Crate bitcoind

source ·
Expand description

MIT license Crates Docs

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 23_0 for bitcoin core 23.0, starting a regtest node is as simple as that:

// the download feature is enabled whenever a specific version is enabled, for example `23_0` or `22_0`
#[cfg(feature = "download")]
{
  use bitcoincore_rpc::RpcApi;
  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 23.0 from bitcoin core, verify the hashes and place it in the build directory for this crate. If you wish to download from an alternate location, for example locally for CI, use the BITCOIND_DOWNLOAD_ENDPOINT env var.

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_EXEC env var
use bitcoincore_rpc::RpcApi;
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

Issues with traditional approach

I used integration testing based on external bash script launching needed external processes, there are many issues with this approach like:

  • External script may interfere with local development environment 1
  • Use of a single huge test to test everything 2
  • If test are separated, a failing test may fail to leave a clean situation, causing other test to fail (because of the initial situation, not a real failure)
  • bash script are hard, especially support different OS and versions

Features

  • It waits until bitcoind daemon become ready to accept RPC commands
  • bitcoind use a temporary directory as datadir. You can specify the root of your temp directories so that you have node’s datadir in a RAM disk (eg /dev/shm)
  • Free ports are asked to the OS. Since you can’t reserve the given portm a low probability race condition is still possible, for this reason the process is tried to be spawn 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 process like electrs

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 1.41.1 for version 0.29.* if no feature is used, otherwise is 1.57

Note: to respect 1.41.1 MSRV you need to use and older version of the which and tempfile dependencies, like it’s done in the CI:

cargo update -p which --precise 4.3.0
cargo update -p serde --precise 1.0.152
cargo update -p tempfile --precise 3.3.0

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

Used by

Via bdk dependency

Via electrsd dependency:

Re-exports

Structs

  • BitcoinD
    Struct representing the bitcoind process with related information
  • Conf
    The node configuration parameters, implements a convenient Default for most common use.
  • ConnectParams
    Contains all the information to connect to this node

Enums

  • DataDir
    The DataDir struct defining the kind of data directory the node will contain. Data directory can be either persistent, or temporary.
  • Error
    All the possible error in this crate
  • P2P
    Enum to specify p2p settings

Functions

  • downloaded_exe_path
    Provide the bitcoind executable path if a version feature has been specified
  • exe_path
    Returns the daemon executable path if it’s provided as a feature or as BITCOIND_EXE env var. Returns error if none or both are set
  • get_available_port
    Returns a non-used local port if available.
  • validate_args
    Validate the specified arg if there is any unavailable or deprecated one