monitor/src/utils.rs

use std::sync::Arc;
use crate::structs::TrackingProcess;
use tokio::sync::mpsc;
use inotify::Inotify;
use std::process::Command;
use crate::files::create_watcher;
use log::{error, warn};
use crate::prcs::{
    is_active, 
    is_frozen,
    terminate_process, 
    restart_process, 
    freeze_process, 
    unfreeze_process,
    start_process
};
use tokio::time::Duration;
use tokio::join;
use crate::files::file_handler;
use crate::services::service_handler;

static GET_ID_CMD : &'static str = r"cat /proc/self/mountinfo | grep '/docker/containers/' | head -1 | awk -F '/' '{print \$6}'";

/// # async func to run 3 main daemons (now it's more like tree-form than classical 0.1.0 form )
/// > hint : give mpsc with capacity 1 to jump over potential errors during running process
/// ** in [developing](https://github.com/prplV/runner-rs "REPOSITORY") **
pub async fn run_daemons(
    proc: Arc<TrackingProcess>, 
    tx: Arc<mpsc::Sender<u8>>,
    rx: &mut mpsc::Receiver<u8>
) 
{
    // creating watchers + ---buffers---
    let mut watchers: Vec<Inotify> = vec![];
    for file in proc.dependencies.files.clone().into_iter() {
        watchers.push(create_watcher(&file.filename, &file.src).await.unwrap());
    }
    let watchers_clone: Arc<tokio::sync::Mutex<Vec<Inotify>>> = Arc::new(tokio::sync::Mutex::new(watchers));

    loop {
        let run_hand = running_handler(proc.clone(), tx.clone(), watchers_clone.clone());
        tokio::select! {
            _ = run_hand => {},
            _val = rx.recv() => {
                match _val.unwrap() {
                    // 1 - File-dependency handling error -> terminating (after waiting)
                    1 => {
                        if is_active(&proc.name).await {
                            error!("Dependency handling error: Terminating {} process ..." , &proc.name);
                            terminate_process(&proc.name).await;
                            tokio::time::sleep(Duration::from_millis(100)).await;
                        }
                        // break;
                    },
                    // 2 - File-dependency handling error -> holding (after waiting)
                    2 => {
                        if !is_frozen(&proc.name).await {
                            error!("Dependency handling error: Freezing {} process ..." , &proc.name);
                            freeze_process(&proc.name).await;
                            tokio::time::sleep(Duration::from_millis(100)).await;
                        }
                    },
                    // 3 - Running process error
                    3 => {
                        error!("Error due to starting {} process", &proc.name);
                    },
                    // 4 - Timeout of waiting service-dependency -> staying (after waiting) 
                    4 => {
                        warn!("Timeout of waiting service-dependency: Ignoring  on {} process ..." , &proc.name);
                    },
                    // 5 - Timeout of waiting service-dependency -> terminating (after waiting)
                    5 => {
                        if is_active(&proc.name).await {
                            error!("Timeout of waiting service-dependency: Terminating {} process ..." , &proc.name);
                            terminate_process(&proc.name).await;
                            tokio::time::sleep(Duration::from_millis(100)).await;
                        }
                        // break;
                    },
                    // 6 - Timeout of waiting service-dependency -> holding (after waiting)
                    6 => {
                        if !is_frozen(&proc.name).await {
                            error!("Timeout of waiting service-dependency: Freezing {} process ..." , &proc.name);
                            freeze_process(&proc.name).await;
                            tokio::time::sleep(Duration::from_millis(100)).await;
                        }
                    },
                    // // 7 - File-dependency change -> terminating (after check)
                    7 => {
                        error!("File-dependency warning (file changed). Terminating {} process...", &proc.name);
                        terminate_process(&proc.name).await;
                        tokio::time::sleep(Duration::from_millis(100)).await;
                    },
                    // // 8 - File-dependency change -> restarting (after check)
                    8 => {
                        warn!("File-dependency warning (file changed). Restarting {} process...", &proc.name);
                        let _ = restart_process(&proc.name, &proc.path).await;
                        tokio::time::sleep(Duration::from_millis(100)).await;
                    },
                    // // 9 - File-dependency change -> staying (after check)
                    9 => {
                        warn!("File-dependency warning (file changed). Ignoring on {} process...", &proc.name);
                    },

                    // 10 - Process unfreaze call via file handler
                    10 => {
                        if is_frozen(&proc.name).await {
                            warn!("Unfreezing process {} call...", &proc.name);
                            unfreeze_process(&proc.name).await;
                        }
                    },
                    // 11 - Process unfreaze call via service handler
                    11 => {
                        if is_frozen(&proc.name).await {
                            warn!("Unfreezing process {} call...", &proc.name);
                            unfreeze_process(&proc.name).await;
                        }
                    },
                    // 101 - Impermissible trigger values in JSON
                    101 => {
                        error!("Impermissible trigger values in JSON");
                        if is_active(&proc.name).await {
                            terminate_process(&proc.name).await;
                        }
                        break;
                    },
                    _ => {}, 
                }
            },
        }
        // tokio::task::yield_now().await;
    }    
}
// check process status daemon 
pub async fn running_handler
(
    prc: Arc<TrackingProcess>, 
    tx: Arc<mpsc::Sender<u8>>, 
    watchers: Arc<tokio::sync::Mutex<Vec<Inotify>>>
)
{
    // println!("running daemon on {}", prc.name);
    // services and files check (once)  
    let files_check = file_handler(&prc.name, &prc.dependencies.files, tx.clone(), watchers.clone());
    let services_check = service_handler(&prc.name, &prc.dependencies.services, tx.clone());

    let res = join!(files_check, services_check);
    // if inactive -> spawn checks -> active is true 
    if !is_active(&prc.name).await && res.0.is_ok() && res.1.is_ok(){
        if start_process(&prc.name, &prc.path).await.is_err() {
            tx.send(3).await.unwrap();
            return;
        }
    } 
    // if frozen  -> spawn checks -> unfreeze is true
    else if is_frozen(&prc.name).await && res.0.is_ok() && res.1.is_ok(){
        tx.send(10).await.unwrap();
        return;
    }
    tokio::time::sleep(Duration::from_millis(100)).await;
    tokio::task::yield_now().await;
}


// todo: cmd across cat /proc/self/mountinfo | grep "/docker/containers/" | head -1 | awk -F '/' '{print $5}'
pub fn get_container_id() -> Option<String> {
    match Command::new("sh -c").arg(GET_ID_CMD).output() {
        Ok(output) => {
            Some(String::from_utf8_lossy(&output.stdout).to_string())
        },
        Err(_) => {
            None     
        },
    }
}