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src/bin/proxmox-backup-client.rs: add functionality to mount pxar archive.

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This adds the basic functionality to mount an archive stored in a repository
locally via fuse.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
This commit is contained in:
Christian Ebner
2019-09-19 16:33:09 +02:00
committed by Dietmar Maurer
parent 2fa91f5221
commit 70235f72f4
1 changed files with 167 additions and 2 deletions
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169
src/bin/proxmox-backup-client.rs
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@ -2,10 +2,12 @@
extern crate proxmox_backup;
use failure::*;
//use std::os::unix::io::AsRawFd;
use nix::unistd::{fork, ForkResult, pipe};
use std::os::unix::io::RawFd;
use chrono::{Local, Utc, TimeZone};
use std::path::{Path, PathBuf};
use std::collections::{HashSet, HashMap};
use std::ffi::OsStr;
use std::io::{BufReader, Read, Write, Seek, SeekFrom};
use std::os::unix::fs::OpenOptionsExt;
@ -1634,6 +1636,151 @@ fn key_mgmt_cli() -> CliCommandMap {
cmd_def
}
fn mount(
param: Value,
_info: &ApiMethod,
_rpcenv: &mut dyn RpcEnvironment,
) -> Result<Value, Error> {
let verbose = param["verbose"].as_bool().unwrap_or(false);
if verbose {
// This will stay in foreground with debug output enabled as None is
// passed for the RawFd.
return async_main(mount_do(param, None));
}
// Process should be deamonized.
// Make sure to fork before the async runtime is instantiated to avoid troubles.
let pipe = pipe()?;
match fork() {
Ok(ForkResult::Parent { child: _, .. }) => {
nix::unistd::close(pipe.1).unwrap();
// Blocks the parent process until we are ready to go in the child
let _res = nix::unistd::read(pipe.0, &mut [0]).unwrap();
Ok(Value::Null)
}
Ok(ForkResult::Child) => {
nix::unistd::close(pipe.0).unwrap();
nix::unistd::setsid().unwrap();
async_main(mount_do(param, Some(pipe.1)))
}
Err(_) => bail!("failed to daemonize process"),
}
}
async fn mount_do(param: Value, pipe: Option<RawFd>) -> Result<Value, Error> {
let repo = extract_repository_from_value(&param)?;
let archive_name = tools::required_string_param(&param, "archive-name")?;
let target = tools::required_string_param(&param, "target")?;
let client = HttpClient::new(repo.host(), repo.user(), None)?;
record_repository(&repo);
let path = tools::required_string_param(&param, "snapshot")?;
let (backup_type, backup_id, backup_time) = if path.matches('/').count() == 1 {
let group = BackupGroup::parse(path)?;
let path = format!("api2/json/admin/datastore/{}/snapshots", repo.store());
let result = client.get(&path, Some(json!({
"backup-type": group.backup_type(),
"backup-id": group.backup_id(),
}))).await?;
let list = result["data"].as_array().unwrap();
if list.len() == 0 {
bail!("backup group '{}' does not contain any snapshots:", path);
}
let epoch = list[0]["backup-time"].as_i64().unwrap();
let backup_time = Utc.timestamp(epoch, 0);
(group.backup_type().to_owned(), group.backup_id().to_owned(), backup_time)
} else {
let snapshot = BackupDir::parse(path)?;
(snapshot.group().backup_type().to_owned(), snapshot.group().backup_id().to_owned(), snapshot.backup_time())
};
let keyfile = param["keyfile"].as_str().map(|p| PathBuf::from(p));
let crypt_config = match keyfile {
None => None,
Some(path) => {
let (key, _) = load_and_decrtypt_key(&path, get_encryption_key_password)?;
Some(Arc::new(CryptConfig::new(key)?))
}
};
let server_archive_name = if archive_name.ends_with(".pxar") {
format!("{}.didx", archive_name)
} else {
bail!("Can only mount pxar archives.");
};
let client = client
.start_backup_reader(repo.store(), &backup_type, &backup_id, backup_time, true)
.await?;
let tmpfile = std::fs::OpenOptions::new()
.write(true)
.read(true)
.custom_flags(libc::O_TMPFILE)
.open("/tmp")?;
let backup_index_data = download_index_blob(client.clone(), crypt_config.clone()).await?;
let backup_index: Value = serde_json::from_slice(&backup_index_data[..])?;
if server_archive_name.ends_with(".didx") {
let tmpfile = client.download(&server_archive_name, tmpfile).await?;
let index = DynamicIndexReader::new(tmpfile)
.map_err(|err| format_err!("unable to read dynamic index '{}' - {}", archive_name, err))?;
// Note: do not use values stored in index (not trusted) - instead, computed them again
let (csum, size) = index.compute_csum();
verify_index_file(&backup_index, &server_archive_name, &csum, size)?;
let most_used = index.find_most_used_chunks(8);
let chunk_reader = RemoteChunkReader::new(client.clone(), crypt_config, most_used);
let reader = BufferedDynamicReader::new(index, chunk_reader);
let decoder =
pxar::Decoder::<Box<dyn pxar::fuse::ReadSeek>, fn(&Path) -> Result<(), Error>>::new(
Box::new(reader),
|_| Ok(()),
)?;
let options = OsStr::new("ro,default_permissions");
let mut session = pxar::fuse::Session::from_decoder(decoder, &options, pipe.is_none())
.map_err(|err| format_err!("pxar mount failed: {}", err))?;
// Mount the session but not call fuse deamonize as this will cause
// issues with the runtime after the fork
let deamonize = false;
session.mount(&Path::new(target), deamonize)?;
if let Some(pipe) = pipe {
nix::unistd::chdir(Path::new("/")).unwrap();
// Finish creation of deamon by redirecting filedescriptors.
let nullfd = nix::fcntl::open(
"/dev/null",
nix::fcntl::OFlag::O_RDWR,
nix::sys::stat::Mode::empty(),
).unwrap();
nix::unistd::dup2(nullfd, 0).unwrap();
nix::unistd::dup2(nullfd, 1).unwrap();
nix::unistd::dup2(nullfd, 2).unwrap();
if nullfd > 2 {
nix::unistd::close(nullfd).unwrap();
}
// Signal the parent process that we are done with the setup and it can
// terminate.
nix::unistd::write(pipe, &mut [0u8])?;
nix::unistd::close(pipe).unwrap();
}
let multithreaded = true;
session.run_loop(multithreaded)?;
} else {
bail!("unknown archive file extension (expected .pxar)");
}
Ok(Value::Null)
}
fn main() {
let backup_source_schema: Arc<Schema> = Arc::new(
@ -1841,6 +1988,23 @@ We do not extraxt '.pxar' archives when writing to stdandard output.
.optional("repository", REPO_URL_SCHEMA.clone())
))
.completion_cb("repository", complete_repository);
let mount_cmd_def = CliCommand::new(
ApiMethod::new(
mount,
ObjectSchema::new("Mount pxar archive.")
.required("snapshot", StringSchema::new("Group/Snapshot path."))
.required("archive-name", StringSchema::new("Backup archive name."))
.required("target", StringSchema::new("Target directory path."))
.optional("repository", REPO_URL_SCHEMA.clone())
.optional("keyfile", StringSchema::new("Path to encryption key."))
.optional("verbose", BooleanSchema::new("Verbose output.").default(false))
))
.arg_param(vec!["snapshot", "archive-name", "target"])
.completion_cb("repository", complete_repository)
.completion_cb("snapshot", complete_group_or_snapshot)
.completion_cb("archive-name", complete_archive_name)
.completion_cb("target", tools::complete_file_name);
let cmd_def = CliCommandMap::new()
.insert("backup".to_owned(), backup_cmd_def.into())
@ -1856,7 +2020,8 @@ We do not extraxt '.pxar' archives when writing to stdandard output.
.insert("snapshots".to_owned(), snapshots_cmd_def.into())
.insert("files".to_owned(), files_cmd_def.into())
.insert("status".to_owned(), status_cmd_def.into())
.insert("key".to_owned(), key_mgmt_cli().into());
.insert("key".to_owned(), key_mgmt_cli().into())
.insert("mount".to_owned(), mount_cmd_def.into());
run_cli_command(cmd_def.into());
}