zoi_package/

bwrap.rs

//! Linux isolation using Bubblewrap.
//!
//! This module provides a way to run Zoi package builds inside a
//! Bubblewrap (`bwrap`) sandbox on Linux. This ensures that the build
//! process is isolated from the host system and has restricted access
//! to the filesystem and network.

use std::path::Path;

use anyhow::{Result, anyhow};

/// Runs the package build process inside a Bubblewrap sandbox.
///
/// # Errors
///
/// Returns an error if:
/// - Not running on Linux.
/// - Bubblewrap is not installed.
/// - The build process fails inside the sandbox.
pub fn run(
    package_file: &Path,
    build_type: Option<&str>,
    platforms: &[String],
    sign_key: Option<String>,
    output_dir: Option<&Path>,
    version_override: Option<&str>,
    sub_packages: Option<Vec<String>>,
    fakeroot: bool,
    install_deps: bool,
    test: bool
) -> Result<()> {
    #[cfg(not(target_os = "linux"))]
    {
        let _ = (
            package_file,
            build_type,
            platforms,
            sign_key,
            output_dir,
            version_override,
            sub_packages,
            fakeroot,
            install_deps,
            test
        );
        return Err(anyhow!(
            "Bubblewrap ('bwrap') is only supported on Linux."
        ));
    }

    #[cfg(target_os = "linux")]
    {
        use std::path::PathBuf;
        use std::process::Command;

        use colored::Colorize;
        use zoi_core::utils;

        println!(
            "{} Building package using Bubblewrap sandbox...",
            "::".bold().blue()
        );

        if !utils::command_exists("bwrap") {
            return Err(anyhow!(
                "Bubblewrap ('bwrap') is not installed or not in PATH. Please \
                 install it to use this method."
            ));
        }

        let abs_package_file = package_file.canonicalize()?;
        let package_dir = abs_package_file.parent().ok_or_else(|| {
            anyhow!("Could not get parent directory of package file")
        })?;

        let abs_output_dir = if let Some(dir) = output_dir {
            if !dir.exists() {
                std::fs::create_dir_all(dir)?;
            }
            dir.canonicalize()?
        } else {
            package_dir.to_path_buf()
        };

        // We use a temporary directory for the build inside the sandbox
        let container_workdir = "/work";
        let container_output_dir = "/output";

        let zoi_exe = std::env::current_exe()?;
        let zoi_exe_dir = zoi_exe
            .parent()
            .ok_or_else(|| anyhow!("Could not get zoi executable directory"))?;

        let home_dir = zoi_core::utils::get_user_home()
            .ok_or_else(|| anyhow!("Could not get home directory"))?;
        let zoi_data_dir = zoi_core::utils::get_user_data_dir()?;

        let package_filename = abs_package_file
            .file_name()
            .ok_or_else(|| anyhow!("Invalid package file name"))?
            .to_string_lossy()
            .into_owned();
        let build_args = build_command_args(
            package_filename,
            build_type,
            platforms,
            sign_key,
            container_output_dir,
            version_override,
            sub_packages,
            fakeroot,
            install_deps,
            test
        );

        // Base bwrap arguments
        let sysroot = zoi_core::sysroot::get_sysroot();

        let mut envs = std::collections::HashMap::new();
        envs.insert(
            "PATH".to_string(),
            "/zoi_bin:/usr/bin:/bin:/usr/sbin:/sbin".to_string()
        );
        envs.insert("ZOI_SKIP_LOCK".to_string(), "1".to_string());
        envs.insert("HOME".to_string(), home_dir.display().to_string());

        let status = if let Some(root) = &sysroot {
            println!(
                "{} Isolated build using sysroot: {}",
                "::".bold().yellow(),
                root.display()
            );

            let extra_binds = vec![
                (package_dir.to_path_buf(), PathBuf::from(container_workdir)),
                (abs_output_dir.clone(), PathBuf::from(container_output_dir)),
                (zoi_exe_dir.to_path_buf(), PathBuf::from("/zoi_bin")),
            ];

            let mut cmd = zoi_sandbox::wrap_command_in_root(
                root,
                &PathBuf::from("/zoi_bin/zoi"),
                &build_args,
                &envs,
                &extra_binds,
                fakeroot
            )?;
            cmd.status()?
        } else {
            // Base bwrap arguments for non-sysroot build
            let mut bwrap_args = vec![
                "--unshare-all".to_string(),
                "--share-net".to_string(),
                "--hostname".to_string(),
                "zoi-build".to_string(),
                "--dev".to_string(),
                "/dev".to_string(),
                "--proc".to_string(),
                "/proc".to_string(),
                "--tmpfs".to_string(),
                "/tmp".to_string(),
                "--tmpfs".to_string(),
                "/run".to_string(),
                "--tmpfs".to_string(),
                "/var".to_string(),
                "--ro-bind".to_string(),
                "/usr".to_string(),
                "/usr".to_string(),
                "--symlink".to_string(),
                "/usr/bin".to_string(),
                "/bin".to_string(),
                "--symlink".to_string(),
                "/usr/lib".to_string(),
                "/lib".to_string(),
                "--symlink".to_string(),
                "/usr/lib64".to_string(),
                "/lib64".to_string(),
                "--symlink".to_string(),
                "/usr/sbin".to_string(),
                "/sbin".to_string(),
                "--ro-bind".to_string(),
                "/etc".to_string(),
                "/etc".to_string(),
                "--bind".to_string(),
                package_dir.display().to_string(),
                container_workdir.to_string(),
                "--bind".to_string(),
                abs_output_dir.display().to_string(),
                container_output_dir.to_string(),
                "--ro-bind".to_string(),
                zoi_exe_dir.display().to_string(),
                "/zoi_bin".to_string(),
                "--chdir".to_string(),
                container_workdir.to_string(),
                "--setenv".to_string(),
                "PATH".to_string(),
                "/zoi_bin:/usr/bin:/bin:/usr/sbin:/sbin".to_string(),
                "--setenv".to_string(),
                "ZOI_SKIP_LOCK".to_string(),
                "1".to_string(),
            ];

            if zoi_data_dir.exists() {
                bwrap_args.push("--bind".to_string());
                bwrap_args.push(zoi_data_dir.display().to_string());
                bwrap_args.push(zoi_data_dir.display().to_string());
            }

            let system_zoi = Path::new("/var/lib/zoi");
            if system_zoi.exists() {
                bwrap_args.push("--bind".to_string());
                bwrap_args.push(system_zoi.display().to_string());
                bwrap_args.push(system_zoi.display().to_string());
            }

            if fakeroot {
                bwrap_args.push("--uid".to_string());
                bwrap_args.push("0".to_string());
                bwrap_args.push("--gid".to_string());
                bwrap_args.push("0".to_string());
            } else {
                let uid = nix::unistd::getuid().as_raw();
                let gid = nix::unistd::getgid().as_raw();
                bwrap_args.push("--uid".to_string());
                bwrap_args.push(uid.to_string());
                bwrap_args.push("--gid".to_string());
                bwrap_args.push(gid.to_string());
            }

            bwrap_args.push("--setenv".to_string());
            bwrap_args.push("HOME".to_string());
            bwrap_args.push(home_dir.display().to_string());

            bwrap_args.push("/zoi_bin/zoi".to_string());
            bwrap_args.extend(build_args);

            Command::new("bwrap").args(&bwrap_args).status()?
        };

        if !status.success() {
            return Err(anyhow!(
                "Bubblewrap build failed with exit code {:?}",
                status.code()
            ));
        }

        println!("{}", "Bubblewrap build successful!".green());

        Ok(())
    }
}

#[allow(clippy::too_many_arguments)]
/// Builds the argument vector passed directly to `zoi` inside Bubblewrap.
fn build_command_args(
    package_filename: String,
    build_type: Option<&str>,
    platforms: &[String],
    sign_key: Option<String>,
    output_dir: &str,
    version_override: Option<&str>,
    sub_packages: Option<Vec<String>>,
    fakeroot: bool,
    install_deps: bool,
    test: bool
) -> Vec<String> {
    let mut args = vec![
        "package".to_string(),
        "build".to_string(),
        package_filename,
        "--output-dir".to_string(),
        output_dir.to_string(),
        "--method".to_string(),
        "native".to_string(),
    ];

    if let Some(build_type) = build_type {
        args.extend(["--type".to_string(), build_type.to_string()]);
    }
    for platform in platforms {
        args.extend(["--platform".to_string(), platform.clone()]);
    }
    if let Some(sign_key) = sign_key {
        args.extend(["--sign".to_string(), sign_key]);
    }
    if let Some(version_override) = version_override {
        args.extend([
            "--version-override".to_string(),
            version_override.to_string()
        ]);
    }
    if let Some(sub_packages) = sub_packages {
        for sub_package in sub_packages {
            args.extend(["--sub".to_string(), sub_package]);
        }
    }
    if fakeroot {
        args.push("--fakeroot".to_string());
    }
    if install_deps {
        args.push("--install-deps".to_string());
    }
    if test {
        args.push("--test".to_string());
    }

    args
}

#[cfg(test)]
mod tests {
    use super::build_command_args;

    #[test]
    fn build_arguments_keep_shell_syntax_as_data() {
        let args = build_command_args(
            "package; touch /tmp/pwned.pkg.lua".to_string(),
            Some("source; id"),
            &["linux-amd64; id".to_string()],
            Some("key; id".to_string()),
            "/output",
            Some("1.0.0; id"),
            Some(vec!["sub; id".to_string()]),
            true,
            true,
            true
        );

        assert!(
            args.contains(&"package; touch /tmp/pwned.pkg.lua".to_string())
        );
        assert!(args.contains(&"source; id".to_string()));
        assert!(args.contains(&"linux-amd64; id".to_string()));
        assert!(args.contains(&"key; id".to_string()));
        assert!(args.contains(&"1.0.0; id".to_string()));
        assert!(args.contains(&"sub; id".to_string()));
    }
}