;
+      verify_server_hostname = true;
+    };
+
+    services.nomad.enable = true;
+    services.nomad.package = pkgs.nomad_1_1;
+    services.nomad.settings =
+      (if cfg.is_raft_server
+      then { server = {
+        enabled = true;
+        bootstrap_expect = 3;
+      }; }
+      else {}) //
+    {
+      region = cfg.cluster_name;
+      datacenter = cfg.site_name;
+      advertise = {
+        rpc = cfg.vpn_ip;
+        http = cfg.vpn_ip;
+        serf = cfg.vpn_ip;
+      };
+      consul = {
+        address = "localhost:8501";
+        ca_file = "/var/lib/nomad/pki/consul2022.crt";
+        cert_file = "/var/lib/nomad/pki/consul2022-client.crt";
+        key_file = "/var/lib/nomad/pki/consul2022-client.key";
+        ssl = true;
+      };
+      client = {
+        enabled = true;
+        network_interface = "wg0";
+        meta = {
+          "site" = cfg.site_name;
+        };
+      };
+      tls = {
+        http = true;
+        rpc = true;
+        ca_file = "/var/lib/nomad/pki/nomad-ca.crt";
+        cert_file = "/var/lib/nomad/pki/nomad2022.crt";
+        key_file = "/var/lib/nomad/pki/nomad2022.key";
+        verify_server_hostname = true;
+        verify_https_client = true;
+      };
+      plugin = [
+        {
+          docker = [
+            {
+              config = [
+                {
+                  volumes.enabled = true;
+                  allow_privileged = true;
+                }
+              ];
+            }
+          ];
+        }
+      ];
+    };
+  };
+}
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