feat(schedule): add support to scheduled tasks with --cron

Cargo.toml

@@ -23,3 +23,4 @@ json = "^0.12"
 hostname = "^0.3"
 regex = "^1.3"
 chrono = "^0.4"
+cron = "0.12"

src/commands/exec.rs

@@ -1,5 +1,7 @@
 use crate::config::Config;
-use crate::utils::traits::CommandConfig;
+use crate::utils::traits::{CommandConfig, WaitSchedule};
+use chrono::Local;
+use cron::Schedule;
 use libc::{fork, signal};
 use libc::{SIGHUP, SIG_IGN};
 use std::fs;
@@ -9,7 +11,9 @@ use structopt::StructOpt;
 
 #[derive(Debug, StructOpt)]
 pub struct Exec {
-  /// Configuration path (YAML)
+  /// Configuration path (YAML).
+  /// Will use config file located `~/.runtasktic.yml` or `~/.runtasktic.yaml` by default.
+  /// If you want no config file execusion, use `--config -`
   #[structopt(long = "config", short = "c")]
   config: Option<PathBuf>,
   /// Run a single task from the configuration file.
@@ -18,6 +22,9 @@ pub struct Exec {
   /// Exec the command in background
   #[structopt(long = "background", short = "b")]
   background: bool,
+  /// Schedule your tasks using cron expression.
+  #[structopt(long = "cron")]
+  cron: Option<Schedule>,
   /// Command to execute
   #[structopt()]
   command: Vec<String>,
@@ -31,6 +38,7 @@ impl Exec {
         return;
       }
     }
+    let timezone = Local::now().timezone();
 
     if self.command.is_empty() && self.task.is_none() {
       let clap = crate::Runtasktic::clap();
@@ -46,9 +54,19 @@ impl Exec {
       unsafe { signal(SIGHUP, SIG_IGN) };
     }
 
-    if let Err(e) = self.run() {
-      eprintln!("{}", e);
-      exit(1);
+    loop {
+      self.cron.wait(timezone);
+
+      if let Err(e) = self.run() {
+        eprintln!("{}", e);
+        if self.cron.is_none() {
+          exit(1);
+        }
+      }
+
+      if self.cron.is_none() {
+        break;
+      }
     }
   }
 

src/commands/run.rs

@@ -1,6 +1,8 @@
 use crate::config::{Config, OnFailure};
 use crate::fst::*;
-use crate::utils::traits::CommandConfig;
+use crate::utils::traits::{CommandConfig, WaitSchedule};
+use chrono::Local;
+use cron::Schedule;
 use libc::{fork, signal};
 use libc::{SIGHUP, SIG_IGN};
 use std::fs;
@@ -21,6 +23,9 @@ pub struct Run {
   /// Run the task in background
   #[structopt(long = "background", short = "b")]
   background: bool,
+  /// Schedule your tasks using cron expression.
+  #[structopt(long = "cron")]
+  cron: Option<Schedule>,
 }
 
 impl Run {
@@ -31,6 +36,7 @@ impl Run {
         exit(1);
       }
     }
+    let timezone = Local::now().timezone();
 
     if self.config.is_empty() {
       let clap = crate::Runtasktic::clap();
@@ -46,11 +52,18 @@ impl Run {
       unsafe { signal(SIGHUP, SIG_IGN) };
     }
 
-    for (i, config) in self.config.iter().enumerate() {
-      let starts = if i == 0 { self.starts.clone() } else { vec![] };
-      if let Err(e) = self.run(&config.as_path(), &starts) {
-        eprintln!("{}", e);
-        exit(1);
+    loop {
+      self.cron.wait(timezone);
+
+      for (i, config) in self.config.iter().enumerate() {
+        let starts = if i == 0 { self.starts.clone() } else { vec![] };
+        if let Err(e) = self.run(&config.as_path(), &starts) {
+          eprintln!("{}", e);
+          exit(1);
+        }
+      }
+      if self.cron.is_none() {
+        break;
       }
     }
   }

src/utils/traits/mod.rs

@@ -1,3 +1,5 @@
 pub(crate) use command_config::CommandConfig;
+pub(crate) use wait_schedule::WaitSchedule;
 
 mod command_config;
+mod wait_schedule;

src/utils/traits/wait_schedule.rs

@@ -0,0 +1,29 @@
+use chrono::Local;
+use cron::Schedule;
+
+pub trait WaitSchedule<T> {
+  fn wait(&self, timezone: T);
+}
+
+impl WaitSchedule<Local> for Option<Schedule> {
+  fn wait(&self, timezone: Local) {
+    if let Some(cron) = self {
+      cron.wait(timezone);
+    }
+  }
+}
+
+impl WaitSchedule<Local> for Schedule {
+  fn wait(&self, timezone: Local) {
+    let date = self
+      .upcoming(timezone)
+      .next()
+      .expect("Cannot get upcoming cron date");
+
+    std::thread::sleep(
+      (date - Local::now())
+        .to_std()
+        .expect("Cannot transform Duration"),
+    );
+  }
+}