proxmox-backup/src/tools/logrotate.rs
Fabian Grünbichler 81281d04a4 clippy: fix/allow identity_op
Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
2021-01-20 16:23:54 +01:00

215 lines
6.6 KiB
Rust

use std::path::{Path, PathBuf};
use std::fs::{File, rename};
use std::os::unix::io::{FromRawFd, IntoRawFd};
use std::io::Read;
use anyhow::{bail, Error};
use nix::unistd;
use proxmox::tools::fs::{CreateOptions, make_tmp_file};
/// Used for rotating log files and iterating over them
pub struct LogRotate {
base_path: PathBuf,
compress: bool,
}
impl LogRotate {
/// Creates a new instance if the path given is a valid file name
/// (iow. does not end with ..)
/// 'compress' decides if compresses files will be created on
/// rotation, and if it will search '.zst' files when iterating
pub fn new<P: AsRef<Path>>(path: P, compress: bool) -> Option<Self> {
if path.as_ref().file_name().is_some() {
Some(Self {
base_path: path.as_ref().to_path_buf(),
compress,
})
} else {
None
}
}
/// Returns an iterator over the logrotated file names that exist
pub fn file_names(&self) -> LogRotateFileNames {
LogRotateFileNames {
base_path: self.base_path.clone(),
count: 0,
compress: self.compress
}
}
/// Returns an iterator over the logrotated file handles
pub fn files(&self) -> LogRotateFiles {
LogRotateFiles {
file_names: self.file_names(),
}
}
fn compress(source_path: &PathBuf, target_path: &PathBuf, options: &CreateOptions) -> Result<(), Error> {
let mut source = File::open(source_path)?;
let (fd, tmp_path) = make_tmp_file(target_path, options.clone())?;
let target = unsafe { File::from_raw_fd(fd.into_raw_fd()) };
let mut encoder = match zstd::stream::write::Encoder::new(target, 0) {
Ok(encoder) => encoder,
Err(err) => {
let _ = unistd::unlink(&tmp_path);
bail!("creating zstd encoder failed - {}", err);
}
};
if let Err(err) = std::io::copy(&mut source, &mut encoder) {
let _ = unistd::unlink(&tmp_path);
bail!("zstd encoding failed for file {:?} - {}", target_path, err);
}
if let Err(err) = encoder.finish() {
let _ = unistd::unlink(&tmp_path);
bail!("zstd finish failed for file {:?} - {}", target_path, err);
}
if let Err(err) = rename(&tmp_path, target_path) {
let _ = unistd::unlink(&tmp_path);
bail!("rename failed for file {:?} - {}", target_path, err);
}
if let Err(err) = unistd::unlink(source_path) {
bail!("unlink failed for file {:?} - {}", source_path, err);
}
Ok(())
}
/// Rotates the files up to 'max_files'
/// if the 'compress' option was given it will compress the newest file
///
/// e.g. rotates
/// foo.2.zst => foo.3.zst
/// foo.1 => foo.2.zst
/// foo => foo.1
pub fn do_rotate(&mut self, options: CreateOptions, max_files: Option<usize>) -> Result<(), Error> {
let mut filenames: Vec<PathBuf> = self.file_names().collect();
if filenames.is_empty() {
return Ok(()); // no file means nothing to rotate
}
let count = filenames.len() + 1;
let mut next_filename = self.base_path.clone().canonicalize()?.into_os_string();
next_filename.push(format!(".{}", filenames.len()));
if self.compress && count > 2 {
next_filename.push(".zst");
}
filenames.push(PathBuf::from(next_filename));
for i in (0..count-1).rev() {
if self.compress
&& filenames[i].extension() != Some(std::ffi::OsStr::new("zst"))
&& filenames[i+1].extension() == Some(std::ffi::OsStr::new("zst"))
{
Self::compress(&filenames[i], &filenames[i+1], &options)?;
} else {
rename(&filenames[i], &filenames[i+1])?;
}
}
if let Some(max_files) = max_files {
for file in filenames.iter().skip(max_files) {
if let Err(err) = unistd::unlink(file) {
eprintln!("could not remove {:?}: {}", &file, err);
}
}
}
Ok(())
}
pub fn rotate(
&mut self,
max_size: u64,
options: Option<CreateOptions>,
max_files: Option<usize>
) -> Result<bool, Error> {
let options = match options {
Some(options) => options,
None => {
let backup_user = crate::backup::backup_user()?;
CreateOptions::new().owner(backup_user.uid).group(backup_user.gid)
},
};
let metadata = match self.base_path.metadata() {
Ok(metadata) => metadata,
Err(err) if err.kind() == std::io::ErrorKind::NotFound => return Ok(false),
Err(err) => bail!("unable to open task archive - {}", err),
};
if metadata.len() > max_size {
self.do_rotate(options, max_files)?;
Ok(true)
} else {
Ok(false)
}
}
}
/// Iterator over logrotated file names
pub struct LogRotateFileNames {
base_path: PathBuf,
count: usize,
compress: bool,
}
impl Iterator for LogRotateFileNames {
type Item = PathBuf;
fn next(&mut self) -> Option<Self::Item> {
if self.count > 0 {
let mut path: std::ffi::OsString = self.base_path.clone().into();
path.push(format!(".{}", self.count));
self.count += 1;
if Path::new(&path).is_file() {
Some(path.into())
} else if self.compress {
path.push(".zst");
if Path::new(&path).is_file() {
Some(path.into())
} else {
None
}
} else {
None
}
} else if self.base_path.is_file() {
self.count += 1;
Some(self.base_path.to_path_buf())
} else {
None
}
}
}
/// Iterator over logrotated files by returning a boxed reader
pub struct LogRotateFiles {
file_names: LogRotateFileNames,
}
impl Iterator for LogRotateFiles {
type Item = Box<dyn Read + Send>;
fn next(&mut self) -> Option<Self::Item> {
let filename = self.file_names.next()?;
let file = File::open(&filename).ok()?;
if filename.extension() == Some(std::ffi::OsStr::new("zst")) {
let encoder = zstd::stream::read::Decoder::new(file).ok()?;
return Some(Box::new(encoder));
}
Some(Box::new(file))
}
}