i have found this reference very useful https://mynixos.com/options/

yeah proxmox is not necessary unless you need lots of separate instances to play around with

this is my container config for element/matrix podman containers do not run as root so you have to get the file privileges right on the volumes mapped into the containers. i used top to find out what user the services were running as. you can see there are some settings there where you can change the user if you are having permissions problems

{ pkgs, modulesPath, ... }:

{

  imports = [
    (modulesPath + "/virtualisation/proxmox-lxc.nix")
  ];

  security.pki.certificateFiles = [ "/etc/ssl/certs/ca-certificates.crt" ];

  system.stateVersion = "23.11";
  system.autoUpgrade.enable = true;
  system.autoUpgrade.allowReboot = false;

  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 14d";
  };

  services.openssh = {
    enable = true;
    settings.PasswordAuthentication = true;
  };

  users.users.XXXXXX = {
    isNormalUser = true;
    home = "/home/XXXXXX";
    extraGroups = [ "wheel" ];
    shell = pkgs.zsh;
  };

  programs.zsh.enable = true;

  environment.etc = {
    "fail2ban/filter.d/matrix-synapse.local".text = pkgs.lib.mkDefault (pkgs.lib.mkAfter ''
      [Definition]
      failregex = .*POST.* - <HOST> - 8008.*\n.*\n.*Got login request.*\n.*Failed password login.*
                  .*POST.* - <HOST> - 8008.*\n.*\n.*Got login request.*\n.*Attempted to login as.*\n.*Invalid username or password.*
    '');
  };

  services.fail2ban = {
    enable = true;
    maxretry = 3;
    bantime = "10m";
    bantime-increment = {
      enable = true;
      multipliers = "1 2 4 8 16 32 64";
      maxtime = "168h";
      overalljails = true;
    };
    jails = {
      matrix-synapse.settings = {
        filter = "matrix-synapse";
        action = "%(known/action)s";
        logpath = "/srv/logs/synapse.json.log";
        backend = "auto";
        findtime = 600;
        bantime  = 600;
        maxretry = 2;
      };
    };
  };

  virtualisation.oci-containers = {
    containers = {

      postgres = {
        autoStart = false;
        environment = {
          POSTGRES_USER = "XXXXXX";
          POSTGRES_PASSWORD = "XXXXXX";
          LANG = "en_US.utf8";
        };
        image = "docker.io/postgres:14";
        ports = [ "5432:5432" ];
        volumes = [
          "/srv/postgres:/var/lib/postgresql/data"
        ];
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--pull=newer"
        ];
      };

      synapse = {
        autoStart = false;
        environment = {
          LANG = "C.UTF-8";
#          UID="0";
#          GID="0";
        };
 #       user = "1001:1000";
        image = "ghcr.io/element-hq/synapse:latest";
        ports = [ "8008:8008" ];
        volumes = [
          "/srv/synapse:/data"
        ];
        log-driver = "json-file";
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--log-opt" "max-size=10m" "--log-opt" "max-file=1" "--log-opt" "path=/srv/logs/synapse.json.log"
          "--pull=newer"
        ];
        dependsOn = [ "postgres" ];
      };

      element = {
        autoStart = true;
        image = "docker.io/vectorim/element-web:latest";
        ports = [ "8009:80" ];
        volumes = [
          "/srv/element/config.json:/app/config.json"
        ];
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--pull=newer"
        ];
#        dependsOn = [ "synapse" ];
      };

      call = {
        autoStart = true;
        image = "ghcr.io/element-hq/element-call:latest-ci";
        ports = [ "8080:8080" ];
        volumes = [
          "/srv/call/config.json:/app/config.json"
        ];
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--pull=newer"
        ];
      };

      livekit = {
        autoStart = true;
        image = "docker.io/livekit/livekit-server:latest";
        ports = [ "7880:7880" "7881:7881" "50000-60000:50000-60000/udp" "5349:5349" "3478:3478/udp" ];
        cmd = [ "--config" "/etc/config.yaml" ];
        entrypoint = "/livekit-server";
        volumes = [
          "/srv/livekit:/etc"
        ];
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--pull=newer"
        ];
      };

      livekitjwt = {
        autoStart = true;
        image = "ghcr.io/element-hq/lk-jwt-service:latest-ci";
        ports = [ "7980:8080" ];
        environment = {
          LK_JWT_PORT = "8080";
          LIVEKIT_URL = "wss://livekit.xxxxxx.dynu.net/";
          LIVEKIT_KEY = "XXXXXX";
          LIVEKIT_SECRET = "XXXXXX";
        };
        entrypoint = "/lk-jwt-service";
        extraOptions = [
          "--label" "io.containers.autoupdate=registry"
          "--pull=newer"
        ];
      };

    };
  };

}

this is my nginx config for my element/matrix services

as you can see i am using a proxmox NixOS with an old 23.11 nix channel but i’m sure the config can be used in other NixOS environments

{ pkgs, modulesPath, ... }:

{
  imports = [
    (modulesPath + "/virtualisation/proxmox-lxc.nix")
  ];

  security.pki.certificateFiles = [ "/etc/ssl/certs/ca-certificates.crt" ];

  system.stateVersion = "23.11";
  system.autoUpgrade.enable = true;
  system.autoUpgrade.allowReboot = true;

  nix.gc = {
    automatic = true;
    dates = "weekly";
    options = "--delete-older-than 14d";
  };

  networking.firewall.allowedTCPPorts = [ 80 443 ];

  services.openssh = {
    enable = true;
    settings.PasswordAuthentication = true;
  };

  users.users.XXXXXX = {
    isNormalUser = true;
    home = "/home/XXXXXX";
    extraGroups = [ "wheel" ];
    shell = pkgs.zsh;
  };

  programs.zsh.enable = true;

  security.acme = {
    acceptTerms = true;
    defaults.email = "XXXXXX@yahoo.com";
  };

  services.nginx = {
    enable = true;

    virtualHosts._ = {
      default = true;
      extraConfig = "return 500; server_tokens off;";
    };

    virtualHosts."XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;

      locations."/_matrix/federation/v1" = {
        proxyPass = "http://192.168.10.131:8008/";
        extraConfig = "client_max_body_size 300M;" +
          "proxy_set_header X-Forwarded-For $remote_addr;" +
          "proxy_set_header Host $host;" +
          "proxy_set_header X-Forwarded-Proto $scheme;";
      };

      locations."/" = {
        extraConfig = "return 302 https://element.xxxxxx.dynu.net/;";
      };

      extraConfig = "proxy_http_version 1.1;";
    };

    virtualHosts."matrix.XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;

      extraConfig = "proxy_http_version 1.1;";

      locations."/" = {
        proxyPass = "http://192.168.10.131:8008/";
        extraConfig = "client_max_body_size 300M;" +
          "proxy_set_header X-Forwarded-For $remote_addr;" +
          "proxy_set_header Host $host;" +
          "proxy_set_header X-Forwarded-Proto $scheme;";
      };
    };

    virtualHosts."element.XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;
      locations."/" = {
        proxyPass = "http://192.168.10.131:8009/";
        extraConfig = "proxy_set_header X-Forwarded-For $remote_addr;";
      };
    };

    virtualHosts."call.XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;
      locations."/" = {
        proxyPass = "http://192.168.10.131:8080/";
        extraConfig = "proxy_set_header X-Forwarded-For $remote_addr;";
      };
    };

    virtualHosts."livekit.XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;

      locations."/wss" = {
        proxyPass = "http://192.168.10.131:7881/";
#        proxyWebsockets = true;
        extraConfig = "proxy_http_version 1.1;" +
          "proxy_set_header X-Forwarded-For $remote_addr;" +
          "proxy_set_header Host $host;" +
          "proxy_set_header Connection \"upgrade\";" +
          "proxy_set_header Upgrade $http_upgrade;";
      };

      locations."/" = {
        proxyPass = "http://192.168.10.131:7880/";
#        proxyWebsockets = true;
        extraConfig = "proxy_http_version 1.1;" +
          "proxy_set_header X-Forwarded-For $remote_addr;" +
          "proxy_set_header Host $host;" +
          "proxy_set_header Connection \"upgrade\";" +
          "proxy_set_header Upgrade $http_upgrade;";
      };
    };

    virtualHosts."livekit-jwt.XXXXXX.dynu.net" = {
      enableACME = true;
      addSSL = true;
      locations."/" = {
        proxyPass = "http://192.168.10.131:7980/";
        extraConfig = "proxy_set_header X-Forwarded-For $remote_addr;";
      };
    };

    virtualHosts."turn.XXXXXX.dynu.net" = {
      enableACME = true;
      http2 = true;
      addSSL = true;
      locations."/" = {
        proxyPass = "http://192.168.10.131:5349/";
      };
    };

  };
}

you only need to reboot Nix when something low level has changed. i honestly don’t know where that line is drawn so i reboot quite a lot when i’m setting up a Nix server and then hardly reboot it at all from then on even with auto-updates running oh and if i make small changes to the services i just run sudo nixos-rebuild switch and don’t reboot

Johnson & Johnson