deb: retrieve .deb artifacts

sbuild options: unshare, build directory

context: retrieve files

src/context/api.rs

@@ -18,6 +18,8 @@ pub trait CommandRunner {
 
 pub trait ContextDriver {
     fn ensure_available(&self, src: &Path, dest_root: &str) -> io::Result<PathBuf>;
+    fn retrieve_path(&self, src: &Path, dest: &Path) -> io::Result<()>;
+    fn list_files(&self, path: &Path) -> io::Result<Vec<PathBuf>>;
     fn create_runner(&self, program: String) -> Box<dyn CommandRunner>;
     fn prepare_work_dir(&self) -> io::Result<String>;
 }
@@ -60,6 +62,19 @@ impl Context {
         self.driver().prepare_work_dir()
     }
 
+    /// Retrieve a file or directory from the context to the local filesystem.
+    ///
+    /// The `src` path is on the context, `dest` is on the local machine.
+    /// If `src` is a directory, it is copied recursively.
+    pub fn retrieve_path(&self, src: &Path, dest: &Path) -> io::Result<()> {
+        self.driver().retrieve_path(src, dest)
+    }
+
+    /// List files in a directory on the context.
+    pub fn list_files(&self, path: &Path) -> io::Result<Vec<PathBuf>> {
+        self.driver().list_files(path)
+    }
+
     fn driver(&self) -> Box<dyn ContextDriver> {
         match self {
             Context::Local => Box::new(LocalDriver),

src/context/local.rs

@@ -21,7 +21,21 @@ impl ContextDriver for LocalDriver {
     }
 
     fn prepare_work_dir(&self) -> io::Result<String> {
-        Ok(".".to_string())
+        // TODO: Fix that, we should not always use '..' as work directory locally
+        Ok("..".to_string())
+    }
+
+    fn retrieve_path(&self, _src: &Path, _dest: &Path) -> io::Result<()> {
+        Ok(())
+    }
+
+    fn list_files(&self, path: &Path) -> io::Result<Vec<PathBuf>> {
+        let mut entries = Vec::new();
+        for entry in std::fs::read_dir(path)? {
+            let entry = entry?;
+            entries.push(entry.path());
+        }
+        Ok(entries)
     }
 }
 

src/context/ssh.rs

@@ -77,6 +77,30 @@ impl ContextDriver for SshDriver {
         })
     }
 
+    fn retrieve_path(&self, src: &Path, dest: &Path) -> io::Result<()> {
+        let sess = connect_ssh(&self.host, self.user.as_deref(), self.port)?;
+        let sftp = sess.sftp().map_err(io::Error::other)?;
+
+        debug!("Downloading remote {:?} to {:?}", src, dest);
+        Self::download_recursive(&sftp, src, dest)
+    }
+
+    fn list_files(&self, path: &Path) -> io::Result<Vec<PathBuf>> {
+        let sess = connect_ssh(&self.host, self.user.as_deref(), self.port)?;
+        let sftp = sess.sftp().map_err(io::Error::other)?;
+
+        let mut files = Vec::new();
+        let entries = sftp.readdir(path).map_err(io::Error::other)?;
+        for (p, _) in entries {
+            let file_name = p.file_name().unwrap();
+            if file_name == "." || file_name == ".." {
+                continue;
+            }
+            files.push(p);
+        }
+        Ok(files)
+    }
+
     fn prepare_work_dir(&self) -> io::Result<String> {
         let sess = connect_ssh(&self.host, self.user.as_deref(), self.port)?;
         let mut channel = sess.channel_session().map_err(io::Error::other)?;
@@ -118,6 +142,30 @@ impl SshDriver {
         }
         Ok(())
     }
+
+    fn download_recursive(sftp: &ssh2::Sftp, src: &Path, dest: &Path) -> io::Result<()> {
+        let stat = sftp
+            .stat(src)
+            .map_err(|e| io::Error::other(format!("Remote stat failed for {:?}: {}", src, e)))?;
+
+        if stat.is_dir() {
+            fs::create_dir_all(dest)?;
+            let entries = sftp.readdir(src).map_err(io::Error::other)?;
+            for (path, _) in entries {
+                let file_name = path.file_name().unwrap();
+                if file_name == "." || file_name == ".." {
+                    continue;
+                }
+                let new_dest = dest.join(file_name);
+                Self::download_recursive(sftp, &path, &new_dest)?;
+            }
+        } else {
+            let mut remote_file = sftp.open(src).map_err(io::Error::other)?;
+            let mut local_file = fs::File::create(dest)?;
+            io::copy(&mut remote_file, &mut local_file)?;
+        }
+        Ok(())
+    }
 }
 
 pub struct SshRunner {