opendal/services/sftp/
backend.rs

1// Licensed to the Apache Software Foundation (ASF) under one
2// or more contributor license agreements.  See the NOTICE file
3// distributed with this work for additional information
4// regarding copyright ownership.  The ASF licenses this file
5// to you under the Apache License, Version 2.0 (the
6// "License"); you may not use this file except in compliance
7// with the License.  You may obtain a copy of the License at
8//
9//   http://www.apache.org/licenses/LICENSE-2.0
10//
11// Unless required by applicable law or agreed to in writing,
12// software distributed under the License is distributed on an
13// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
14// KIND, either express or implied.  See the License for the
15// specific language governing permissions and limitations
16// under the License.
17
18use std::fmt::Debug;
19use std::fmt::Formatter;
20use std::io::SeekFrom;
21use std::path::Path;
22use std::path::PathBuf;
23use std::sync::Arc;
24
25use log::debug;
26use openssh::KnownHosts;
27use tokio::io::AsyncSeekExt;
28use tokio::sync::OnceCell;
29
30use super::core::SftpCore;
31use super::delete::SftpDeleter;
32use super::error::is_not_found;
33use super::error::is_sftp_protocol_error;
34use super::error::parse_sftp_error;
35use super::lister::SftpLister;
36use super::reader::SftpReader;
37use super::writer::SftpWriter;
38use crate::raw::*;
39use crate::services::SftpConfig;
40use crate::*;
41
42impl Configurator for SftpConfig {
43    type Builder = SftpBuilder;
44    fn into_builder(self) -> Self::Builder {
45        SftpBuilder { config: self }
46    }
47}
48
49/// SFTP services support. (only works on unix)
50///
51/// If you are interested in working on windows, please refer to [this](https://github.com/apache/opendal/issues/2963) issue.
52/// Welcome to leave your comments or make contributions.
53///
54/// Warning: Maximum number of file holdings is depending on the remote system configuration.
55///
56/// For example, the default value is 255 in macOS, and 1024 in linux. If you want to open
57/// lots of files, you should pay attention to close the file after using it.
58#[doc = include_str!("docs.md")]
59#[derive(Default)]
60pub struct SftpBuilder {
61    config: SftpConfig,
62}
63
64impl Debug for SftpBuilder {
65    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
66        f.debug_struct("SftpBuilder")
67            .field("config", &self.config)
68            .finish()
69    }
70}
71
72impl SftpBuilder {
73    /// set endpoint for sftp backend.
74    /// The format is same as `openssh`, using either `[user@]hostname` or `ssh://[user@]hostname[:port]`. A username or port that is specified in the endpoint overrides the one set in the builder (but does not change the builder).
75    pub fn endpoint(mut self, endpoint: &str) -> Self {
76        self.config.endpoint = if endpoint.is_empty() {
77            None
78        } else {
79            Some(endpoint.to_string())
80        };
81
82        self
83    }
84
85    /// set root path for sftp backend.
86    /// It uses the default directory set by the remote `sftp-server` as default.
87    pub fn root(mut self, root: &str) -> Self {
88        self.config.root = if root.is_empty() {
89            None
90        } else {
91            Some(root.to_string())
92        };
93
94        self
95    }
96
97    /// set user for sftp backend.
98    pub fn user(mut self, user: &str) -> Self {
99        self.config.user = if user.is_empty() {
100            None
101        } else {
102            Some(user.to_string())
103        };
104
105        self
106    }
107
108    /// set key path for sftp backend.
109    pub fn key(mut self, key: &str) -> Self {
110        self.config.key = if key.is_empty() {
111            None
112        } else {
113            Some(key.to_string())
114        };
115
116        self
117    }
118
119    /// set known_hosts strategy for sftp backend.
120    /// available values:
121    /// - Strict (default)
122    /// - Accept
123    /// - Add
124    pub fn known_hosts_strategy(mut self, strategy: &str) -> Self {
125        self.config.known_hosts_strategy = if strategy.is_empty() {
126            None
127        } else {
128            Some(strategy.to_string())
129        };
130
131        self
132    }
133
134    /// set enable_copy for sftp backend.
135    /// It requires the server supports copy-file extension.
136    pub fn enable_copy(mut self, enable_copy: bool) -> Self {
137        self.config.enable_copy = enable_copy;
138
139        self
140    }
141}
142
143impl Builder for SftpBuilder {
144    const SCHEME: Scheme = Scheme::Sftp;
145    type Config = SftpConfig;
146
147    fn build(self) -> Result<impl Access> {
148        debug!("sftp backend build started: {:?}", &self);
149        let endpoint = match self.config.endpoint.clone() {
150            Some(v) => v,
151            None => return Err(Error::new(ErrorKind::ConfigInvalid, "endpoint is empty")),
152        };
153
154        let user = self.config.user.clone();
155
156        let root = self
157            .config
158            .root
159            .clone()
160            .map(|r| normalize_root(r.as_str()))
161            .unwrap_or_default();
162
163        let known_hosts_strategy = match &self.config.known_hosts_strategy {
164            Some(v) => {
165                let v = v.to_lowercase();
166                if v == "strict" {
167                    KnownHosts::Strict
168                } else if v == "accept" {
169                    KnownHosts::Accept
170                } else if v == "add" {
171                    KnownHosts::Add
172                } else {
173                    return Err(Error::new(
174                        ErrorKind::ConfigInvalid,
175                        format!("unknown known_hosts strategy: {v}").as_str(),
176                    ));
177                }
178            }
179            None => KnownHosts::Strict,
180        };
181
182        let info = AccessorInfo::default();
183        info.set_root(root.as_str())
184            .set_scheme(Scheme::Sftp)
185            .set_native_capability(Capability {
186                stat: true,
187
188                read: true,
189
190                write: true,
191                write_can_multi: true,
192
193                create_dir: true,
194                delete: true,
195
196                list: true,
197                list_with_limit: true,
198
199                copy: self.config.enable_copy,
200                rename: true,
201
202                shared: true,
203
204                ..Default::default()
205            });
206
207        let accessor_info = Arc::new(info);
208        let core = Arc::new(SftpCore {
209            info: accessor_info,
210            endpoint,
211            root,
212            user,
213            key: self.config.key.clone(),
214            known_hosts_strategy,
215
216            client: OnceCell::new(),
217        });
218
219        debug!("sftp backend finished: {:?}", &self);
220        Ok(SftpBackend { core })
221    }
222}
223
224/// Backend is used to serve `Accessor` support for sftp.
225#[derive(Clone)]
226pub struct SftpBackend {
227    pub core: Arc<SftpCore>,
228}
229
230impl Debug for SftpBackend {
231    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
232        f.debug_struct("SftpBackend")
233            .field("core", &self.core)
234            .finish()
235    }
236}
237
238impl Access for SftpBackend {
239    type Reader = SftpReader;
240    type Writer = SftpWriter;
241    type Lister = Option<SftpLister>;
242    type Deleter = oio::OneShotDeleter<SftpDeleter>;
243
244    fn info(&self) -> Arc<AccessorInfo> {
245        self.core.info.clone()
246    }
247
248    async fn create_dir(&self, path: &str, _: OpCreateDir) -> Result<RpCreateDir> {
249        let client = self.core.connect().await?;
250        let mut fs = client.fs();
251        fs.set_cwd(&self.core.root);
252
253        let paths = Path::new(&path).components();
254        let mut current = PathBuf::from(&self.core.root);
255        for p in paths {
256            current = current.join(p);
257            let res = fs.create_dir(p).await;
258
259            if let Err(e) = res {
260                // ignore error if dir already exists
261                if !is_sftp_protocol_error(&e) {
262                    return Err(parse_sftp_error(e));
263                }
264            }
265            fs.set_cwd(&current);
266        }
267
268        Ok(RpCreateDir::default())
269    }
270
271    async fn stat(&self, path: &str, _: OpStat) -> Result<RpStat> {
272        let client = self.core.connect().await?;
273        let mut fs = client.fs();
274        fs.set_cwd(&self.core.root);
275
276        let meta: Metadata = fs.metadata(path).await.map_err(parse_sftp_error)?.into();
277
278        Ok(RpStat::new(meta))
279    }
280
281    async fn read(&self, path: &str, args: OpRead) -> Result<(RpRead, Self::Reader)> {
282        let client = self.core.connect().await?;
283
284        let mut fs = client.fs();
285        fs.set_cwd(&self.core.root);
286
287        let path = fs.canonicalize(path).await.map_err(parse_sftp_error)?;
288
289        let mut f = client
290            .open(path.as_path())
291            .await
292            .map_err(parse_sftp_error)?;
293
294        if args.range().offset() != 0 {
295            f.seek(SeekFrom::Start(args.range().offset()))
296                .await
297                .map_err(new_std_io_error)?;
298        }
299
300        Ok((
301            RpRead::default(),
302            SftpReader::new(client, f, args.range().size()),
303        ))
304    }
305
306    async fn write(&self, path: &str, op: OpWrite) -> Result<(RpWrite, Self::Writer)> {
307        if let Some((dir, _)) = path.rsplit_once('/') {
308            self.create_dir(dir, OpCreateDir::default()).await?;
309        }
310
311        let client = self.core.connect().await?;
312
313        let mut fs = client.fs();
314        fs.set_cwd(&self.core.root);
315        let path = fs.canonicalize(path).await.map_err(parse_sftp_error)?;
316
317        let mut option = client.options();
318        option.create(true);
319        if op.append() {
320            option.append(true);
321        } else {
322            option.write(true).truncate(true);
323        }
324
325        let file = option.open(path).await.map_err(parse_sftp_error)?;
326
327        Ok((RpWrite::new(), SftpWriter::new(file)))
328    }
329
330    async fn delete(&self) -> Result<(RpDelete, Self::Deleter)> {
331        Ok((
332            RpDelete::default(),
333            oio::OneShotDeleter::new(SftpDeleter::new(self.core.clone())),
334        ))
335    }
336
337    async fn list(&self, path: &str, _: OpList) -> Result<(RpList, Self::Lister)> {
338        let client = self.core.connect().await?;
339        let mut fs = client.fs();
340        fs.set_cwd(&self.core.root);
341
342        let file_path = format!("./{path}");
343
344        let dir = match fs.open_dir(&file_path).await {
345            Ok(dir) => dir,
346            Err(e) => {
347                if is_not_found(&e) {
348                    return Ok((RpList::default(), None));
349                } else {
350                    return Err(parse_sftp_error(e));
351                }
352            }
353        }
354        .read_dir();
355
356        Ok((
357            RpList::default(),
358            Some(SftpLister::new(dir, path.to_owned())),
359        ))
360    }
361
362    async fn copy(&self, from: &str, to: &str, _: OpCopy) -> Result<RpCopy> {
363        let client = self.core.connect().await?;
364
365        let mut fs = client.fs();
366        fs.set_cwd(&self.core.root);
367
368        if let Some((dir, _)) = to.rsplit_once('/') {
369            self.create_dir(dir, OpCreateDir::default()).await?;
370        }
371
372        let src = fs.canonicalize(from).await.map_err(parse_sftp_error)?;
373        let dst = fs.canonicalize(to).await.map_err(parse_sftp_error)?;
374        let mut src_file = client.open(&src).await.map_err(parse_sftp_error)?;
375        let mut dst_file = client.create(dst).await.map_err(parse_sftp_error)?;
376
377        src_file
378            .copy_all_to(&mut dst_file)
379            .await
380            .map_err(parse_sftp_error)?;
381
382        Ok(RpCopy::default())
383    }
384
385    async fn rename(&self, from: &str, to: &str, _: OpRename) -> Result<RpRename> {
386        let client = self.core.connect().await?;
387
388        let mut fs = client.fs();
389        fs.set_cwd(&self.core.root);
390
391        if let Some((dir, _)) = to.rsplit_once('/') {
392            self.create_dir(dir, OpCreateDir::default()).await?;
393        }
394        fs.rename(from, to).await.map_err(parse_sftp_error)?;
395
396        Ok(RpRename::default())
397    }
398}
opendal/services/sftp/backend.rs

opendal/services/sftp/
backend.rs
