So everyone is talking about cloudflare tunnels and I decided to give it a shot.

However, I find the learning curve quite hard and would really appreciate a short introduction into how they work and how do I set them up…

In my current infrastructure I am running a reverse proxy with SSL and Authentik, but nothing is exposed outside. I access my network via a VPN but would like to try out and consider CF. Might be easier for the family.

How does authentication work? Is it really a secure way to expose internal services?

Thanks!

  • Meow.tar.gz
    3•1 year ago

    In effect, Cloudflare would give protection against DDoS attacks before requests would even hit your servers. That much said you can implement mitigations on the reverse proxy itself. One example would be fail2ban.

    I’m sure there are additional steps that you can take. I’m not a fan of Cloudflare because their free offering has some caveats and violating these could be problematic. I have a cloud VPS with a WireGuard tunnel back to my server. I don’t have to do anything ugly like port forwarding. The cloud VPS runs NGINX as a reverse proxy. It’s a relatively simple and effective setup.

    • operatorOP
      1•1 year ago

      Thanks! How do you handle that with internal DNS? I suppose you’d need to setup the exact same proxies on the internal and external server, and local DNS handles which one my domain it’s being resolved to?

      • Meow.tar.gz
        1•1 year ago

        Right now the internal DNS I use has a TLD of .lan but that’s pretty much for my personal convenience. I access my websites by their FQDN internally with no issue. So I am not sure what your tring to achieve. Mind elaborating?

        • operatorOP
          1•1 year ago

          Of course! So in order to get maximum speed on your services, you wanna use a direct internal route when you’re inside your net. My understanding is, that when using an external cloud VPS with a proxy, local clients go through unnecessary routing…

          Local request --out--> external VPS (proxy) --request data from internal--> receive data on external proxy --send back--> local client

          So what I am saying, all requests are unnecessarily routed through the external VPS. So one would have to create an exact duplicate reverse proxy internally to avoid leaving the net. When accessing domain.com, the internal DNS returns the local proxy IP, when outside you receive the cloud VPS IP.

          Or am I missing something?

          Thank you for taking the time!

          • Meow.tar.gz
            1•1 year ago

            I have not converted my home network to use split-brain yet and that’s because I only just recently got Let’s Encrypt to work with the DNS-01 challenge which verifies domain ownership via a TXT record. Now that the DNS-01 challenge works perfectly, I can use split-brain DNS to resolve my example.com requests to internal IP addresses. What I am currently doing is as follows and it is inefficient and ugly!

            Local request ---> Internet --> VPS Proxy --> WireGuard tunnel --> Local Server --> WireGuard tunnel -> VPS Proxy -> Internet --> Local origin

            Now that I have Let’s Encrypt working using the DNS-01 challenge, there will be significantly less latency. It should look something like this:

            Local request --> Local DNS Server --> Local Server --> Local request
                                         |
                                         --> Local Server --> WireGuard Tunnel --> Internet

            I hope this is helpful! This will reduce the amount of locally generated traffic that must transit the VPN tunnel bi-directionally.

          • Meow.tar.gz
            1•1 year ago

            I just decided to go ahead and implement split-brain DNS this evening and it works perfectly. What are you using for your internal DNS server? If it is Unbound, the one that I am using, I can share my config with you. After implementing this, the speed of my services when being accessed from my internal network sped up by an order of magnitude. I shoulda done this earlier. 😆

            • operatorOP
              1•1 year ago

              That be amazing! I am currently not using anything (took down my homelab a while back) and planning on completely starting over fresh now.

              I am most likely going with unbound! So if you could, that be great!

              • Meow.tar.gz
                2•1 year ago

                Here is a sample configuration that should work for you:

                server:
        interface: 127.0.0.1
        interface: 192.168.1.1
        do-udp: yes
        do-tcp: yes
        do-not-query-localhost: no
        verbosity: 1
        log-queries: yes

        access-control: 0.0.0.0/0 refuse
        access-control-view: 127.0.0.0/8 example
        access-control-view: 192.168.1.0/24 example

        hide-identity: yes
        hide-version: yes
        tcp-upstream: yes

remote-control:
        control-enable: yes
        control-interface: /var/run/unbound.sock

view:
        name: "example"
        local-zone: "example.com." inform
        local-data: "example.com. IN A 192.168.1.2"
        local-data: "www IN CNAME example.com."
        local-data: "another.example.com. IN A 192.168.1.3"

forward-zone:
        name: "."
        forward-addr: 8.8.8.8
        forward-addr: 8.8.4.4

                What makes the split-brain DNS work is if the request for resolution comes from the localhost or from inside your network, it will first go to the view section to see if there is any pertinent local data. So if you do a query from your home network, on say, example.com, it will return your internal IP address which in this case is 192.168.1.2

                  • Meow.tar.gz
                    1•1 year ago

                    Sure! Let me know how it goes. If you need to do something more complex for internal DNS records for more than just A records, then look at the unbound.conf man page for stub zones. If you need something even more flexible than stub zones, you can use Unbound as a full authoritative DNS server with auth-zones. As far as I know auth-zones can even do zone transfers AXFR style which is cool!