Have you ever wanted to experiment with modifying the bitcoin source code?
This is the perfect way to dip your toes into bitcoin development.
I highly recommend running this inside a docker container.
This is a private, bitcoin, testnet-in-a-box. It's a fork of freewil/bitcoin-testnet-box that also allows you to build bitcoind and bitcoin-cli from source.
You must have bitcoind and bitcoin-cli installed on your system and in the
path unless running this within a Docker container
(see below).
The docker image will run two bitcoin nodes in the background and is meant to be attached to allow you to type in commands. The image also exposes the two JSON-RPC ports from the nodes if you want to be able to access them from outside the container.
(in case any missing dependencies, check https://github.com/bitcoin/bitcoin/blob/0.12/doc/build-unix.md)
$ docker run -ti --name btcdev -P -p 49020:19000 jimtou/bitcoinx:version2
Build the image as: cd /home/bitcoinx/BitcoinX ./autogen.sh ./configure LDFLAGS="-L/home/theusername/bitcoin/db4/lib/" CPPFLAGS="-I/home/theusername/bitcoin/db4/include/" make -s -j5
cd /home/bitcoinx/ /home/bitcoinx/BitcoinX/src/btc2d -datadir=1 -regtest -daemon
/home/bitcoinx/BitcoinX/src/btc2-cli -datadir=1 getinfo
This will start up two nodes using the two datadirs 1 and 2. They
will only connect to each other in order to remain an isolated private testnet.
Two nodes are provided, as one is used to generate blocks and it's balance
will be increased as this occurs (imitating a miner). You may want a second node
where this behavior is not observed.
Node 1 will listen on port 19000, allowing node 2 to connect to it.
Node 1 will listen on port 19001 and node 2 will listen on port 19011
for the JSON-RPC server.
$ make start
$ make getinfo
bitcoin-cli -datadir=1 getinfo
{
"version" : 90300,
"protocolversion" : 70002,
"walletversion" : 60000,
"balance" : 0.00000000,
"blocks" : 0,
"timeoffset" : 0,
"connections" : 1,
"proxy" : "",
"difficulty" : 0.00000000,
"testnet" : false,
"keypoololdest" : 1413617762,
"keypoolsize" : 101,
"paytxfee" : 0.00000000,
"relayfee" : 0.00001000,
"errors" : ""
}
bitcoin-cli -datadir=2 getinfo
{
"version" : 90300,
"protocolversion" : 70002,
"walletversion" : 60000,
"balance" : 0.00000000,
"blocks" : 0,
"timeoffset" : 0,
"connections" : 1,
"proxy" : "",
"difficulty" : 0.00000000,
"testnet" : false,
"keypoololdest" : 1413617762,
"keypoolsize" : 101,
"paytxfee" : 0.00000000,
"relayfee" : 0.00001000,
"errors" : ""
}
Normally on the live, real, bitcoin network, blocks are generated, on average, every 10 minutes. Since this testnet-in-box uses Bitcoin Core's (bitcoind) regtest mode, we are able to generate a block on a private network instantly using a simple command.
To generate a block:
$ make generate
To generate more than 1 block:
$ make generate BLOCKS=10
In order to create a balance that you can send to another address, you need to generate at least 100 blocks:
$ make generate BLOCKS=100
To send bitcoins that you've generated:
$ make send ADDRESS=mxwPtt399zVrR62ebkTWL4zbnV1ASdZBQr AMOUNT=10
After sending bitcoins (generated on node 1) to node 2, send them back to node 1. In order to do so you will need to get a new address for node 1. You can optionally specify an account on node 1 to associate the address with.
$ make address ACCOUNT=testwithdrawals
You first generate an address for node2:
$ make address2
bitcoin-cli -datadir=2 getnewaddress
mtRipU3BueyarTRcWsKjKXgGsUWMdcWDzD
We see an address for node2 is mtRipU3BueyarTRcWsKjKXgGsUWMdcWDzD. You can use your bitcoin client to send bitcoin to the address or you can send it from node1 using make send ADDRESS=mtRipU3BueyarTRcWsKjKXgGsUWMdcWDzD AMOUNT=1.5.
$ make stop
To clean up any files created while running the testnet and restore to the original state:
$ make clean
You can use the Bitcoin-QT to connect to this docker container's bitcoin nodes. This is how you can do it on a Mac:
# Example on a Mac
$ mkdir -p ~/localnet
$ /Applications/Bitcoin-Qt.app/Contents/MacOS/Bitcoin-Qt \
-regtest -dnsseed=0 -connect=dockerhost:49020 \
-datadir=./localnet/
# Example on Linux
$ mkdir -p ~/localnet
$ /path/to/bitcoin-qt \
-regtest -dnsseed=0 -connect=localhost:49020 \
-datadir=./localnet/
# Example on Windows
$ MKDIR $HOME\localnet
$ "C:\Program Files\Bitcoin\bitcoin-qt.exe" \
-regtest -dnsseed=0 -connect=dockerhost:49020 \
-datadir=$HOME/localnetThis assumes you are using port 49020 when you remapped your ports using docker
Note to Mac or Windows Users: dockerhost is typically 192.168.59.103, but this can change based on your Oracle VirtualBox settings. You can always check for the IP address by running boot2docker ip from the command line on Mac or Windows.
Another cool feature of this docker container is it comes pre-loaded with the bitcoin source code. I've taken the time to install all the libraries bitcoin needs to be built. So you can modify the bitcoin source code, compile it, and the run your local testnet to see if your changes work. Here's how you can do that:
cd ~/testnet/src- Use an editor (vim comes installed on this container) to modify the source code
cd ~/testnet/make build(this command stops bitcoind, rebuilds bitcoin, and then runs bitcoind again)
Note: it will ask you the password for the tester user because it needs to use sudo. The password is tester.
This testnet-box can be used with docker to run it in an isolated container.
Either pull the image:
docker pull poliver/bitcoin-dev-box
...or build it yourself from this directory:
docker build -t bitcoin-dev-box .