Tool for synchronizing keepass repositories over SSH

keepass-ssh-sync.rs

#!/usr/bin/env -S cargo +nightly -Z script
---
edition = "2024"
[dependencies]
tempfile = "3"
thiserror = "1"
reflink-copy = "0.1"
chrono = "0.4"
---

#![feature(bool_to_result)]

use reflink_copy::reflink_or_copy;
use std::io;
use std::os::unix::fs::PermissionsExt;
use std::path::PathBuf;
use std::process::Command;
use thiserror::Error;

#[derive(Error, Debug)]
enum Error {
    #[error("missing local kdbx path")]
    MissingLocalDbPath,

    #[error("missing remote ssh path")]
    MissingRemoteSshPath,

    #[error("failed to download remote database")]
    ScpDownloadFailed,

    #[error("failed to upload merged database")]
    ScpUploadFailed,

    #[error("local merge failed (local database is not updated)")]
    MergeFailed,

    #[error("{0}")]
    Io(#[from] io::Error),
}

macro_rules! oscat {
    ($($part:expr),+ $(,)?) => {{
        let capacity = 0 $(+ AsRef::<std::ffi::OsStr>::as_ref(&$part).len())+;
        let mut result = std::ffi::OsString::with_capacity(capacity);
        $(result.push($part);)+
        result
    }};
}

fn main() {
    if let Err(e) = run() {
        eprintln!("Error: {}", e);
        std::process::exit(1);
    }
}

fn run() -> Result<(), Error> {
    let mut args = std::env::args_os().skip(1);
    let local_db = PathBuf::from(args.next().ok_or(Error::MissingLocalDbPath)?);
    let ssh_path = args.next().ok_or(Error::MissingRemoteSshPath)?;

    let timestamp = chrono::Local::now().format("%Y-%m-%dT%H:%M:%S").to_string();

    reflink_or_copy(&local_db, oscat![&local_db, ".backup.", &timestamp])?;

    let temp_dir = tempfile::Builder::new()
        .permissions(std::fs::Permissions::from_mode(0o700))
        .tempdir()?;
    let temp_remote = temp_dir.path().join("remote.kdbx");

    Command::new("scp")
        .arg(&ssh_path)
        .arg(&temp_remote)
        .status()?
        .success()
        .ok_or(Error::ScpDownloadFailed)?;

    Command::new("keepassxc-cli")
        .args(&["merge", "--same-credentials"])
        .arg(&local_db)
        .arg(&temp_remote)
        .status()?
        .success()
        .ok_or(Error::MergeFailed)?;

    Command::new("rsync")
        .args(&["-avc", "--backup", "--backup-dir=."])
        .arg("--suffix")
        .arg(format!(".backup.{}", &timestamp))
        .arg(&local_db)
        .arg(&ssh_path)
        .status()?
        .success()
        .ok_or(Error::ScpUploadFailed)?;

    Ok(())
}