> eth-private-net is a simple tool that allows you to quickly setup a three-node private Ethereum network running locally on your personal computer. The tool makes initializing, starting, and connecting nodes fast and easy. The network comes with three pre-made identities (Alice, Bob, and Lily) and a tutorial that walks you through simple actions like mining and transferring Ether, and culminates with the deployment and execution of a simple smart contract called FreeBeer.

> I wrote this tool because I found a lot of the Ethereum tooling opaque and difficult to understand. A lot of the information that I needed to know was scattered through the documentation, and there wasn't a single place that wrapped together the most instructive examples to build my understanding. Moreover, I wanted a tool that would allow me to repeatedly reinitialize a network from a known, clean state to help me experiment with building, deploying, and running smart contracts.

Exactly the kind of thing I've been looking for! Thank you tons.

>I wrote this tool because I found a lot of the Ethereum tooling opaque and difficult to understand.

Thank you, I don't feel alone now.

This is an amazingly well-written example! I have very little interest in Ethereum (or cryptocurrency in general) but your writeup made me want to try it out and play with it. I wish I had documentation this good for everything!

Thanks! We were doing some deep technical dives into ethereum and cryptocurrencies here at Initialized Capital (where I work) and I was getting frustrated that I couldn't get all of the moving pieces together in one place.

This tool / tutorial was something I threw together to prove to myself that I understood everything, but then turned into something that I thought some other people might be interested in playing with.

Question: how does it differ to testrpc + web3?

testrpc is more of a backend for developing and running tests for solidity smart contracts (e.g., Truffle recommends it as a backend for testing).

My project is more focused on getting people to use the actual ethereum tooling (geth), and for them to learn what's going on under the hood.

Here is a similarly great post if you'd like to get your feet wet on running the bitcoin network locally (via regtest mode):

https://witestlab.poly.edu/blog/get-rich-on-fake-bitcoins/

We at enuma.io has also wrote a blog post with similar goals but specifically for setting up a Proof of Authority chain:

http://blog.enuma.io/update/2017/08/29/proof-of-authority-et...

One small step towards a OCM. Thank you for this!

By OCM you mean a one-click miner?

Thank you man.

Lovely work!

Thanks for putting this together! I had been looking for something like this to get me started with Ethereum...

I've been going through the walkthrough and seem to have hit a snag. I have alice, bob, and lily all initialized and connected to each other as peers to form a three-node network, and have tried to have alice start mining. The "Generating DAG in progress" completed after 13 minutes (not 1 minute as you said it should, though I'm running Ubuntu on a virtual machine on my not-that-fast Surface Book which may explain this. After it completes, I see this message in the console:

DEBUG[09-08|12:27:59] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:28:03] Generating DAG in progress epoch=0 percentage=98 elapsed=12m39.760s INFO [09-08|12:28:09] Generating DAG in progress epoch=0 percentage=99 elapsed=12m46.488s INFO [09-08|12:28:09] Generated ethash verification cache epoch=0 elapsed=12m46.499s DEBUG[09-08|12:28:09] Failed to load old ethash dataset epoch=1 err="open /home/xxxxxx/.ethash/full-R23-290decd9548b62a8: no such file or directory" INFO [09-08|12:28:13] Generating ethash verification cache epoch=1 percentage=82 elapsed=3.088s INFO [09-08|12:28:13] Generated ethash verification cache epoch=1 elapsed=3.636s DEBUG[09-08|12:28:19] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s DEBUG[09-08|12:28:39] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:28:59] Generating DAG in progress epoch=1 percentage=0 elapsed=22.150s DEBUG[09-08|12:28:59] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s DEBUG[09-08|12:29:18] Couldn't add port mapping proto=tcp extport=40301 intport=40301 interface="UPnP or NAT-PMP" err="no UPnP or NAT-PMP router discovered" DEBUG[09-08|12:29:19] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:29:22] Generating DAG in progress epoch=1 percentage=1 elapsed=44.984s DEBUG[09-08|12:29:39] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:29:48] Generating DAG in progress epoch=1 percentage=2 elapsed=1m11.554s DEBUG[09-08|12:29:59] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:30:13] Generating DAG in progress epoch=1 percentage=3 elapsed=1m36.181s DEBUG[09-08|12:30:20] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|12:30:34] Generating DAG in progress epoch=1 percentage=4 elapsed=1m57.705s

I never see the "Successfully sealed new block" message and alice's ether value never increases; it seems like a new "generate DAG" step just begins. I also notice that in my .ethash directory I have two files: "full-R23-0000000000000000" and "full-R23-290decd9548b62a8", with the "000..." file last modified at 12:28 (the same time that the process completed" and the "290..." file getting updated later. I then let this complete to 100 percent (it took 34 minutes this time), and see the following:

INFO [09-08|13:02:48] Generating DAG in progress epoch=1 percentage=98 elapsed=34m11.249s DEBUG[09-08|13:03:04] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s INFO [09-08|13:03:14] Generating DAG in progress epoch=1 percentage=99 elapsed=34m37.494s INFO [09-08|13:03:14] Generated ethash verification cache epoch=1 elapsed=34m37.500s DEBUG[09-08|13:03:24] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s DEBUG[09-08|13:03:44] Recalculated downloader QoS values rtt=20s confidence=1.000 ttl=1m0s

Alice's ether value still hasn't increased. At this point I'm stumped as to what's going on. Any help to get me moving again would be greatly appreciated. Thanks!

Given that it took many minutes to generate the DAG, I'm wondering if your machine is a bit underpowered. You can make mining much easier by adjusting the difficulty parameter here (lower means faster mining): https://github.com/vincentchu/eth-private-net/blob/master/ge...

It was tuned to yield a block every 15 seconds or so on my laptop; may be slower or faster depending on how fast your machine is relative to mine.

Why though?