rustcracker 1.1.1+deprecated

use crate::config::HypervisorConfig;
use crate::{handle_entry, handle_entry_default, handle_entry_ref};
use crate::{RtckError, RtckResult};
use log::*;
use serde::{Deserialize, Serialize};
use std::{os::unix::net::UnixStream, path::PathBuf};

#[derive(Debug, Clone, Serialize, Deserialize)]
pub(crate) struct JailerSync {
    // Path to local jailer bin
    // Usually something like `/usr/bin/jailer`
    bin: String,

    // Id of this jailer
    pub(crate) id: String,

    // Path to local firecracker bin
    exec_file: String,

    // Uid
    uid: u32,

    // Gid
    gid: u32,

    // chroot base directory, default to /srv/jailer
    chroot_base_dir: String,

    // Daemonize or not
    daemonize: bool,

    // Jailer workspace directory
    jailer_workspace_dir: Option<PathBuf>,

    // Desired path of the socket
    socket: Option<String>,

    // Socket path seen by Rtck
    socket_path_export: Option<PathBuf>,

    // Desired path of the lock
    lock_path: Option<String>,

    // Lock path seen by Rtck
    lock_path_export: Option<PathBuf>,

    // Path to the config file
    config_path: Option<String>,

    // Config file path seen by firecracker
    config_path_jailed: Option<PathBuf>,

    // Log path seen by firecracker
    log_path: Option<String>,

    // Log path seen by Rtck
    log_path_export: Option<PathBuf>,

    // Metrics path seen by firecracker
    metrics_path: Option<String>,

    // Metrics path seen by Rtck
    metrics_path_export: Option<PathBuf>,
}

impl JailerSync {
    pub(crate) fn get_uid(&self) -> u32 {
        self.uid
    }

    pub(crate) fn get_gid(&self) -> u32 {
        self.gid
    }

    pub(crate) fn get_firecracker_exec_file(&self) -> &String {
        &self.exec_file
    }

    pub(crate) fn get_socket_path_exported(&self) -> Option<&PathBuf> {
        self.socket_path_export.as_ref()
    }

    // pub(crate) fn get_lock_path_exported(&self) -> Option<&PathBuf> {
    //     self.lock_path_export.as_ref()
    // }

    pub(crate) fn get_log_path_exported(&self) -> Option<&PathBuf> {
        self.log_path_export.as_ref()
    }

    #[allow(unused)]
    pub(crate) fn get_metrics_path_exported(&self) -> Option<&PathBuf> {
        self.metrics_path_export.as_ref()
    }

    pub(crate) fn get_config_path_exported(&self) -> Option<&String> {
        self.config_path.as_ref()
    }

    pub(crate) fn get_jailer_workspace_dir(&self) -> Option<&PathBuf> {
        self.jailer_workspace_dir.as_ref()
    }
}

impl JailerSync {
    pub(crate) fn from_config(config: &HypervisorConfig) -> RtckResult<Self> {
        config.validate()?;

        let jailer_config = config.jailer_config.as_ref().ok_or_else(|| {
            let msg = "Missing jailer config";
            error!("{msg}");
            RtckError::Config(msg.into())
        })?;

        let id = if let Some(id) = &config.id {
            id.clone()
        } else {
            uuid::Uuid::new_v4().to_string()
        };

        let socket = if let Some(socket) = &config.socket_path {
            socket.clone()
        } else {
            // allocate one. format: run/firecracker.socket
            "run/firecracker.socket".to_string()
        };
        let socket = Some(socket);

        const DEFAULT_CHROOT_BASE_DIR: &'static str = "/srv/jailer";
        Ok(Self {
            bin: handle_entry(&jailer_config.jailer_bin, "jailer binary")?,
            id,
            exec_file: handle_entry(&jailer_config.exec_file, "firecracker executable file")?,
            uid: handle_entry(&jailer_config.uid, "jailer uid")?,
            gid: handle_entry(&jailer_config.gid, "jailer gid")?,
            chroot_base_dir: handle_entry_default(
                &jailer_config.chroot_base_dir,
                DEFAULT_CHROOT_BASE_DIR.into(),
            ),
            daemonize: jailer_config.daemonize.unwrap_or(false),
            jailer_workspace_dir: None,
            socket,
            socket_path_export: None,
            lock_path: config.lock_path.clone(),
            lock_path_export: None,
            config_path: config.frck_export_path.clone(),
            config_path_jailed: None,
            log_path: config.log_path.clone(),
            log_path_export: None,
            metrics_path: config.metrics_path.clone(),
            metrics_path_export: None,
        })
    }

    pub(crate) fn jail(&mut self) -> RtckResult<PathBuf> {
        let id = &self.id;
        let temp_binding = PathBuf::from(&self.exec_file);
        let exec_file_name =
            *handle_entry_ref(&temp_binding.file_name(), "firecracker executable file")?;
        let chroot_base_dir = &self.chroot_base_dir;
        const ROOT_FOLDER_NAME: &'static str = "root";
        let instance_dir = PathBuf::from(chroot_base_dir).join(exec_file_name).join(id);
        let jailer_workspace_dir = instance_dir.join(ROOT_FOLDER_NAME);
        if jailer_workspace_dir.exists() {
            let msg = "Conflict instance name, please choose another one";
            error!("{msg}");
            return Err(RtckError::Jailer(msg.into()));
        }
        self.jailer_workspace_dir = Some(jailer_workspace_dir.clone());

        // Get socket path under jailer
        const DEFAULT_SOCKET_PATH_UNDER_JAILER: &'static str = "run/firecracker.socket";
        self.socket_path_export = self.get_x_path_under_jailer(
            &self.socket,
            DEFAULT_SOCKET_PATH_UNDER_JAILER,
            "socket",
            &jailer_workspace_dir,
        )?;

        // Get log path under jailer
        const DEFAULT_LOG_PATH_UNDER_JAILER: &'static str = "run/firecracker.log";
        self.log_path_export = self.get_x_path_under_jailer(
            &self.log_path,
            DEFAULT_LOG_PATH_UNDER_JAILER,
            "log",
            &jailer_workspace_dir,
        )?;

        // Get metrics path under jailer
        const DEFAULT_METRICS_PATH_UNDER_JAILER: &'static str = "run/firecracker.metrics";
        self.metrics_path_export = self.get_x_path_under_jailer(
            &self.metrics_path,
            DEFAULT_METRICS_PATH_UNDER_JAILER,
            "metrics",
            &jailer_workspace_dir,
        )?;

        match &self.config_path {
            // not using config exported config, skipping
            None => (),
            Some(config_path) => {
                // copy the config file into the jailer
                const DEFAULT_CONFIG_PATH_JAILED: &'static str = "run/firecracker-config.json";
                self.config_path_jailed = Some(DEFAULT_CONFIG_PATH_JAILED.into());

                let config_path_export = jailer_workspace_dir.join(DEFAULT_CONFIG_PATH_JAILED);
                std::fs::copy(config_path, config_path_export).map_err(|e| {
                    let msg = format!("Fail to copy config when jailing: {e}");
                    error!("{msg}");
                    RtckError::FilesysIO(msg)
                })?;
            }
        }

        Ok(instance_dir)
    }

    fn get_x_path_under_jailer(
        &self,
        x: &Option<String>,
        default_path_under_jailer: &'static str,
        name: &'static str,
        jailer_workspace_dir: &PathBuf,
    ) -> RtckResult<Option<PathBuf>> {
        let path = handle_entry_default(x, default_path_under_jailer.to_string());
        let path = PathBuf::from(path);
        let path = if path.is_absolute() {
            path.strip_prefix("/").map_err(|e| {
                let msg = format!("Fail to strip prefix of {name} path when jailing: {e}");
                error!("{msg}");
                RtckError::Jailer(msg)
            })?
        } else {
            path.as_path()
        };
        Ok(Some(jailer_workspace_dir.join(path)))
    }

    pub(crate) fn launch(&self) -> RtckResult<std::process::Child> {
        let mut cmd = std::process::Command::new(&self.bin);
        cmd.args(vec!["--id", &self.id]);
        cmd.args(vec!["--uid", &self.uid.to_string()]);
        cmd.args(vec!["--gid", &self.gid.to_string()]);
        cmd.args(vec!["--exec-file", &self.exec_file.to_string()]);
        cmd.args(vec!["--chroot-base-dir", &self.chroot_base_dir]);
        if self.daemonize {
            cmd.arg("--daemonize");
        }
        cmd.arg("--");

        match &self.socket {
            None => (),
            Some(path) => {
                cmd.args(vec!["--api-sock", path]);
            }
        }

        match &self.config_path {
            None => (),
            Some(path) => {
                cmd.args(vec!["--config-file", path]);
            }
        }

        cmd.spawn().map_err(|e| {
            let msg = format!("Fail to spawn jailer: {e}");
            error!("{msg}");
            RtckError::Jailer(msg)
        })
    }

    /// Waiting for the socket set by firecracker
    pub(crate) fn waiting_socket(&self, timeout: std::time::Duration) -> RtckResult<()> {
        let start = std::time::Instant::now();
        let socket_path = handle_entry(&self.socket_path_export, "exported socket path")?;
        while start.elapsed() < timeout {
            if socket_path.exists() {
                return Ok(());
            }
            std::thread::sleep(std::time::Duration::from_millis(100)); // check every 100 ms
        }

        Err(RtckError::Jailer("Remote socket timeout".to_string()))
    }

    /// Connect to the socket
    pub(crate) fn connect(&self, retry: usize) -> RtckResult<UnixStream> {
        let mut trying = retry;
        let socket = handle_entry_ref(&self.socket_path_export, "exported socket path")?;
        let stream = loop {
            if trying == 0 {
                return Err(RtckError::Firecracker(format!(
                    "Fail to connect unix socket after {retry} tries"
                )));
            }
            match UnixStream::connect(socket) {
                Ok(stream) => break stream,
                Err(_) => {
                    trying -= 1;
                    std::thread::sleep(std::time::Duration::from_secs(1));
                    continue;
                }
            }
        };
        Ok(stream)
    }
}