Why Yet Another Blockchain Explorer?

There are many already out there. I wrote this blockchain explorer to learn a. Elixir, b. Phoenix, and c. Blockchain

I couldn't have done it without https://github.com/pcorey/hello_blockchain to get me started

13 August 2018 - tested with Elixir 1.7.2, Erlang/OTP 21

You need to be running bitcoind:

start-bitcoind.sh regtest (twice)

start-bitcoind.sh testnet

or

start-bitcoind.sh mainnet

(The last of these runs a full node, and uses a lot of disk space - 200 Gb and counting)

If you are using regtest, the most economical choice, wait a few seconds, then run regenerate.sh to generate some blocks

For what regtest, testnet and mainnet mean, see https://dzone.com/articles/bitcoin-and-junit

Before doing the above, you need to copy at least bitcoin1.conf into your ~/.bitcoin folder

regtest mode

To do anything useful in regtest mode, you need at least two instances of bitcoind running

Copy bitcoin1.conf and bitcoin2.conf into your .bitcoin folder in your home directory

Of course, you should not use USERNAME and PASSWORD, which are in these files

You need to change these in your bitcoinN.conf files, and in config/config.exs

Create 'regtest' folders under the .bitcoin folder - at least $HOME/.bitcoin/regtest1 and $HOME/.bitcoin/regtest2

Start the first instance like this start-bitcoind.sh regtest 1 and the second like this start-bitcoind.sh regtest 2

further information

See https://github.com/bitcoin/bitcoin

See ubuntu-install.txt for installation on Linux

To start Phoenix:

• Install dependencies with mix deps.get
• Install Node.js dependencies with cd assets then
• npm install
• ./node_modules/brunch/bin/brunch build
• cd ..
• Start Phoenix with mix phx.server

Now visit localhost:4000 in a browser

On a Mac, your data is written in Library/Application Support/Bitcoin, unless you've specified a datadir (see start-bitcoin.sh)

You can turn it into a soft link pointing to a large (500 Gb+) external drive - which you probably will have to do if using testnet or mainnet, as the blockchain just keeps getting bigger. And this blockchain explorer keeps getting slower, causing tests to time out. A real production version would use a database, inserting each new block as its minted. Since the number of blocks is only in the millions, finding addresses etc. would be very fast.