Bitcoind

Utility to run a regtest bitcoind process, useful in integration testing environment.

When the auto-download feature is selected by activating one of the version feature, such as 25_1 for bitcoin core 25.1, starting a regtest node is as simple as that:

// the download feature is enabled whenever a specific version is enabled, for example `25_1` or `24_0_1`
#[cfg(feature = "download")]
{
  let bitcoind = bitcoind::BitcoinD::from_downloaded().unwrap();
  assert_eq!(0, bitcoind.client.get_blockchain_info().unwrap().blocks);
}

The build script will automatically download the bitcoin core version 25.1 from bitcoin core, verify the binary hash and place it in the build directory for this crate.

When you don't use the auto-download feature you have the following options:

• have bitcoind executable in the PATH
• provide the bitcoind executable via the BITCOIND_EXE env var

if let Ok(exe_path) = bitcoind::exe_path() {
  let bitcoind = bitcoind::BitcoinD::new(exe_path).unwrap();
  assert_eq!(0, bitcoind.client.get_blockchain_info().unwrap().blocks);
}

Startup options could be configured via the [Conf] struct using [BitcoinD::with_conf] or [BitcoinD::from_downloaded_with_conf]

Features

• Waits until bitcoind daemon becomes ready to accept RPC commands
• bitcoind uses a temporary directory as datadir. You can specify the root of your temp directories so that you have the node's datadir in a RAM disk (eg /dev/shm)
• Free ports are requested from the OS. Since you can't reserve the given port, a low probability race condition is still possible, for this reason the process attempts spawning 3 times with different ports.
• The process is killed when the struct goes out of scope no matter how the test finishes.
• Allows easy spawning of dependent processes like:
  • electrs
  • cln
  • elements

Thanks to these features every #[test] could easily run isolated with its own environment.

Doc

To build docs:

RUSTDOCFLAGS="--cfg docsrs" cargo +nightly doc --features download,doc --open

MSRV

The MSRV is 1.56.1 for version 0.35.*

Note: to respect 1.56.1 MSRV you need to use and older version of some dependencies, in CI the below dependency versions are pinned:

cargo update
cargo update -p tempfile --precise 3.3.0
cargo update -p log --precise 0.4.18

Pinning in Cargo.toml is avoided because it could cause compilation issues downstream.

Nix

For reproducibility reasons, Nix build scripts cannot hit the internet, but the auto-download feature does exactly that. To successfully build under Nix the user must provide the tarball locally and specify its location via the BITCOIND_TARBALL_FILE env var.

Another option is to specify the BITCOIND_SKIP_DOWNLOAD env var and provide the executable via the PATH.

Alternatively, use the dep without the auto-download feature.