Merge pull request #136 from YJDoc2/main

Document Info module

docs/doc-draft.md

@@ -95,4 +95,13 @@ This also provides implementation for Linux syscalls for the trait.
 
 ## Capabilities
 
+This has functions related to set and reset specific capabilities, as well as to drop extra privileges
+
 - [Simple explanation of capabilities](https://blog.container-solutions.com/linux-capabilities-in-practice)
+- [man page for capabilities](https://man7.org/linux/man-pages/man7/capabilities.7.html)
+
+## Info
+
+This is primarily for printing info about system running youki, such as OS release, architecture, cpu info, cgroups info etc. , as this info can be helpful when reporting issues.
+
+- [about /etc/os-release](https://www.freedesktop.org/software/systemd/man/os-release.html)

src/info.rs

@@ -1,3 +1,4 @@
+//! Contains functions related to printing information about system running Youki
 use std::{fs, path::Path};
 
 use anyhow::Result;
@@ -21,17 +22,20 @@ impl Info {
     }
 }
 
+/// print Version of Youki
 pub fn print_youki() {
     println!("{:<18}{}", "Version", env!("CARGO_PKG_VERSION"));
 }
 
+/// Print Kernel Release, Version and Architecture
 pub fn print_kernel() {
     let uname = nix::sys::utsname::uname();
     println!("{:<18}{}", "Kernel-Release", uname.release());
     println!("{:<18}{}", "Kernel-Version", uname.version());
     println!("{:<18}{}", "Architecture", uname.machine());
 }
 
+/// Prints OS Distribution information
 // see https://www.freedesktop.org/software/systemd/man/os-release.html
 pub fn print_os() {
     if let Some(os) = try_read_os_from("/etc/os-release") {
@@ -41,6 +45,7 @@ pub fn print_os() {
     }
 }
 
+/// Helper function to read the OS Distribution info
 fn try_read_os_from<P: AsRef<Path>>(path: P) -> Option<String> {
     let os_release = path.as_ref();
     if !os_release.exists() {
@@ -69,6 +74,7 @@ fn try_read_os_from<P: AsRef<Path>>(path: P) -> Option<String> {
     None
 }
 
+/// Helper function to find keyword values in OS info string
 fn find_parameter<'a>(content: &'a str, param_name: &str) -> Option<&'a str> {
     let param_value = content
         .lines()
@@ -82,6 +88,7 @@ fn find_parameter<'a>(content: &'a str, param_name: &str) -> Option<&'a str> {
     None
 }
 
+/// Print Hardware information of system
 pub fn print_hardware() {
     if let Ok(cpu_info) = CpuInfo::new() {
         println!("{:<18}{}", "Cores", cpu_info.num_cores());
@@ -96,6 +103,7 @@ pub fn print_hardware() {
     }
 }
 
+/// Print cgroups info of system
 pub fn print_cgroups() {
     if let Ok(cgroup_fs) = cgroups::common::get_supported_cgroup_fs() {
         let cgroup_fs: Vec<String> = cgroup_fs.into_iter().map(|c| c.to_string()).collect();