How can I get notified when money has been sent to a particular Bitcoin address on a local regtest network?

Question

I want to programmatically detect whenever someone sends Bitcoin to some address. This happens on a local testnet which I start using this docker-compose.yml file.

Once the local testnet runs, I create a new address using

docker exec -it minimal-crypto-exchange_node_1 bitcoin-cli getnewaddress

Let's say it returns 2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181.

I put this address into the following Java code:

import org.bitcoinj.core.Address;
import org.bitcoinj.core.Coin;
import org.bitcoinj.core.NetworkParameters;
import org.bitcoinj.core.Transaction;
import org.bitcoinj.wallet.Wallet;
import org.bitcoinj.wallet.listeners.WalletCoinsReceivedEventListener;

public class WalletObserver {
    public void init() {
        final NetworkParameters netParams = NetworkParameters.fromID(NetworkParameters.ID_REGTEST);

        try {
            final Wallet wallet = Wallet.createBasic(netParams);

            wallet.addWatchedAddress(Address.fromString(netParams, "2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181"));

            wallet.addCoinsReceivedEventListener(new WalletCoinsReceivedEventListener() {
                @Override
                public void onCoinsReceived(final Wallet wallet, final Transaction transaction, final Coin prevBalance, final Coin newBalance) {
                    System.out.println("Heyo!");
                }
            });
        }
        catch (Exception exception) {
            exception.printStackTrace();
        }
    }
}

Then I start the Java application with this class.

Then I send some test Bitcoin to the address in question:

% docker exec -it minimal-crypto-exchange_node_1 bitcoin-cli sendtoaddress 2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181 0.5
068c377bab961356ad9a3919229a764aa929711c68aefd5dbd4c7c348eef3406

If I go to http://localhost:3002/tx/068c377bab961356ad9a3919229a764aa929711c68aefd5dbd4c7c348eef3406, I see that the transaction details.

However, the breakpoint in the listener (onCoinsReceived method) never activates.

How do I need to modify my code and/or the commands I use to send test BTC so that whenever money is received by that account, onCoinsReceived method is called? Is there a place where I can tell Wallet or NetworkParameters that I want to connect to localhost?

I am using version 0.15.10 of bitcoinj-core.

Update 1:

I modified docker-compose.yml and added following port mappings:

    ports:
      - "51001:50001"
      - "51002:50002"
      - "19001:19001"
      - "19000:19000"
      - "28332:28332"

Then I rewrote the init method so that I can connect to localhost and specify the port:

public class WalletObserver {
    public void init() {
        final LocalTestNetParams netParams = new LocalTestNetParams();
        netParams.setPort(50001);
        try {
            final WalletAppKit kit = new WalletAppKit(netParams, new File("."), "_minimalCryptoExchangeBtcWallet");
            kit.setAutoSave(true);
            kit.connectToLocalHost();

            kit.startAsync();
            kit.awaitRunning(); // I never get past this point
            kit.peerGroup().addPeerDiscovery(new DnsDiscovery(netParams));
            kit.wallet().addWatchedAddress(Address.fromString(netParams, "2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181"));

            kit.wallet().addCoinsReceivedEventListener(new WalletCoinsReceivedEventListener() {
                @Override
                public void onCoinsReceived(final Wallet wallet, final Transaction transaction, final Coin prevBalance, final Coin newBalance) {
                    System.out.println("Heyo!");
                }
            });
        }
        catch (Exception exception) {
            exception.printStackTrace();
        }
    }

LocalTestNetParams allows to specify the port:

package com.dpisarenko.minimalcryptoexchange.logic.btc;

import org.bitcoinj.params.RegTestParams;

public class LocalTestNetParams extends RegTestParams {
    public void setPort(final int newPort) {
        this.port = newPort;
    }
}

I tried all of the aforementioned ports in netParams.setPort(50001);.

In all cases I get the following messages after kit.awaitRunning();:

22:16:34.245 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Attempting connection to [10.10.1.218]:50001     (0 connected, 1 pending, 1 max)
22:16:34.265 [NioClientManager] WARN  org.bitcoinj.net.NioClientManager - Failed to connect with exception: java.net.ConnectException: Connection refused
java.net.ConnectException: Connection refused
    at java.base/sun.nio.ch.Net.pollConnect(Native Method)
    at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:579)
    at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:820)
    at org.bitcoinj.net.NioClientManager.handleKey(NioClientManager.java:64)
    at org.bitcoinj.net.NioClientManager.run(NioClientManager.java:122)
    at com.google.common.util.concurrent.AbstractExecutionThreadService$1$2.run(AbstractExecutionThreadService.java:66)
    at com.google.common.util.concurrent.Callables$4.run(Callables.java:119)
    at org.bitcoinj.utils.ContextPropagatingThreadFactory$1.run(ContextPropagatingThreadFactory.java:51)
    at java.base/java.lang.Thread.run(Thread.java:830)
22:16:34.267 [NioClientManager] INFO  org.bitcoinj.core.PeerGroup - [10.10.1.218]:50001: Peer died      (0 connected, 0 pending, 1 max)
22:16:34.267 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Peer discovery took 21.84 μs and returned 0 items from 0 discoverers
22:16:34.269 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Waiting 1502 ms before next connect attempt to [10.10.1.218]:50001
22:16:35.776 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Attempting connection to [10.10.1.218]:50001     (0 connected, 1 pending, 1 max)
22:16:35.778 [NioClientManager] WARN  org.bitcoinj.net.NioClientManager - Failed to connect with exception: java.net.ConnectException: Connection refused
java.net.ConnectException: Connection refused
    at java.base/sun.nio.ch.Net.pollConnect(Native Method)
    at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:579)
    at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:820)
    at org.bitcoinj.net.NioClientManager.handleKey(NioClientManager.java:64)
    at org.bitcoinj.net.NioClientManager.run(NioClientManager.java:122)
    at com.google.common.util.concurrent.AbstractExecutionThreadService$1$2.run(AbstractExecutionThreadService.java:66)
    at com.google.common.util.concurrent.Callables$4.run(Callables.java:119)
    at org.bitcoinj.utils.ContextPropagatingThreadFactory$1.run(ContextPropagatingThreadFactory.java:51)
    at java.base/java.lang.Thread.run(Thread.java:830)
22:16:35.778 [NioClientManager] INFO  org.bitcoinj.core.PeerGroup - [10.10.1.218]:50001: Peer died      (0 connected, 0 pending, 1 max)
22:16:35.779 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Peer discovery took 8.752 μs and returned 0 items from 0 discoverers

10.10.1.218 seems to be generated by InetAddress.getLocalHost() in org.bitcoinj.kits.WalletAppKit#connectToLocalHost:

    public WalletAppKit connectToLocalHost() {
        try {
            InetAddress localHost = InetAddress.getLocalHost();
            return this.setPeerNodes(new PeerAddress(this.params, localHost, this.params.getPort()));
        } catch (UnknownHostException var2) {
            throw new RuntimeException(var2);
        }
    }

Update 1:

I tried to use network_mode: "host".

If I add it to node as in

  node:
    image: ulamlabs/bitcoind-custom-regtest:latest
    network_mode: "host"

I get the following error when I run docker-compose up -d:

minimal-crypto-exchange % docker-compose up -d
Creating network "minimal-crypto-exchange_default" with the default driver
Creating minimal-crypto-exchange_postgres_1  ... done
Creating minimal-crypto-exchange_geth_1     ...
Creating minimal-crypto-exchange_node_1     ... done
Creating minimal-crypto-exchange_electrumx_1 ...
Creating minimal-crypto-exchange_electrumx_1 ... error

ERROR: for minimal-crypto-exchange_electrumx_1  Cannot start service electrumx: driver fail
Creating minimal-crypto-exchange_geth_1      ... done
f68d0f25a0512399877bc55434513def810649e4fcf31a5a88ca3292d34): Error starting userland proxy: listen tcp4 0.0.0.0:28332: bind: address already in use
Creating minimal-crypto-exchange_blockscout_1 ... done

ERROR: for electrumx  Cannot start service electrumx: driver failed programming external connectivity on endpoint minimal-crypto-exchange_electrumx_1 (8eaa4f68d0f25a0512399877bc55434513def810649e4fcf31a5a88ca3292d34): Error starting userland proxy: listen tcp4 0.0.0.0:28332: bind: address already in use
ERROR: Encountered errors while bringing up the project.

If I add it to electrumx part as in

  electrumx:
    image: lukechilds/electrumx:latest
    network_mode: "host"

I get another error:

minimal-crypto-exchange % docker-compose up -d
minimal-crypto-exchange_postgres_1 is up-to-date
minimal-crypto-exchange_geth_1 is up-to-date
Recreating minimal-crypto-exchange_node_1 ...
Recreating minimal-crypto-exchange_node_1 ... done
Recreating minimal-crypto-exchange_electrumx_1 ...

ERROR: for minimal-crypto-exchange_electrumx_1  "host" network_mode is incompatible with port_bindings

ERROR: for electrumx  "host" network_mode is incompatible with port_bindings
Traceback (most recent call last):
  File "docker-compose", line 3, in <module>
  File "compose/cli/main.py", line 81, in main
  File "compose/cli/main.py", line 203, in perform_command
  File "compose/metrics/decorator.py", line 18, in wrapper
  File "compose/cli/main.py", line 1186, in up
  File "compose/cli/main.py", line 1166, in up
  File "compose/project.py", line 697, in up
  File "compose/parallel.py", line 108, in parallel_execute
  File "compose/parallel.py", line 206, in producer
  File "compose/project.py", line 679, in do
  File "compose/service.py", line 579, in execute_convergence_plan
  File "compose/service.py", line 499, in _execute_convergence_recreate
  File "compose/parallel.py", line 108, in parallel_execute
  File "compose/parallel.py", line 206, in producer
  File "compose/service.py", line 494, in recreate
  File "compose/service.py", line 612, in recreate_container
  File "compose/service.py", line 330, in create_container
  File "compose/service.py", line 939, in _get_container_create_options
  File "compose/service.py", line 1014, in _get_container_host_config
  File "docker/api/container.py", line 598, in create_host_config
  File "docker/types/containers.py", line 338, in __init__
docker.errors.InvalidArgument: "host" network_mode is incompatible with port_bindings
[44262] Failed to execute script docker-compose

Update 2:

If I comment out port bindings as in

  electrumx:
    image: lukechilds/electrumx:latest
    network_mode: host
    links:
      - node
# Port settings see https://github.com/ulamlabs/bitcoind-custom-regtest
#    ports:
#      - "51001:50001"
#      - "51002:50002"
#      - "19001:19001"
#      - "19000:19000"
#      - "28332:28332"

and run docker-compose up -d I get

 % docker-compose up -d
Creating network "minimal-crypto-exchange_default" with the default driver
Creating minimal-crypto-exchange_geth_1 ...
Creating minimal-crypto-exchange_postgres_1  ... done
Creating minimal-crypto-exchange_node_1     ... done
Creating minimal-crypto-exchange_electrumx_1 ... error
Creating minimal-crypto-exchange_geth_1      ... done
ERROR: for minimal-crypto-exchange_electrumx_1  Cannot create container for service electrumx: conflicting options: host type networking can't be used with links. This would result in undefined behavior
Creating minimal-crypto-exchange_blockscout_1 ... done

ERROR: for electrumx  Cannot create container for service electrumx: conflicting options: host type networking can't be used with links. This would result in undefined behavior
ERROR: Encountered errors while bringing up the project.

Update 3: I assume that the root of the error is that in my Java code I try to connect to the ElectrumX server instead of the actual Bitcoin node (node in docker-compose.yml).

Update 4:

I changed docker-compose.yml as follows:

  node:
    image: ulamlabs/bitcoind-custom-regtest:latest
# For ports used by node see
# https://github.com/ulamlabs/bitcoind-custom-regtest/blob/master/bitcoin.conf
    ports:
      - "19001:19001"
      - "19000:19000"
      - "28332:28332"
  electrumx:
    image: lukechilds/electrumx:latest
    links:
      - node
# Port settings see https://github.com/ulamlabs/bitcoind-custom-regtest
    ports:
      - "51001:50001"
      - "51002:50002"
#      - "19001:19001"
#      - "19000:19000"
#      - "28332:28332"

Now I am getting different errors (full log available here):

11:33:51.865 [NioClientManager] INFO  org.bitcoinj.core.PeerGroup - [192.168.10.208]:19000: Peer died      (0 connected, 0 pending, 1 max)
11:33:51.865 [NioClientManager] INFO  org.bitcoinj.core.PeerGroup - Not yet setting download peer because there is no clear candidate.
11:33:51.865 [NioClientManager] DEBUG org.bitcoinj.core.BitcoinSerializer - Received 168 byte 'alert' message: 60010000000000000000000000ffffff7f00000000ffffff7ffeffff7f01ffffff7f00000000ffffff7f00ffffff7f002f555247454e543a20416c657274206b657920636f6d70726f6d697365642c2075706772616465207265717569726564004630440220653febd6410f470f6bae11cad19c48413becb1ac2c17f908fd0fd53bdc3abd5202206d0e9c96fe88d4a0f01ed9dedae2b6f9e00da94cad0fecaae66ecf689bf71b50
11:33:51.866 [PeerGroup Thread] INFO  org.bitcoinj.core.PeerGroup - Waiting 999 ms before next connect attempt to [127.0.0.1]:19000
11:33:51.866 [NioClientManager] DEBUG org.bitcoinj.core.Peer - Received alert from peer Peer{[192.168.10.208]:19000, version=70015, subVer=/Satoshi:0.19.1(bitcore)/, services=1033 (NETWORK, WITNESS, NETWORK_LIMITED), time=2021-11-06 11:33:52, height=5}: URGENT: Alert key compromised, upgrade required
11:33:51.867 [NioClientManager] WARN  org.bitcoinj.net.ConnectionHandler - Error handling SelectionKey: java.nio.channels.CancelledKeyException 
java.nio.channels.CancelledKeyException: null
    at java.base/sun.nio.ch.SelectionKeyImpl.ensureValid(SelectionKeyImpl.java:71)
    at java.base/sun.nio.ch.SelectionKeyImpl.readyOps(SelectionKeyImpl.java:130)
    at java.base/java.nio.channels.SelectionKey.isWritable(SelectionKey.java:377)
    at org.bitcoinj.net.ConnectionHandler.handleKey(ConnectionHandler.java:244)
    at org.bitcoinj.net.NioClientManager.handleKey(NioClientManager.java:86)
    at org.bitcoinj.net.NioClientManager.run(NioClientManager.java:122)
    at com.google.common.util.concurrent.AbstractExecutionThreadService$1$2.run(AbstractExecutionThreadService.java:66)
    at com.google.common.util.concurrent.Callables$4.run(Callables.java:119)
    at org.bitcoinj.utils.ContextPropagatingThreadFactory$1.run(ContextPropagatingThreadFactory.java:51)
    at java.base/java.lang.Thread.run(Thread.java:830)

Update 5:

Someone suggested (in a now removed comment) that in the output of the application there is this Peer does not support bloom filtering message:

11:32:43.482 [NioClientManager] INFO  org.bitcoinj.core.Peer - Peer{[127.0.0.1]:19000, version=70015, subVer=/Satoshi:0.19.1(bitcore)/, services=1033 (NETWORK, WITNESS, NETWORK_LIMITED), time=2021-11-06 11:32:43, height=4}: Peer does not support bloom filtering.

So I tried to fork the original image and change the bitcoin.conf file to enable Bloom filtering:

peerbloomfilters=1

When I run docker build -t mentiflectax/bitcoind-custom-regtest:latest . I get the following error message (part of remaining output can be found here):

#13 922.4 g++: fatal error: Killed signal terminated program cc1plus
#13 922.4 compilation terminated.
#13 922.4 make[2]: *** [Makefile:8044: libbitcoin_server_a-init.o] Error 1
#13 922.4 make[2]: *** Waiting for unfinished jobs....
#13 965.8 make[2]: Leaving directory '/bitcoin-0.19.1/src'
#13 965.8 make[1]: *** [Makefile:13765: all-recursive] Error 1
#13 965.9 make[1]: Leaving directory '/bitcoin-0.19.1/src'
#13 965.9 make: *** [Makefile:776: all-recursive] Error 1
------
executor failed running [/bin/sh -c tar -xzf *.tar.gz     && cd bitcoin-${BITCOIN_VERSION}     && sed -i 's/consensus.nSubsidyHalvingInterval = 150/consensus.nSubsidyHalvingInterval = 210000/g' src/chainparams.cpp     && ./autogen.sh     && ./configure LDFLAGS=-L`ls -d /opt/db`/lib/ CPPFLAGS=-I`ls -d /opt/db`/include/     --prefix=/opt/bitcoin     --disable-man     --disable-tests     --disable-bench     --disable-ccache     --with-gui=no     --enable-util-cli     --with-daemon     && make -j4     && make install     && strip /opt/bitcoin/bin/bitcoin-cli     && strip /opt/bitcoin/bin/bitcoind]: exit code: 2

Update 6: The correct port seems to be 19000.

If I use port 19001, I get following errors after kit.awaitRunning():

INFO  org.bitcoinj.core.PeerSocketHandler - [127.0.0.1]:19001: Timed out

Full log output is available here.

Answer 1

I haven't tested your full setup with electrumx and the ethereum stuff present in your docker-compose file, but regarding your problem, the following steps worked properly, and I think it will do as well in your complete setup.

I ran with docker a bitcoin node based in the ulamlabs/bitcoind-custom-regtest:latest image you provided:

docker run -p 18444:19000 -d ulamlabs/bitcoind-custom-regtest:latest

As you can see, I exposed the image internal port 19000 as the default port for RegTestParams, 18444. From the point of view of our client, with this setup, basically it will look like as if we were running the bitcoin daemon in the host. Using your LocalTestNetParams class and providing the port 19000 as you indicated should do the trick as well.

Then, according to the feedback you provided in the question, I manually edited the daemon configuration of the bitcoin node in /root/.bitcoin/bitcoin.conf using bash and vi:

docker exec -it 0aa2e863cd9927 bash

And included the following configuration:

peerbloomfilters=1

After restart the container, I got a new address:

docker exec -it 0aa2e863cd9927 bitcoin-cli -regtest getnewaddress

Let's assume that the new address is the one you provided in the question:

2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181

Then, as suggested in the Bitcoin documentation, in order to avoid an insufficient funds error, I generated 101 blocks to this address:

docker exec -it 0aa2e863cd9927 bitcoin-cli -regtest generatetoaddress 101 2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181 

I used generatetoaddress and not generate because since Bitcoin 0.19.0 the option is no longer valid.

Next, I prepared a simple Java program, based in the information you provided and this example from the Bitcoinj library documentation:

import java.io.File;

import org.bitcoinj.core.Address;
import org.bitcoinj.core.NetworkParameters;
import org.bitcoinj.kits.WalletAppKit;
import org.bitcoinj.params.RegTestParams;

public class Kit {

  public static void main(String[] args) {
    Kit kit  = new Kit();
    kit.run();
  }

  private synchronized void run(){
    NetworkParameters params = RegTestParams.get();
    WalletAppKit kit = new WalletAppKit(params, new File("."), "walletappkit-example");
    kit.connectToLocalHost();

    kit.startAsync();
    kit.awaitRunning();

    kit.wallet().addWatchedAddress(Address.fromString(params, "2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181"));

    kit.wallet().addCoinsReceivedEventListener((wallet, tx, prevBalance, newBalance) -> {
      System.out.println("-----> coins resceived: " + tx.getTxId());
    });

    while (true) {
      try {
        this.wait(2000);
      } catch (InterruptedException e) {
        e.printStackTrace();
      }
    }
  }
}

I used a simple while loop to keep the problem running; of course, if will be probably unnecessary in an actual setup as it seems you are using Spring Boot.

Then, if you send some bitcoins to this address:

docker exec -it 0aa2e863cd9927 bitcoin-cli -regtest sendtoaddress 2N23tWAFEtBtTgxNjBNmnwzsiPdLcNek181 0.00001
0f972642713c72ae0fe03fe51818b9ea4d483720b69b90e795f35eb80a587c26

The listener should be invoked:

2021-11-09 23:51:20.537 INFO  [NioClientManager][Wallet] Received a pending transaction 0f972642713c72ae0fe03fe51818b9ea4d483720b69b90e795f35eb80a587c26 that spends 0.00 BTC from our own wallet, and sends us 0.00001 BTC
2021-11-09 23:51:20.537 INFO  [NioClientManager][Wallet] commitTx of 0f972642713c72ae0fe03fe51818b9ea4d483720b69b90e795f35eb80a587c26
...
2021-11-09 23:51:20.537 INFO  [NioClientManager][Wallet] ->pending: 0f972642713c72ae0fe03fe51818b9ea4d483720b69b90e795f35eb80a587c26
2021-11-09 23:51:20.537 INFO  [NioClientManager][Wallet] Estimated balance is now: 0.00001 BTC
-----> coins resceived: 0f972642713c72ae0fe03fe51818b9ea4d483720b69b90e795f35eb80a587c26
2021-11-09 23:51:20.538 INFO  [NioClientManager][WalletFiles] Saving wallet; last seen block is height 165, date 2021-11-09T22:50:48Z, hash 23451521947bc5ff098c088ae0fc445becca8837d39ee8f6dd88f2c47ad5ac23
2021-11-09 23:51:20.543 INFO  [NioClientManager][WalletFiles] Save completed in 4.736 ms

There is still a problem you mentioned that I haven't had the opportunity to test, and it is creating a new Docker image in which the peerbloomfilters configuration would be configured properly without modifying the actual container state. I think the compilation problem you indicated could be related to this issue, basically, that the container didn't have enough resources to perform the process. If you are using macOS and Docker for Mac, try tweaking the amount of memory available to your containers, it may be of help. A change in the base alpine image used can motivate the problem also. I will try digging into the issue as well.