I’ve been vaguely aware of BitCoin for a decade but never really dug into it until recently, as a direct result of my interest in the Podcasting 2.0 team.
My goals were:
- Minimise expenditure and transaction fees
- Use existing hardware and open-source software
- Setup a functional lightning node to both make and accept payments
I’m the proud owner of a Synology, and it can run docker, and you can run BitCoin and Lightning in Docker containers? Okay then…this should be easy enough, right?
BitCoin Node Take 1
I set up the kylemanna/bitcoind docker on my Synology and started it syncing to the Mainnet blockchain. About a week later and I was sitting at 18% complete and averaging 1.5% per day and dropping. Reading up on this and the problem was two-fold: validating the blockchain is a CPU and HDD/SSD intensive task and my Synology had neither. I threw more RAM at it (3GB out of the 4GB it had) with no difference in performance, set the CPU restrictions to give the Docker the most performance possible with no difference and basically ran out of levers to pull.
I then learned it’s possible to copy a blockchain from one device to another and the Raspberry Pi’s sold as your own private node come with the blockchain pre-synced (up to the point they’re shipped) so they don’t take too long to catch up to the front of the chain. I then downloaded BitCoin Core for MacOS and set it running. After two days it had finished (much better) and I copied the directories to the Synology only to find that the settings on BitCoin Core were to “prune” the blockchain after validation, meaning the entire blockchain was no longer stored on my Mac, and the docker container would need to start over.
So I disabled pruning on the Mac, and started again. The blockchain was about 300GB (so I was told) and with my 512GB SSD on my MBP I thought that would be enough, but alas no, as the amount of free space diminished at a rapid rate of knots, I madly off-loaded and deleted what I could finishing with about 2GB to spare and the entire blockchain and associated files weighed in at 367GB.
Transferring them to the Synology and firing up the Docker…it worked! Although it had to revalidate the 6 most recent blocks (taking about 26 minutes EVERY time you restarted the BitCoin docker) it sprang to life nicely. I had a BitCoin node up and running!
Lightning Node Take 1
There are several docker containers to choose from, the two most popular seemed to be LND and c-Lightning. Without understanding the differences I went with the container that was said to be more lightweight and work better on a Synology: c-Lightning.
Later I was to discover that more plugins, applications, GUIs, relays (Sphinx for example) only work with LND and require LND Macaroons, which c-Lightning doesn’t support. Not only that design decisions by the c-Lightning developers to only permit single connections between nodes makes building liquidity problematic when you’re starting out. (More on that in another post someday…)
After messing around with RPC for the cLightning docker to communicate with the KyleManna Bitcoind docker, I realised that I needed to install ZMQ support since RPC Username and Password authentication were being phased out in preference for a token authentication through a shared folder.
I was so frustrated at losing 26 minutes every time I had to change a single setting in the Bitcoin docker, and in an incident overnight both dockers crashed, didn’t restart and then took over a day to catch up to the blockchain again. I had decided more or less at this point to give up on it.
SSD or don’t bother
Interestingly my oldest son pointed out that all of the kits for sale used SSDs for the Bitcoin data storage - even the cheapest versions. A bit more research and it turns out that crunching through the blockchain is less of a CPU intensive exercise and more of a data store read/write intensive exercise. I had a 512GB Samsung USB 3.0 SSD laying around and in a fit of insanity decided to try connecting it to the Synology’s rear port, shift the entire contents of the docker shared folders (that contained all of the blocks and indexes) to that SSD and try it again.
Oh My God it was like night and day.
Both docker containers started, synced and were running in minutes. Suddenly I was interested again!
Bitcoin Node Take 2
With renewed interest I returned to my previous headache - linking the docker containers properly. The LNCM/Bitcoind docker had precompiled support for ZMQ and it was surprisingly easy to set up the docker shared file to expose the token I needed for authentication with the cLightning docker image. It started up referencing the same docker folder (now mounted on the SSD) and honestly, seemed to “just work” straight up. So far so good.
Lightning Node Take 2
This time I went for the more-supported LND, and picked one that was quite popular by Guggero, and also spun it up rather quickly. My funds on my old cLightning node would simply have to remain trapped until I could figure out how to recover them in future.
The instructions I had read all related to TestNet, and advised not to use money you weren’t prepared to lose. I set myself a starting budget of $40 AUD and tried to make this work. Using the Breez app on iOS and their integration with MoonPay I managed to convert about 110k Sats. The next problem was getting them from Breez to my own Node and my attempts with Lightning failed with “no route.” (I learned later I needed channels…d’uh) Sending via BitCoin was the only option. “On-chain” they call it. This cost me a lot of Sats, but I finally had some Sats on my Node.
BitCoin has a few quirky little problems. One interesting one is that a single BitCoin is worth a LOT of money - currently 1 BTC = $62,000.00 AUD. So it’s not a practical measure and hence BitCoin is more commonly referred to in Satoshi’s which are 1/100,000,000th of a BitCoin. BitCoin is a crypto-currency which is transacted on the BitCoin blockchain, via the BitCoin network. Lightning is a Layer 2 network that also deals in BitCoin but in smaller amounts, peer to peer connected via channels and because the values are much smaller is regularly transacted in values of Satoshi’s.
Everything you do requires Satoshi’s (SATS). It costs SATS to fund a channel. It costs SATS to close a channel. I couldn’t find out how to determine the minimum amount of Sats needed to open a channel without first opening one via the command line. I only had a limited number of SATs to play with so I had to choose carefully. Most channels wanted 10,000 or 20,000 but I managed a find a few that only required 1,000. The initial thought was to open as many channels as you could then make some transactions and your inbound liquidity will improve as others in the network transact.
Services exist to help build that inbound liquidity, without which, you can’t accept payments from anyone else. Another story for a future post.
Anything On-Chain Is Slow and Expensive
For a technology that’s supposed to be reducing fees overall, Lightning seems to cost you a bit up-front to get into it, and anytime you want to shuffle things around, it costs SATS. I initially bought into it wishing to fund my own node and try for that oft-touted “self-soverignty” of BitCoin, but to achieve that you have to invest some money to get started. In the end however I hadn’t invested enough because my channels I opened didn’t allow inbound payments.
I asked some people to open some channels to me and give me some inbound liquidity however not a single one of them successfully opened. My BitCoin and Lightning experiment had ground to a halt, once again.
At first I experimented with TOR, then by publishing on an external IP address, port-forwarding to expose the Lightning external access port 9735 to allow incoming connections. Research into why highlighted that I needed to recreate my dockers but connect them to a custom Docker network and then resync the containers otherwise the open channel attempts would continue to fail.
I did that and it still didn’t work.
Then I stumbled across the next idea: you needed to modify the Synology Docker DSM implementation to allow direct mounting of the Docker images without them being forced through a Double-NAT. Doing so was likely to impact my other, otherwise perfectly happily running Dockers.
Playing with BitCoin today feels like programming COBOL for a bank in the 80s
Did you know that COBOL is behind nearly half of all financial transactions in 2017? Yes and the world is gradually ripping it out (thankfully).
IDENTIFICATION DIVISION. PROGRAM-ID. CONDITIONALS. DATA DIVISION. WORKING-STORAGE SECTION. *> I'm not joking, Lightning-cli and Bitcoin-cli make me think I'm programming for a bank 01 NUM1 SATSJOHNHAS 0(0). PROCEDURE DIVISION. MOVE 20000 TO NUM1. IF NUM1 > 0 THEN DISPLAY 'YAY I HAZ 20000 SATS!' END-IF *> I'd like to make all of transactions using the command line, just like when I do normal banking...oh wait... EVALUATE TRUE WHEN SATS = 0 DISPLAY 'NO MORE SATS NOW :(' END-EVALUATE. STOP RUN.
There is no doubt there’s a bit geek-elitism amongst many of the people involved with BitCoin. Comments like “Don’t use a GUI, to understand it you MUST use the command line…” reminds me of those that whined about the Macintosh in 1984 having a GUI. A “real” computer used DOS. OMFG seriously?
A real financial system is as painless for the user as possible. Unbeknownst to me, I’d chosen a method that was perhaps the least advisable: the wrong hardware running the wrong software, running a less-compatible set of dockers and my conclusion was that setting up your own Node that you control is not easy.
It’s not intuitive either and it will make you think about things like inbound liquidity that you never thought you’d need to know, since you’re geek - not an investment banker. I suppose the point is that owning your own bank means you have to learn a bit about how a bank needs to work and that takes time and effort.
If you’re happy to just pay someone else to build and operate a node for you then that’s fine and that’s just what you’re doing today with any bank account. I spent weeks learning just how much I don’t want to be my own bank - thank you very much, or at least I didn’t want to using the equipment that I had laying about and living in the Terminal.
Synology as a Node Verdict
Docker was not reliable enough either. In some instances I would modify a single dockers configuration file and restart the container only get “Docker API failed”. Sometimes I could recover by picking the Docker Container I thought had caused the failure (most likely the one I modified but not always) by clearing the container and restarting it.
Other times I had to completely reboot the Synology to recover it and sometimes I had to do both for Docker to restart. Every restart of the Bitcoin Container and there would go another half an hour restarting and then the container would “go backwards” and be 250 blocks behind taking a further 24-48 hours of resynchronising with the blockchain before the Lightning Container could then resynchronise with it. All the while the node was offline.
Unless your Synology is running SSDs, has at least 8GB of RAM, is relatively new and you don’t mind hacking your DSM Docker installation, you could probably make it work, but it’s horses for courses in the end. If you have an old PC laying about then use that. If you have RAM and SSD on your NAS then build a VM rather than use Docker, maybe. Or better yet, get a Raspberry Pi and have a dedicated little PC that can do the work.
Don’t Do What I Did
Money is Gone
The truth is in an attempt to get incoming channel opens working, I flicked between Bridge and Host and back again, opening different ports with Socks failed errors and finally gave up when after many hours the LND docker just wouldn’t connect via ZMQ any more.
And with that my $100 AUD investment is now stuck between two virtual wallets.
I will keep trying and report back but at this point my intention is to invest in a Raspberry Pi to run my own Node. I’ll let you know how that goes in due course.