blog/source/_posts/cloudflare-argo-nixos.md at bdc4a74c79071166c0df2094018a85b6add3545d

7.5 KiB

Raw Blame History

title

excerpt

date

updated

Setup

Grab the cloudflared binary from Cloudflare and make it executable without installing it to "/usr/bin".

./cloudflared tunnel login

cert.pem will be generated in the default cloudflared directory.

Create a new tunnel

This step can be done on your local machine, the actual installation on a server can come later.

./cloudflared tunnel create mytunnel

A new UUID.json will be generated in the default cloudflared directory.

Configure the tunnel

Create a new yml file.

tunnel: mytunnel
credentials-file: /var/lib/argoWeb/uuid.json

# Optional
# loglevel: warn

ingress:
  - hostname: mdleom.com
    service: http://localhost:4430
  - hostname: www.mdleom.com
    service: http://localhost:4430
  - service: http_status:404

Alternatively, HTTPS can be reached directly if enabled.

tunnel: mytunnel
credentials-file: /var/lib/argoWeb/uuid.json
originRequest:
  matchSNItoHost: true

# Optional
# loglevel: warn

ingress:
  - hostname: mdleom.com
    service: https://localhost:4430
  - hostname: www.mdleom.com
    service: https://localhost:4430
  - service: http_status:404

The last entry is intentionally left without a hostname key as required by cloudflared. Usually, it's configured with http_status:404 so cloudflared returns that status if there is no matching destination hostname for an incoming request. This can happen when say you have a foo.example.com DNS record that points to the daemon, so incoming request does reach the daemon, but either you forgot to configure the daemon to route the traffic to the actual foo.example.com web server or the web server is not running at all. In that case, the daemon will return a HTTP 404 status.

Configure NixOS

Create a new user and group named "argoWeb" in the server.

  users = {
    users = {
      argoWeb = {
        home = "/var/lib/argoWeb";
        createHome = true;
        isSystemUser = true;
        group = "argoWeb";
      };
    };

    groups = {
      caddyProxy.members = [ "argoWeb" ];
    };
  };

Once argoWeb is created via nixos-rebuild, upload and move the json file (located in the default cloudflared directory) to "/var/lib/argoWeb" folder. chown argoWeb:argoWeb and chmod 600 that file.

Then, Create a new nix file; in this case, I'm using "/etc/caddy/" folder (where I put other *.nix files):

{ config, lib, pkgs, ... }:

with lib;

let
  cfg = config.services.argoWeb;
in {
  options.services.argoWeb = {
    enable = mkEnableOption "Cloudflare Tunnel";

    config = mkOption {
      default = "/etc/caddy/argoWeb.yml";
      type = types.str;
      description = "Path to cloudflared config";
    };

    dataDir = mkOption {
      default = "/var/lib/argoWeb";
      type = types.path;
      description = ''
        The data directory, for storing credentials.
      '';
    };

    package = mkOption {
      default = pkgs.cloudflared;
      defaultText = "pkgs.cloudflared";
      type = types.package;
      description = "cloudflared package to use.";
    };
  };

  config = mkIf cfg.enable {
    systemd.services.argoWeb = {
      description = "Cloudflare Tunnel";
      after = [ "network-online.target" ];
      wants = [ "network-online.target" ]; # systemd-networkd-wait-online.service
      wantedBy = [ "multi-user.target" ];
      serviceConfig = {
        ExecStart = "${cfg.package}/bin/cloudflared --config ${cfg.config} --no-autoupdate tunnel run";
        Type = "simple";
        User = "argoWeb";
        Group = "argoWeb";
        Restart = "on-failure";
        RestartSec = "5s";
        NoNewPrivileges = true;
        LimitNPROC = 512;
        LimitNOFILE = 1048576;
        PrivateTmp = true;
        PrivateDevices = true;
        ProtectHome = true;
        ProtectSystem = "full";
        ReadWriteDirectories = cfg.dataDir;
      };
    };
  };
}

Move the yml file to "/etc/caddy/" and set both yml and nix files to be chown root:root and chmod 644.

Configure Caddy

Bind the web server to localhost and optionally enable the tls. client_auth should not be configured as Cloudflare Tunnel does not support it and does not offer security benefit for a localhost web server.

mdleom.com:4430 www.mdleom.com:4430 {
  bind 127.0.0.1 [::1]

  tls /var/lib/caddyProxy/mdleom.com.pem /var/lib/caddyProxy/mdleom.com.key {
    protocols tls1.3
  }
}

Restart/reload Caddy for the changed config to take effect.

Custom package (optional)

If your NixOS instance is IPv6-only, you may want to use a {% post_link custom-package-nixos-module 'custom package' %}. pkgs.cloudflared is installed by compiling the source from the GitHub repo, instead of using a cached binary from Nix repo. cloudflared's license restricts the distribution of binary, hence the need of source compilation. However, GitHub doesn't support IPv6 yet, so we need to clone its repo to other Git repo that supports IPv6 and then download it from there.

Start cloudflared

  require = [
    /etc/caddy/argoWeb.nix
  ];
  # cloudflared is not distributed via a free software license
  nixpkgs.config.allowUnfree = true;
  services.argoWeb = {
    enable = true;
    config = "/etc/caddy/argoWeb.yml";
    # custom package
    # package = pkgs.callPackage (import /etc/caddy/cloudflared-custom.nix) { };
  };

Create a CNAME record

The last step is to create a new DNS record to CNAME the relevant hostname to UUID.cfargotunnel.com . Existing A/CNAME must be removed beforehand since a hostname cannot have both A and CNAME records at the same time, nor having two similar CNAMEs.

7.5 KiB Raw Blame History