electrs/src/config.rs

use bitcoin::network::constants::Network;
use bitcoincore_rpc::Auth;
use dirs_next::home_dir;

use std::ffi::{OsStr, OsString};
use std::fmt;
use std::net::SocketAddr;
use std::net::ToSocketAddrs;
use std::path::PathBuf;
use std::str::FromStr;

use std::time::Duration;

const DEFAULT_SERVER_ADDRESS: [u8; 4] = [127, 0, 0, 1]; // by default, serve on IPv4 localhost

mod internal {
    #![allow(unused)]

    include!(concat!(env!("OUT_DIR"), "/configure_me_config.rs"));
}

/// A simple error type representing invalid UTF-8 input.
pub struct InvalidUtf8(OsString);

impl fmt::Display for InvalidUtf8 {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        write!(f, "{:?} isn't a valid UTF-8 sequence", self.0)
    }
}

/// An error that might happen when resolving an address
pub enum AddressError {
    ResolvError { addr: String, err: std::io::Error },
    NoAddrError(String),
}

impl fmt::Display for AddressError {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            AddressError::ResolvError { addr, err } => {
                write!(f, "Failed to resolve address {}: {}", addr, err)
            }
            AddressError::NoAddrError(addr) => write!(f, "No address found for {}", addr),
        }
    }
}

/// Newtype for an address that is parsed as `String`
///
/// The main point of this newtype is to provide better description than what `String` type
/// provides.
#[derive(Deserialize)]
pub struct ResolvAddr(String);

impl ::configure_me::parse_arg::ParseArg for ResolvAddr {
    type Error = InvalidUtf8;

    fn parse_arg(arg: &OsStr) -> std::result::Result<Self, Self::Error> {
        Self::parse_owned_arg(arg.to_owned())
    }

    fn parse_owned_arg(arg: OsString) -> std::result::Result<Self, Self::Error> {
        arg.into_string().map_err(InvalidUtf8).map(ResolvAddr)
    }

    fn describe_type<W: fmt::Write>(mut writer: W) -> fmt::Result {
        write!(writer, "a network address (will be resolved if needed)")
    }
}

impl ResolvAddr {
    /// Resolves the address.
    fn resolve(self) -> std::result::Result<SocketAddr, AddressError> {
        match self.0.to_socket_addrs() {
            Ok(mut iter) => iter.next().ok_or(AddressError::NoAddrError(self.0)),
            Err(err) => Err(AddressError::ResolvError { addr: self.0, err }),
        }
    }

    /// Resolves the address, but prints error and exits in case of failure.
    fn resolve_or_exit(self) -> SocketAddr {
        self.resolve().unwrap_or_else(|err| {
            eprintln!("Error: {}", err);
            std::process::exit(1)
        })
    }
}

/// This newtype implements `ParseArg` for `Network`.
#[derive(Deserialize)]
pub struct BitcoinNetwork(Network);

impl Default for BitcoinNetwork {
    fn default() -> Self {
        BitcoinNetwork(Network::Bitcoin)
    }
}

impl FromStr for BitcoinNetwork {
    type Err = <Network as FromStr>::Err;

    fn from_str(string: &str) -> std::result::Result<Self, Self::Err> {
        Network::from_str(string).map(BitcoinNetwork)
    }
}

impl ::configure_me::parse_arg::ParseArgFromStr for BitcoinNetwork {
    fn describe_type<W: fmt::Write>(mut writer: W) -> fmt::Result {
        write!(writer, "either 'bitcoin', 'testnet', 'regtest' or 'signet'")
    }
}

impl From<BitcoinNetwork> for Network {
    fn from(network: BitcoinNetwork) -> Network {
        network.0
    }
}

/// Parsed and post-processed configuration
#[derive(Debug)]
pub struct Config {
    // See below for the documentation of each field:
    pub network: Network,
    pub db_path: PathBuf,
    pub daemon_dir: PathBuf,
    pub daemon_auth: SensitiveAuth,
    pub daemon_rpc_addr: SocketAddr,
    pub daemon_p2p_addr: SocketAddr,
    pub electrum_rpc_addr: SocketAddr,
    pub monitoring_addr: SocketAddr,
    pub wait_duration: Duration,
    pub index_batch_size: usize,
    pub ignore_mempool: bool,
    pub server_banner: String,
    pub args: Vec<String>,
}

pub struct SensitiveAuth(pub Auth);

impl SensitiveAuth {
    pub(crate) fn get_auth(&self) -> Auth {
        self.0.clone()
    }
}

impl fmt::Debug for SensitiveAuth {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self.0 {
            Auth::UserPass(ref user, _) => f
                .debug_tuple("UserPass")
                .field(&user)
                .field(&"<sensitive>")
                .finish(),
            _ => write!(f, "{:?}", self.0),
        }
    }
}

/// Returns default daemon directory
fn default_daemon_dir() -> PathBuf {
    let mut home = home_dir().unwrap_or_else(|| {
        eprintln!("Error: unknown home directory");
        std::process::exit(1)
    });
    home.push(".bitcoin");
    home
}

impl Config {
    /// Parses args, env vars, config files and post-processes them
    pub fn from_args() -> Config {
        use internal::ResultExt;

        let system_config: &OsStr = "/etc/electrs/config.toml".as_ref();
        let home_config = home_dir().map(|mut dir| {
            dir.extend(&[".electrs", "config.toml"]);
            dir
        });
        let cwd_config: &OsStr = "electrs.toml".as_ref();
        let configs = std::iter::once(cwd_config)
            .chain(home_config.as_ref().map(AsRef::as_ref))
            .chain(std::iter::once(system_config));

        let (mut config, args) =
            internal::Config::including_optional_config_files(configs).unwrap_or_exit();

        let db_subdir = match config.network {
            Network::Bitcoin => "bitcoin",
            Network::Testnet => "testnet",
            Network::Regtest => "regtest",
            Network::Signet => "signet",
        };

        config.db_dir.push(db_subdir);

        let default_daemon_rpc_port = match config.network {
            Network::Bitcoin => 8332,
            Network::Testnet => 18332,
            Network::Regtest => 18443,
            Network::Signet => 38332,
        };
        let default_daemon_p2p_port = match config.network {
            Network::Bitcoin => 8333,
            Network::Testnet => 18333,
            Network::Regtest => 18444,
            Network::Signet => 38333,
        };
        let default_electrum_port = match config.network {
            Network::Bitcoin => 50001,
            Network::Testnet => 60001,
            Network::Regtest => 60401,
            Network::Signet => 60601,
        };
        let default_monitoring_port = match config.network {
            Network::Bitcoin => 4224,
            Network::Testnet => 14224,
            Network::Regtest => 24224,
            Network::Signet => 34224,
        };

        let daemon_rpc_addr: SocketAddr = config.daemon_rpc_addr.map_or(
            (DEFAULT_SERVER_ADDRESS, default_daemon_rpc_port).into(),
            ResolvAddr::resolve_or_exit,
        );
        let daemon_p2p_addr: SocketAddr = config.daemon_p2p_addr.map_or(
            (DEFAULT_SERVER_ADDRESS, default_daemon_p2p_port).into(),
            ResolvAddr::resolve_or_exit,
        );
        let electrum_rpc_addr: SocketAddr = config.electrum_rpc_addr.map_or(
            (DEFAULT_SERVER_ADDRESS, default_electrum_port).into(),
            ResolvAddr::resolve_or_exit,
        );
        #[cfg(not(feature = "metrics"))]
        {
            if config.monitoring_addr.is_some() {
                eprintln!("Error: enable \"metrics\" feature to specify monitoring_addr");
                std::process::exit(1);
            }
        }
        let monitoring_addr: SocketAddr = config.monitoring_addr.map_or(
            (DEFAULT_SERVER_ADDRESS, default_monitoring_port).into(),
            ResolvAddr::resolve_or_exit,
        );

        match config.network {
            Network::Bitcoin => (),
            Network::Testnet => config.daemon_dir.push("testnet3"),
            Network::Regtest => config.daemon_dir.push("regtest"),
            Network::Signet => config.daemon_dir.push("signet"),
        }

        let daemon_dir = &config.daemon_dir;
        let daemon_auth = SensitiveAuth(match (config.auth, config.cookie_file) {
            (None, None) => Auth::CookieFile(daemon_dir.join(".cookie")),
            (None, Some(cookie_file)) => Auth::CookieFile(cookie_file),
            (Some(auth), None) => {
                let parts: Vec<&str> = auth.splitn(2, ":").collect();
                if parts.len() != 2 {
                    eprintln!("Error: auth cookie doesn't contain colon");
                    std::process::exit(1);
                }
                Auth::UserPass(parts[0].to_owned(), parts[1].to_owned())
            }
            (Some(_), Some(_)) => {
                eprintln!("Error: ambigous configuration - auth and cookie_file can't be specified at the same time");
                std::process::exit(1);
            }
        });

        let level = match config.verbose {
            0 => log::LevelFilter::Info,
            1 => log::LevelFilter::Debug,
            _ => log::LevelFilter::Trace,
        };

        let config = Config {
            network: config.network,
            db_path: config.db_dir,
            daemon_dir: config.daemon_dir,
            daemon_auth,
            daemon_rpc_addr,
            daemon_p2p_addr,
            electrum_rpc_addr,
            monitoring_addr,
            wait_duration: Duration::from_secs(config.wait_duration_secs),
            index_batch_size: config.index_batch_size,
            ignore_mempool: config.ignore_mempool,
            server_banner: config.server_banner,
            args: args.map(|a| a.into_string().unwrap()).collect(),
        };
        eprintln!("{:?}", config);
        env_logger::Builder::from_default_env()
            .default_format()
            .format_timestamp_millis()
            .filter_level(level)
            .init();
        config
    }
}

#[cfg(test)]
mod tests {
    use super::{Auth, SensitiveAuth};
    use std::path::Path;

    #[test]
    fn test_auth_debug() {
        let auth = Auth::None;
        assert_eq!(format!("{:?}", SensitiveAuth(auth)), "None");

        let auth = Auth::CookieFile(Path::new("/foo/bar/.cookie").to_path_buf());
        assert_eq!(
            format!("{:?}", SensitiveAuth(auth)),
            "CookieFile(\"/foo/bar/.cookie\")"
        );

        let auth = Auth::UserPass("user".to_owned(), "pass".to_owned());
        assert_eq!(
            format!("{:?}", SensitiveAuth(auth)),
            "UserPass(\"user\", \"<sensitive>\")"
        );
    }
}