add cgroup enter

src/bin/izoli.rs

@@ -12,4 +12,6 @@ fn main() {
     println!("{:?}", cgroup.get_stat());
     println!("{:?}", cgroup.get_max_depth());
     println!("{:?}", cgroup.get_max_descendants());
+
+    cgroup.enter().unwrap();
 }

src/cgroup/cgroup.rs

@@ -30,6 +30,12 @@ impl CGroup {
         fs::create_dir_all(root)
     }
 
+    pub fn enter(&self) -> Result<(), std::io::Error> {
+        let pid = std::process::id();
+
+        self.add_procs(vec![pid])
+    }
+
     pub fn read(&self, name: &str) -> Result<String, std::io::Error> {
         let path = self.get_file_path(name);
         let mut file = File::open(path)?;