src/repositories/release.rs

   1 use std::convert::{TryFrom, TryInto};
   2 use std::fmt::Display;
   3 use std::io::{BufRead, BufReader};
   4
   5 use anyhow::{bail, format_err, Error};
   6
   7 /// The code names of Debian releases. Does not include `sid`.
   8 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
   9 pub enum DebianCodename {
  10     Lenny = 5,
  11     Squeeze,
  12     Wheezy,
  13     Jessie,
  14     Stretch,
  15     Buster,
  16     Bullseye,
  17     Bookworm,
  18     Trixie,
  19 }
  20
  21 impl DebianCodename {
  22     pub fn next(&self) -> Option<Self> {
  23         match (*self as u8 + 1).try_into() {
  24             Ok(codename) => Some(codename),
  25             Err(_) => None,
  26         }
  27     }
  28 }
  29
  30 impl TryFrom<&str> for DebianCodename {
  31     type Error = Error;
  32
  33     fn try_from(string: &str) -> Result<Self, Error> {
  34         match string {
  35             "lenny" => Ok(DebianCodename::Lenny),
  36             "squeeze" => Ok(DebianCodename::Squeeze),
  37             "wheezy" => Ok(DebianCodename::Wheezy),
  38             "jessie" => Ok(DebianCodename::Jessie),
  39             "stretch" => Ok(DebianCodename::Stretch),
  40             "buster" => Ok(DebianCodename::Buster),
  41             "bullseye" => Ok(DebianCodename::Bullseye),
  42             "bookworm" => Ok(DebianCodename::Bookworm),
  43             "trixie" => Ok(DebianCodename::Trixie),
  44             _ => bail!("unknown Debian code name '{}'", string),
  45         }
  46     }
  47 }
  48
  49 impl TryFrom<u8> for DebianCodename {
  50     type Error = Error;
  51
  52     fn try_from(number: u8) -> Result<Self, Error> {
  53         match number {
  54             5 => Ok(DebianCodename::Lenny),
  55             6 => Ok(DebianCodename::Squeeze),
  56             7 => Ok(DebianCodename::Wheezy),
  57             8 => Ok(DebianCodename::Jessie),
  58             9 => Ok(DebianCodename::Stretch),
  59             10 => Ok(DebianCodename::Buster),
  60             11 => Ok(DebianCodename::Bullseye),
  61             12 => Ok(DebianCodename::Bookworm),
  62             13 => Ok(DebianCodename::Trixie),
  63             _ => bail!("unknown Debian release number '{}'", number),
  64         }
  65     }
  66 }
  67
  68 impl Display for DebianCodename {
  69     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
  70         match self {
  71             DebianCodename::Lenny => write!(f, "lenny"),
  72             DebianCodename::Squeeze => write!(f, "squeeze"),
  73             DebianCodename::Wheezy => write!(f, "wheezy"),
  74             DebianCodename::Jessie => write!(f, "jessie"),
  75             DebianCodename::Stretch => write!(f, "stretch"),
  76             DebianCodename::Buster => write!(f, "buster"),
  77             DebianCodename::Bullseye => write!(f, "bullseye"),
  78             DebianCodename::Bookworm => write!(f, "bookworm"),
  79             DebianCodename::Trixie => write!(f, "trixie"),
  80         }
  81     }
  82 }
  83
  84 /// Read the `VERSION_CODENAME` from `/etc/os-release`.
  85 pub fn get_current_release_codename() -> Result<DebianCodename, Error> {
  86     let raw = std::fs::read("/etc/os-release")
  87         .map_err(|err| format_err!("unable to read '/etc/os-release' - {}", err))?;
  88
  89     let reader = BufReader::new(&*raw);
  90
  91     for line in reader.lines() {
  92         let line = line.map_err(|err| format_err!("unable to read '/etc/os-release' - {}", err))?;
  93
  94         if let Some(codename) = line.strip_prefix("VERSION_CODENAME=") {
  95             let codename = codename.trim_matches(&['"', '\''][..]);
  96             return codename.try_into();
  97         }
  98     }
  99
 100     bail!("unable to parse codename from '/etc/os-release'");
 101 }