src/api2/backup.rs

   1 use anyhow::{bail, format_err, Error};
   2 use futures::*;
   3 use hyper::header::{HeaderValue, UPGRADE};
   4 use hyper::http::request::Parts;
   5 use hyper::{Body, Response, StatusCode};
   6 use serde_json::{json, Value};
   7
   8 use proxmox::{sortable, identity, list_subdirs_api_method};
   9 use proxmox::api::{ApiResponseFuture, ApiHandler, ApiMethod, Router, RpcEnvironment, Permission};
  10 use proxmox::api::router::SubdirMap;
  11 use proxmox::api::schema::*;
  12
  13 use crate::tools::{self, WrappedReaderStream};
  14 use crate::server::{WorkerTask, H2Service};
  15 use crate::backup::*;
  16 use crate::api2::types::*;
  17 use crate::config::acl::PRIV_DATASTORE_ALLOCATE_SPACE;
  18
  19 mod environment;
  20 use environment::*;
  21
  22 mod upload_chunk;
  23 use upload_chunk::*;
  24
  25 pub const ROUTER: Router = Router::new()
  26     .upgrade(&API_METHOD_UPGRADE_BACKUP);
  27
  28 #[sortable]
  29 pub const API_METHOD_UPGRADE_BACKUP: ApiMethod = ApiMethod::new(
  30     &ApiHandler::AsyncHttp(&upgrade_to_backup_protocol),
  31     &ObjectSchema::new(
  32         concat!("Upgraded to backup protocol ('", PROXMOX_BACKUP_PROTOCOL_ID_V1!(), "')."),
  33         &sorted!([
  34             ("store", false, &DATASTORE_SCHEMA),
  35             ("backup-type", false, &BACKUP_TYPE_SCHEMA),
  36             ("backup-id", false, &BACKUP_ID_SCHEMA),
  37             ("backup-time", false, &BACKUP_TIME_SCHEMA),
  38             ("debug", true, &BooleanSchema::new("Enable verbose debug logging.").schema()),
  39         ]),
  40     )
  41 ).access(None, &Permission::Privilege(&["datastore", "{store}"], PRIV_DATASTORE_ALLOCATE_SPACE, false));
  42
  43 fn upgrade_to_backup_protocol(
  44     parts: Parts,
  45     req_body: Body,
  46     param: Value,
  47     _info: &ApiMethod,
  48     rpcenv: Box<dyn RpcEnvironment>,
  49 ) -> ApiResponseFuture {
  50
  51     async move {
  52     let debug = param["debug"].as_bool().unwrap_or(false);
  53
  54     let store = tools::required_string_param(&param, "store")?.to_owned();
  55     let datastore = DataStore::lookup_datastore(&store)?;
  56
  57     let backup_type = tools::required_string_param(&param, "backup-type")?;
  58     let backup_id = tools::required_string_param(&param, "backup-id")?;
  59     let backup_time = tools::required_integer_param(&param, "backup-time")?;
  60
  61     let protocols = parts
  62         .headers
  63         .get("UPGRADE")
  64         .ok_or_else(|| format_err!("missing Upgrade header"))?
  65         .to_str()?;
  66
  67     if protocols != PROXMOX_BACKUP_PROTOCOL_ID_V1!() {
  68         bail!("invalid protocol name");
  69     }
  70
  71     if parts.version >=  http::version::Version::HTTP_2 {
  72         bail!("unexpected http version '{:?}' (expected version < 2)", parts.version);
  73     }
  74
  75     let worker_id = format!("{}_{}_{}", store, backup_type, backup_id);
  76
  77     let username = rpcenv.get_user().unwrap();
  78     let env_type = rpcenv.env_type();
  79
  80     let backup_group = BackupGroup::new(backup_type, backup_id);
  81     let last_backup = BackupInfo::last_backup(&datastore.base_path(), &backup_group).unwrap_or(None);
  82     let backup_dir = BackupDir::new_with_group(backup_group, backup_time);
  83
  84     if let Some(last) = &last_backup {
  85         if backup_dir.backup_time() <= last.backup_dir.backup_time() {
  86             bail!("backup timestamp is older than last backup.");
  87         }
  88         // fixme: abort if last backup is still running - howto test?
  89         // Idea: write upid into a file inside snapshot dir. then test if
  90         // it is still running here.
  91     }
  92
  93     let (path, is_new) = datastore.create_backup_dir(&backup_dir)?;
  94     if !is_new { bail!("backup directorty already exists."); }
  95
  96     WorkerTask::spawn("backup", Some(worker_id), &username.clone(), true, move |worker| {
  97         let mut env = BackupEnvironment::new(
  98             env_type, username.clone(), worker.clone(), datastore, backup_dir);
  99
 100         env.debug = debug;
 101         env.last_backup = last_backup;
 102
 103         env.log(format!("starting new backup on datastore '{}': {:?}", store, path));
 104
 105         let service = H2Service::new(env.clone(), worker.clone(), &BACKUP_API_ROUTER, debug);
 106
 107         let abort_future = worker.abort_future();
 108
 109         let env2 = env.clone();
 110
 111         let mut req_fut = req_body
 112             .on_upgrade()
 113             .map_err(Error::from)
 114             .and_then(move |conn| {
 115                 env2.debug("protocol upgrade done");
 116
 117                 let mut http = hyper::server::conn::Http::new();
 118                 http.http2_only(true);
 119                 // increase window size: todo - find optiomal size
 120                 let window_size = 32*1024*1024; // max = (1 << 31) - 2
 121                 http.http2_initial_stream_window_size(window_size);
 122                 http.http2_initial_connection_window_size(window_size);
 123
 124                 http.serve_connection(conn, service)
 125                     .map_err(Error::from)
 126             });
 127         let mut abort_future = abort_future
 128             .map(|_| Err(format_err!("task aborted")));
 129
 130         async move {
 131             let res = select!{
 132                 req = req_fut => req,
 133                 abrt = abort_future => abrt,
 134             };
 135
 136             match (res, env.ensure_finished()) {
 137                 (Ok(_), Ok(())) => {
 138                     env.log("backup finished sucessfully");
 139                     Ok(())
 140                 },
 141                 (Err(err), Ok(())) => {
 142                     // ignore errors after finish
 143                     env.log(format!("backup had errors but finished: {}", err));
 144                     Ok(())
 145                 },
 146                 (Ok(_), Err(err)) => {
 147                     env.log(format!("backup ended and finish failed: {}", err));
 148                     env.log("removing unfinished backup");
 149                     env.remove_backup()?;
 150                     Err(err)
 151                 },
 152                 (Err(err), Err(_)) => {
 153                     env.log(format!("backup failed: {}", err));
 154                     env.log("removing failed backup");
 155                     env.remove_backup()?;
 156                     Err(err)
 157                 },
 158             }
 159         }
 160     })?;
 161
 162     let response = Response::builder()
 163         .status(StatusCode::SWITCHING_PROTOCOLS)
 164         .header(UPGRADE, HeaderValue::from_static(PROXMOX_BACKUP_PROTOCOL_ID_V1!()))
 165         .body(Body::empty())?;
 166
 167     Ok(response)
 168     }.boxed()
 169 }
 170
 171 pub const BACKUP_API_SUBDIRS: SubdirMap = &[
 172     (
 173         "blob", &Router::new()
 174             .upload(&API_METHOD_UPLOAD_BLOB)
 175     ),
 176     (
 177         "dynamic_chunk", &Router::new()
 178             .upload(&API_METHOD_UPLOAD_DYNAMIC_CHUNK)
 179     ),
 180     (
 181         "dynamic_close", &Router::new()
 182             .post(&API_METHOD_CLOSE_DYNAMIC_INDEX)
 183     ),
 184     (
 185         "dynamic_index", &Router::new()
 186             .download(&API_METHOD_DYNAMIC_CHUNK_INDEX)
 187             .post(&API_METHOD_CREATE_DYNAMIC_INDEX)
 188             .put(&API_METHOD_DYNAMIC_APPEND)
 189     ),
 190     (
 191         "finish", &Router::new()
 192             .post(
 193                 &ApiMethod::new(
 194                     &ApiHandler::Sync(&finish_backup),
 195                     &ObjectSchema::new("Mark backup as finished.", &[])
 196                 )
 197             )
 198     ),
 199     (
 200         "fixed_chunk", &Router::new()
 201             .upload(&API_METHOD_UPLOAD_FIXED_CHUNK)
 202     ),
 203     (
 204         "fixed_close", &Router::new()
 205             .post(&API_METHOD_CLOSE_FIXED_INDEX)
 206     ),
 207     (
 208         "fixed_index", &Router::new()
 209             .download(&API_METHOD_FIXED_CHUNK_INDEX)
 210             .post(&API_METHOD_CREATE_FIXED_INDEX)
 211             .put(&API_METHOD_FIXED_APPEND)
 212     ),
 213     (
 214         "speedtest", &Router::new()
 215             .upload(&API_METHOD_UPLOAD_SPEEDTEST)
 216     ),
 217 ];
 218
 219 pub const BACKUP_API_ROUTER: Router = Router::new()
 220     .get(&list_subdirs_api_method!(BACKUP_API_SUBDIRS))
 221     .subdirs(BACKUP_API_SUBDIRS);
 222
 223 #[sortable]
 224 pub const API_METHOD_CREATE_DYNAMIC_INDEX: ApiMethod = ApiMethod::new(
 225     &ApiHandler::Sync(&create_dynamic_index),
 226     &ObjectSchema::new(
 227         "Create dynamic chunk index file.",
 228         &sorted!([
 229             ("archive-name", false, &crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA),
 230         ]),
 231     )
 232 );
 233
 234 fn create_dynamic_index(
 235     param: Value,
 236     _info: &ApiMethod,
 237     rpcenv: &mut dyn RpcEnvironment,
 238 ) -> Result<Value, Error> {
 239
 240     let env: &BackupEnvironment = rpcenv.as_ref();
 241
 242     let name = tools::required_string_param(&param, "archive-name")?.to_owned();
 243
 244     let archive_name = name.clone();
 245     if !archive_name.ends_with(".didx") {
 246         bail!("wrong archive extension: '{}'", archive_name);
 247     }
 248
 249     let mut path = env.backup_dir.relative_path();
 250     path.push(archive_name);
 251
 252     let index = env.datastore.create_dynamic_writer(&path)?;
 253     let wid = env.register_dynamic_writer(index, name)?;
 254
 255     env.log(format!("created new dynamic index {} ({:?})", wid, path));
 256
 257     Ok(json!(wid))
 258 }
 259
 260 #[sortable]
 261 pub const API_METHOD_CREATE_FIXED_INDEX: ApiMethod = ApiMethod::new(
 262     &ApiHandler::Sync(&create_fixed_index),
 263     &ObjectSchema::new(
 264         "Create fixed chunk index file.",
 265         &sorted!([
 266             ("archive-name", false, &crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA),
 267             ("size", false, &IntegerSchema::new("File size.")
 268              .minimum(1)
 269              .schema()
 270             ),
 271         ]),
 272     )
 273 );
 274
 275 fn create_fixed_index(
 276     param: Value,
 277     _info: &ApiMethod,
 278     rpcenv: &mut dyn RpcEnvironment,
 279 ) -> Result<Value, Error> {
 280
 281     let env: &BackupEnvironment = rpcenv.as_ref();
 282
 283     println!("PARAM: {:?}", param);
 284
 285     let name = tools::required_string_param(&param, "archive-name")?.to_owned();
 286     let size = tools::required_integer_param(&param, "size")? as usize;
 287
 288     let archive_name = name.clone();
 289     if !archive_name.ends_with(".fidx") {
 290         bail!("wrong archive extension: '{}'", archive_name);
 291     }
 292
 293     let mut path = env.backup_dir.relative_path();
 294     path.push(archive_name);
 295
 296     let chunk_size = 4096*1024; // todo: ??
 297
 298     let index = env.datastore.create_fixed_writer(&path, size, chunk_size)?;
 299     let wid = env.register_fixed_writer(index, name, size, chunk_size as u32)?;
 300
 301     env.log(format!("created new fixed index {} ({:?})", wid, path));
 302
 303     Ok(json!(wid))
 304 }
 305
 306 #[sortable]
 307 pub const API_METHOD_DYNAMIC_APPEND: ApiMethod = ApiMethod::new(
 308     &ApiHandler::Sync(&dynamic_append),
 309     &ObjectSchema::new(
 310         "Append chunk to dynamic index writer.",
 311         &sorted!([
 312             (
 313                 "wid",
 314                 false,
 315                 &IntegerSchema::new("Dynamic writer ID.")
 316                     .minimum(1)
 317                     .maximum(256)
 318                     .schema()
 319             ),
 320             (
 321                 "digest-list",
 322                 false,
 323                 &ArraySchema::new("Chunk digest list.", &CHUNK_DIGEST_SCHEMA).schema()
 324             ),
 325             (
 326                 "offset-list",
 327                 false,
 328                 &ArraySchema::new(
 329                     "Chunk offset list.",
 330                     &IntegerSchema::new("Corresponding chunk offsets.")
 331                         .minimum(0)
 332                         .schema()
 333                 ).schema()
 334             ),
 335         ]),
 336     )
 337 );
 338
 339 fn dynamic_append (
 340     param: Value,
 341     _info: &ApiMethod,
 342     rpcenv: &mut dyn RpcEnvironment,
 343 ) -> Result<Value, Error> {
 344
 345     let wid = tools::required_integer_param(&param, "wid")? as usize;
 346     let digest_list = tools::required_array_param(&param, "digest-list")?;
 347     let offset_list = tools::required_array_param(&param, "offset-list")?;
 348
 349     if offset_list.len() != digest_list.len() {
 350         bail!("offset list has wrong length ({} != {})", offset_list.len(), digest_list.len());
 351     }
 352
 353     let env: &BackupEnvironment = rpcenv.as_ref();
 354
 355     env.debug(format!("dynamic_append {} chunks", digest_list.len()));
 356
 357     for (i, item) in digest_list.iter().enumerate() {
 358         let digest_str = item.as_str().unwrap();
 359         let digest = proxmox::tools::hex_to_digest(digest_str)?;
 360         let offset = offset_list[i].as_u64().unwrap();
 361         let size = env.lookup_chunk(&digest).ok_or_else(|| format_err!("no such chunk {}", digest_str))?;
 362
 363         env.dynamic_writer_append_chunk(wid, offset, size, &digest)?;
 364
 365         env.debug(format!("sucessfully added chunk {} to dynamic index {} (offset {}, size {})", digest_str, wid, offset, size));
 366     }
 367
 368     Ok(Value::Null)
 369 }
 370
 371 #[sortable]
 372 pub const API_METHOD_FIXED_APPEND: ApiMethod = ApiMethod::new(
 373     &ApiHandler::Sync(&fixed_append),
 374     &ObjectSchema::new(
 375         "Append chunk to fixed index writer.",
 376         &sorted!([
 377             (
 378                 "wid",
 379                 false,
 380                 &IntegerSchema::new("Fixed writer ID.")
 381                     .minimum(1)
 382                     .maximum(256)
 383                     .schema()
 384             ),
 385             (
 386                 "digest-list",
 387                 false,
 388                 &ArraySchema::new("Chunk digest list.", &CHUNK_DIGEST_SCHEMA).schema()
 389             ),
 390             (
 391                 "offset-list",
 392                 false,
 393                 &ArraySchema::new(
 394                     "Chunk offset list.",
 395                     &IntegerSchema::new("Corresponding chunk offsets.")
 396                         .minimum(0)
 397                         .schema()
 398                 ).schema()
 399             )
 400         ]),
 401     )
 402 );
 403
 404 fn fixed_append (
 405     param: Value,
 406     _info: &ApiMethod,
 407     rpcenv: &mut dyn RpcEnvironment,
 408 ) -> Result<Value, Error> {
 409
 410     let wid = tools::required_integer_param(&param, "wid")? as usize;
 411     let digest_list = tools::required_array_param(&param, "digest-list")?;
 412     let offset_list = tools::required_array_param(&param, "offset-list")?;
 413
 414     if offset_list.len() != digest_list.len() {
 415         bail!("offset list has wrong length ({} != {})", offset_list.len(), digest_list.len());
 416     }
 417
 418     let env: &BackupEnvironment = rpcenv.as_ref();
 419
 420     env.debug(format!("fixed_append {} chunks", digest_list.len()));
 421
 422     for (i, item) in digest_list.iter().enumerate() {
 423         let digest_str = item.as_str().unwrap();
 424         let digest = proxmox::tools::hex_to_digest(digest_str)?;
 425         let offset = offset_list[i].as_u64().unwrap();
 426         let size = env.lookup_chunk(&digest).ok_or_else(|| format_err!("no such chunk {}", digest_str))?;
 427
 428         env.fixed_writer_append_chunk(wid, offset, size, &digest)?;
 429
 430         env.debug(format!("sucessfully added chunk {} to fixed index {} (offset {}, size {})", digest_str, wid, offset, size));
 431     }
 432
 433     Ok(Value::Null)
 434 }
 435
 436 #[sortable]
 437 pub const API_METHOD_CLOSE_DYNAMIC_INDEX: ApiMethod = ApiMethod::new(
 438     &ApiHandler::Sync(&close_dynamic_index),
 439     &ObjectSchema::new(
 440         "Close dynamic index writer.",
 441         &sorted!([
 442             (
 443                 "wid",
 444                 false,
 445                 &IntegerSchema::new("Dynamic writer ID.")
 446                     .minimum(1)
 447                     .maximum(256)
 448                     .schema()
 449             ),
 450             (
 451                 "chunk-count",
 452                 false,
 453                 &IntegerSchema::new("Chunk count. This is used to verify that the server got all chunks.")
 454                     .minimum(1)
 455                     .schema()
 456             ),
 457             (
 458                 "size",
 459                 false,
 460                 &IntegerSchema::new("File size. This is used to verify that the server got all data.")
 461                     .minimum(1)
 462                     .schema()
 463             ),
 464             ("csum", false, &StringSchema::new("Digest list checksum.").schema()),
 465         ]),
 466     )
 467 );
 468
 469 fn close_dynamic_index (
 470     param: Value,
 471     _info: &ApiMethod,
 472     rpcenv: &mut dyn RpcEnvironment,
 473 ) -> Result<Value, Error> {
 474
 475     let wid = tools::required_integer_param(&param, "wid")? as usize;
 476     let chunk_count = tools::required_integer_param(&param, "chunk-count")? as u64;
 477     let size = tools::required_integer_param(&param, "size")? as u64;
 478     let csum_str = tools::required_string_param(&param, "csum")?;
 479     let csum = proxmox::tools::hex_to_digest(csum_str)?;
 480
 481     let env: &BackupEnvironment = rpcenv.as_ref();
 482
 483     env.dynamic_writer_close(wid, chunk_count, size, csum)?;
 484
 485     env.log(format!("sucessfully closed dynamic index {}", wid));
 486
 487     Ok(Value::Null)
 488 }
 489
 490 #[sortable]
 491 pub const API_METHOD_CLOSE_FIXED_INDEX: ApiMethod = ApiMethod::new(
 492     &ApiHandler::Sync(&close_fixed_index),
 493     &ObjectSchema::new(
 494         "Close fixed index writer.",
 495         &sorted!([
 496             (
 497                 "wid",
 498                 false,
 499                 &IntegerSchema::new("Fixed writer ID.")
 500                     .minimum(1)
 501                     .maximum(256)
 502                     .schema()
 503             ),
 504             (
 505                 "chunk-count",
 506                 false,
 507                 &IntegerSchema::new("Chunk count. This is used to verify that the server got all chunks.")
 508                     .minimum(1)
 509                     .schema()
 510             ),
 511             (
 512                 "size",
 513                 false,
 514                 &IntegerSchema::new("File size. This is used to verify that the server got all data.")
 515                     .minimum(1)
 516                     .schema()
 517             ),
 518             ("csum", false, &StringSchema::new("Digest list checksum.").schema()),
 519         ]),
 520     )
 521 );
 522
 523 fn close_fixed_index (
 524     param: Value,
 525     _info: &ApiMethod,
 526     rpcenv: &mut dyn RpcEnvironment,
 527 ) -> Result<Value, Error> {
 528
 529     let wid = tools::required_integer_param(&param, "wid")? as usize;
 530     let chunk_count = tools::required_integer_param(&param, "chunk-count")? as u64;
 531     let size = tools::required_integer_param(&param, "size")? as u64;
 532     let csum_str = tools::required_string_param(&param, "csum")?;
 533     let csum = proxmox::tools::hex_to_digest(csum_str)?;
 534
 535     let env: &BackupEnvironment = rpcenv.as_ref();
 536
 537     env.fixed_writer_close(wid, chunk_count, size, csum)?;
 538
 539     env.log(format!("sucessfully closed fixed index {}", wid));
 540
 541     Ok(Value::Null)
 542 }
 543
 544 fn finish_backup (
 545     _param: Value,
 546     _info: &ApiMethod,
 547     rpcenv: &mut dyn RpcEnvironment,
 548 ) -> Result<Value, Error> {
 549
 550     let env: &BackupEnvironment = rpcenv.as_ref();
 551
 552     env.finish_backup()?;
 553     env.log("sucessfully finished backup");
 554
 555     Ok(Value::Null)
 556 }
 557
 558 #[sortable]
 559 pub const API_METHOD_DYNAMIC_CHUNK_INDEX: ApiMethod = ApiMethod::new(
 560     &ApiHandler::AsyncHttp(&dynamic_chunk_index),
 561     &ObjectSchema::new(
 562         r###"
 563 Download the dynamic chunk index from the previous backup.
 564 Simply returns an empty list if this is the first backup.
 565 "### ,
 566         &sorted!([
 567             ("archive-name", false, &crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA)
 568         ]),
 569     )
 570 );
 571
 572 fn dynamic_chunk_index(
 573     _parts: Parts,
 574     _req_body: Body,
 575     param: Value,
 576     _info: &ApiMethod,
 577     rpcenv: Box<dyn RpcEnvironment>,
 578 ) -> ApiResponseFuture {
 579
 580     async move {
 581         let env: &BackupEnvironment = rpcenv.as_ref();
 582
 583         let archive_name = tools::required_string_param(&param, "archive-name")?.to_owned();
 584
 585         if !archive_name.ends_with(".didx") {
 586             bail!("wrong archive extension: '{}'", archive_name);
 587         }
 588
 589         let empty_response = {
 590             Response::builder()
 591                 .status(StatusCode::OK)
 592                 .body(Body::empty())?
 593         };
 594
 595         let last_backup = match &env.last_backup {
 596             Some(info) => info,
 597             None => return Ok(empty_response),
 598         };
 599
 600         let mut path = last_backup.backup_dir.relative_path();
 601         path.push(&archive_name);
 602
 603         let index = match env.datastore.open_dynamic_reader(path) {
 604             Ok(index) => index,
 605             Err(_) => {
 606                 env.log(format!("there is no last backup for archive '{}'", archive_name));
 607                 return Ok(empty_response);
 608             }
 609         };
 610
 611         env.log(format!("download last backup index for archive '{}'", archive_name));
 612
 613         let count = index.index_count();
 614         for pos in 0..count {
 615             let (start, end, digest) = index.chunk_info(pos)?;
 616             let size = (end - start) as u32;
 617             env.register_chunk(digest, size)?;
 618         }
 619
 620         let reader = DigestListEncoder::new(Box::new(index));
 621
 622         let stream = WrappedReaderStream::new(reader);
 623
 624         // fixme: set size, content type?
 625         let response = http::Response::builder()
 626             .status(200)
 627             .body(Body::wrap_stream(stream))?;
 628
 629         Ok(response)
 630     }.boxed()
 631 }
 632
 633 #[sortable]
 634 pub const API_METHOD_FIXED_CHUNK_INDEX: ApiMethod = ApiMethod::new(
 635     &ApiHandler::AsyncHttp(&fixed_chunk_index),
 636     &ObjectSchema::new(
 637         r###"
 638 Download the fixed chunk index from the previous backup.
 639 Simply returns an empty list if this is the first backup.
 640 "### ,
 641         &sorted!([
 642             ("archive-name", false, &crate::api2::types::BACKUP_ARCHIVE_NAME_SCHEMA)
 643         ]),
 644     )
 645 );
 646
 647 fn fixed_chunk_index(
 648     _parts: Parts,
 649     _req_body: Body,
 650     param: Value,
 651     _info: &ApiMethod,
 652     rpcenv: Box<dyn RpcEnvironment>,
 653 ) -> ApiResponseFuture {
 654
 655     async move {
 656         let env: &BackupEnvironment = rpcenv.as_ref();
 657
 658         let archive_name = tools::required_string_param(&param, "archive-name")?.to_owned();
 659
 660         if !archive_name.ends_with(".fidx") {
 661             bail!("wrong archive extension: '{}'", archive_name);
 662         }
 663
 664         let empty_response = {
 665             Response::builder()
 666                 .status(StatusCode::OK)
 667                 .body(Body::empty())?
 668         };
 669
 670         let last_backup = match &env.last_backup {
 671             Some(info) => info,
 672             None => return Ok(empty_response),
 673         };
 674
 675         let mut path = last_backup.backup_dir.relative_path();
 676         path.push(&archive_name);
 677
 678         let index = match env.datastore.open_fixed_reader(path) {
 679             Ok(index) => index,
 680             Err(_) => {
 681                 env.log(format!("there is no last backup for archive '{}'", archive_name));
 682                 return Ok(empty_response);
 683             }
 684         };
 685
 686         env.log(format!("download last backup index for archive '{}'", archive_name));
 687
 688         let count = index.index_count();
 689         let image_size = index.index_bytes();
 690         for pos in 0..count {
 691             let digest = index.index_digest(pos).unwrap();
 692             // Note: last chunk can be smaller
 693             let start = (pos*index.chunk_size) as u64;
 694             let mut end = start + index.chunk_size as u64;
 695             if end > image_size { end = image_size; }
 696             let size = (end - start) as u32;
 697             env.register_chunk(*digest, size)?;
 698         }
 699
 700         let reader = DigestListEncoder::new(Box::new(index));
 701
 702         let stream = WrappedReaderStream::new(reader);
 703
 704         // fixme: set size, content type?
 705         let response = http::Response::builder()
 706             .status(200)
 707             .body(Body::wrap_stream(stream))?;
 708
 709         Ok(response)
 710     }.boxed()
 711 }