feat: create and extract fork script

.gitignore

@@ -25,3 +25,5 @@ go.work.sum
 out
 
 contrib/bitcoind-data
+
+contrib/fork-*

contrib/bitcoin-mock.md

@@ -53,17 +53,37 @@ docker exec -it bitcoind-node /bin/bash
 Then you can generate a block:
 
 ```sh
-bitcoin-cli -regtest generate <number-block>
+bitcoin-cli -regtest -generate <number-block>
 ```
 
 If RPC params are required, you can provide them:
 
 ```sh
-bitcoin-cli -regtest -rpcuser=user -rpcpassword=password generate
+bitcoin-cli -regtest -rpcuser=user -rpcpassword=password -generate <number-block>
 ```
 
 More information in [developer.bitcoin.org -> testing](https://developer.bitcoin.org/examples/testing.html).
 
+### Create BTC fork for testing
+
+In a few cases, we must create a BTC fork for testing. The `create-fork.sh` script helps you do this. We provide two functions:
+
+#### Create fork
+
+Creates a new fork starting at the latest block in the snapshot data.
+
+```sh
+./create-fork.sh create <fork-name> <number-block>
+```
+
+#### Extract fork
+
+Extracts any block between a specified range. This command below returns the list of block headers in this range.
+
+```sh
+./create-fork.sh extract <fork-name> <start> <end>
+```
+
 ### Reference
 
 - [Running Bitcoind with ZMQ](https://bitcoindev.network/accessing-bitcoins-zeromq-interface/)

contrib/create-fork.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+
+# Create fork
+function createFork() {
+    forkName="./fork-"$1
+    forkLength=$2
+
+    cp -rf ./bitcoind-snapshot/ $forkName
+    BITCOIND_DATA=$forkName docker-compose up -d
+    docker exec -it bitcoind-node bitcoin-cli -generate $forkLength
+    docker-compose down
+}
+
+# Extract block between range 
+function extractFork() {
+    forkName="./fork-"$1
+    start=$2
+    end=$3
+
+    BITCOIND_DATA=$forkName docker-compose up -d
+    docker exec -it bitcoind-node bitcoin-cli -generate $forkLength
+
+    for ((i=$start; i<=$end; i++)); do
+	hash=$(docker exec -it bitcoind-node bitcoin-cli getblockhash $i | tr -d "\r\n")
+	docker exec -it bitcoind-node bitcoin-cli getblockheader $hash false
+    done
+    docker-compose down
+}
+
+
+case "$1" in
+  create)
+      createFork $2 $3
+    ;;
+  extract)
+      extractFork $2 $3 $4
+    ;;
+  *)
+    echo "Invalid option."
+    exit 1
+    ;;
+esac

contrib/docker-compose.yaml

@@ -5,7 +5,7 @@ services:
     image: kylemanna/bitcoind@sha256:2400e64960457b22be55299a2d7fa2aaa217f3dfc4afb84387e5511fe8ce5055
     # restart: unless-stopped
     volumes:
-      - ./bitcoind-data:/bitcoin/.bitcoin
+      - ${BITCOIND_DATA:-./bitcoind-data}:/bitcoin/.bitcoin
     ports:
       # regtest ports
       - 127.0.0.1:28331:28331 # zmq sequence