Function read_sysusers

crates/sysusers/src/lib.rs:214–268

Read all tmpfiles.d entries in the target directory, and return a mapping from (file path) => (single tmpfiles.d entry line)

(rootfs: &Dir)

/// Read all tmpfiles.d entries in the target directory, and return a mapping
/// from (file path) => (single tmpfiles.d entry line)
pub fn read_sysusers(rootfs: &Dir) -> Result<Vec<SysusersEntry>> {
    let Some(d) = rootfs.open_dir_optional(SYSUSERSD)? else {
        return Ok(Default::default());
    };
    let d = DirUtf8::from_cap_std(d);
    let mut result = Vec::new();
    let mut found_users = BTreeSet::new();
    let mut found_groups = BTreeSet::new();
    for name in d.filenames_sorted()? {
        let Some("conf") = Utf8Path::new(&name).extension() else {
            continue;
        };
        let r = d.open(&name).map(BufReader::new)?;
        for line in r.lines() {
            let line = line?;
            if line.is_empty() || line.starts_with("#") {
                continue;
            }
            let Some(e) = SysusersEntry::parse(&line).map_err(|e| Error::ParseFailureInFile {
                path: name.clone().into(),
                err: e.to_string(),
            })?
            else {
                continue;
            };
            match e {
                SysusersEntry::User {
                    ref name, ref pgid, ..
                } if !found_users.contains(name.as_str()) => {
                    found_users.insert(name.clone());
                    found_groups.insert(name.clone());
                    // Users implicitly create a group with the same name
                    let pgid = pgid.as_ref().and_then(|g| match g {
                        GroupReference::Numeric(n) => Some(IdSource::Numeric(*n)),
                        GroupReference::Path(p) => Some(IdSource::Path(p.clone())),
                        GroupReference::Name(_) => None,
                    });
                    result.push(SysusersEntry::Group {
                        name: name.clone(),
                        id: pgid,
                    });
                    result.push(e);
                }
                SysusersEntry::Group { ref name, .. } if !found_groups.contains(name.as_str()) => {
                    found_groups.insert(name.clone());
                    result.push(e);
                }
                _ => {
                    // Ignore others.
                }
            }
        }
    }
    Ok(result)
}

/// The result of analyzing /etc/{passwd,group} in a root vs systemd-sysusers.
#[derive(Debug, Default)]