Setup Cloudflare Tunnel

Create and configure a Cloudflare Tunnel to expose internal services to the internet without opening firewall ports.

Parameter Handling

If parameters are missing from $ARGUMENTS, use mcp_question to gather them:

mcp_question({
  questions: [
    {
      question: "What should the tunnel be named?",
      header: "Tunnel Name",
      options: [
        { label: "Enter name...", description: "e.g., myservice (used for config references)" }
      ]
    },
    {
      question: "Which host will run cloudflared?",
      header: "Host",
      options: [
        { label: "pilaster (Recommended)", description: "Main web services host" },
        { label: "monolith", description: "Infrastructure services" },
        { label: "zenith", description: "AI/GPU workloads" }
      ]
    },
    {
      question: "What public domain should expose the service?",
      header: "Domain",
      options: [
        { label: "Enter domain...", description: "e.g., myservice.meskill.farm" }
      ]
    }
  ]
})

Expected $ARGUMENTS format: <tunnel_name> <hostname> <domain>

• Example: myservice pilaster myservice.meskill.farm

Architecture

Internet → Cloudflare Edge → Tunnel (cloudflared) → Caddy → Service

Steps

1. Authenticate with Cloudflare

cloudflared tunnel login

Opens browser for authentication, creates ~/.cloudflared/cert.pem.

2. Create the Tunnel

cloudflared tunnel create <tunnel-name>

Outputs:

• Tunnel ID: UUID like 9b4d96ca-4911-46d3-979e-38f3d6dae733
• Credentials: ~/.cloudflared/<tunnel-id>.json

3. Encrypt Credentials

# Unlock agenix
agenix-helper unlock

# Create directory
mkdir -p hosts/<hostname>/files/cloudflared

# Encrypt cert.pem (one per host, reusable)
agenix edit -i ~/.cloudflared/cert.pem \
            hosts/<hostname>/files/cloudflared/cert.pem.age

# Encrypt tunnel credentials
agenix edit -i ~/.cloudflared/<tunnel-id>.json \
            hosts/<hostname>/files/cloudflared/<tunnel-name>.json.age

# Clean up unencrypted files
rm ~/.cloudflared/cert.pem ~/.cloudflared/<tunnel-id>.json

# Rekey
agenix rekey -a

4. Configure NixOS

Create or update hosts/<hostname>/cloudflared.nix:

{config, ...}: {
  services.cloudflared = {
    enable = true;
    tunnels = {
      "<tunnel-id>" = {
        credentialsFile = "${config.age.secrets.<hostname>_cloudflared_<tunnel>.path}";
        ingress = {
          "<service>.meskill.farm" = "https://<service>-int.meskill.farm";
        };
        default = "http_status:404";
      };
    };
  };

  # cert.pem for tunnel management
  age.secrets.<hostname>_cloudflared_cert_pem = {
    rekeyFile = ./files/cloudflared/cert.pem.age;
    path = "/etc/cloudflared/cert.pem";
    mode = "644";
  };

  # Tunnel credentials
  age.secrets.<hostname>_cloudflared_<tunnel> = {
    rekeyFile = ./files/cloudflared/<tunnel-name>.json.age;
    mode = "644";
  };
}

5. Update Caddyfile

Both internal and external domains:

<service>-int.meskill.farm <service>.meskill.farm {
  reverse_proxy <container>:<port>
}

6. Configure DNS

# Internal domain (for Caddy)
cfcli --domain meskill.farm --type CNAME add <service>-int <hostname>.meskill.farm

# External domain (proxied through Cloudflare tunnel)
cfcli --domain meskill.farm --type CNAME --activate add <service> <tunnel-id>.cfargotunnel.com

7. Deploy

just remote-rebuild <hostname>

Existing Tunnels

Troubleshooting

Tunnel not connecting

systemctl status cloudflared-tunnel-<tunnel-id>
journalctl -u cloudflared-tunnel-<tunnel-id> -f

Verify credentials exist

ls -la /run/agenix/ | grep cloudflared

Example

/setup-cloudflare-tunnel myservice pilaster myservice.meskill.farm