# Copyright 2015 The Bazel Authors. All rights reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. # You may obtain a copy of the License at # # http://www.apache.org/licenses/LICENSE-2.0 # # Unless required by applicable law or agreed to in writing, software # distributed under the License is distributed on an "AS IS" BASIS, # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. # See the License for the specific language governing permissions and # limitations under the License. """Archive manipulation library for the Docker rules.""" import os import tarfile # Use a deterministic mtime that doesn't confuse other programs. # See: https://github.com/bazelbuild/bazel/issues/1299 PORTABLE_MTIME = 946684800 # 2000-01-01 00:00:00.000 UTC DEFAULT_MTIME = 0 # The posix beginning of time class TarFileWriter(object): """A wrapper to write tar files.""" class Error(Exception): pass def __init__(self, name, root_directory='./', preserve_tar_mtimes=False): """TarFileWriter wraps tarfile.open(). Args: name: the tar file name. root_directory: virtual root to prepend to elements in the archive. preserve_tar_mtimes: if true, keep file mtimes from input tar file. """ mode = 'w:' self.name = name self.root_directory = root_directory.rstrip('/') self.preserve_mtime = preserve_tar_mtimes self.fileobj = None self.tar = tarfile.open(name=name, mode=mode, fileobj=self.fileobj) self.members = set([]) self.directories = set([]) def __enter__(self): return self def __exit__(self, t, v, traceback): self.close() def add_dir(self, name, path, uid=0, gid=0, uname='', gname='', mtime=None, mode=None, depth=100): """Recursively add a directory. Args: name: the destination path of the directory to add. path: the path of the directory to add. uid: owner user identifier. gid: owner group identifier. uname: owner user names. gname: owner group names. mtime: modification time to put in the archive. mode: unix permission mode of the file, default 0644 (0755). depth: maximum depth to recurse in to avoid infinite loops with cyclic mounts. Raises: TarFileWriter.Error: when the recursion depth has exceeded the `depth` argument. """ if not (name == self.root_directory or name.startswith('/') or name.startswith(self.root_directory + '/')): name = os.path.join(self.root_directory, name) if mtime is None: mtime = DEFAULT_MTIME if os.path.isdir(path): # Remove trailing '/' (index -1 => last character) if name[-1] == '/': name = name[:-1] # Add the x bit to directories to prevent non-traversable directories. # The x bit is set only to if the read bit is set. dirmode = (mode | ((0o444 & mode) >> 2)) if mode else mode self.add_file( name + '/', tarfile.DIRTYPE, uid=uid, gid=gid, uname=uname, gname=gname, mtime=mtime, mode=dirmode) if depth <= 0: raise self.Error('Recursion depth exceeded, probably in ' 'an infinite directory loop.') # Iterate over the sorted list of file so we get a deterministic result. filelist = os.listdir(path) filelist.sort() for f in filelist: new_name = os.path.join(name, f) new_path = os.path.join(path, f) self.add_dir(new_name, new_path, uid, gid, uname, gname, mtime, mode, depth - 1) else: self.add_file(name, tarfile.REGTYPE, file_content=path, uid=uid, gid=gid, uname=uname, gname=gname, mtime=mtime, mode=mode) def _addfile(self, info, fileobj=None): """Add a file in the tar file if there is no conflict.""" if not info.name.endswith('/') and info.type == tarfile.DIRTYPE: # Enforce the ending / for directories so we correctly deduplicate. info.name += '/' if info.name not in self.members: self.tar.addfile(info, fileobj) self.members.add(info.name) elif info.type != tarfile.DIRTYPE: print(('Duplicate file in archive: %s, ' 'picking first occurrence' % info.name)) def add_file(self, name, kind=tarfile.REGTYPE, link=None, file_content=None, uid=0, gid=0, uname='', gname='', mtime=None, mode=None): """Add a file to the current tar. Args: name: the name of the file to add. kind: the type of the file to add, see tarfile.*TYPE. link: if the file is a link, the destination of the link. file_content: file to read the content from. Provide either this one or `content` to specifies a content for the file. uid: owner user identifier. gid: owner group identifier. uname: owner user names. gname: owner group names. mtime: modification time to put in the archive. mode: unix permission mode of the file, default 0644 (0755). """ if file_content and os.path.isdir(file_content): # Recurse into directory self.add_dir(name, file_content, uid, gid, uname, gname, mtime, mode) return if not (name == self.root_directory or name.startswith('/') or name.startswith(self.root_directory + '/')): name = os.path.join(self.root_directory, name) if kind == tarfile.DIRTYPE: name = name.rstrip('/') if name in self.directories: return if mtime is None: mtime = DEFAULT_MTIME components = name.rsplit('/', 1) if len(components) > 1: d = components[0] self.add_file(d, tarfile.DIRTYPE, uid=uid, gid=gid, uname=uname, gname=gname, mtime=mtime, mode=0o755) tarinfo = tarfile.TarInfo(name) tarinfo.mtime = mtime tarinfo.uid = uid tarinfo.gid = gid tarinfo.uname = uname tarinfo.gname = gname tarinfo.type = kind if mode is None: tarinfo.mode = 0o644 if kind == tarfile.REGTYPE else 0o755 else: tarinfo.mode = mode if link: tarinfo.linkname = link if file_content: with open(file_content, 'rb') as f: tarinfo.size = os.fstat(f.fileno()).st_size self._addfile(tarinfo, f) else: if kind == tarfile.DIRTYPE: self.directories.add(name) self._addfile(tarinfo) def close(self): """Close the output tar file. This class should not be used anymore after calling that method. Raises: TarFileWriter.Error: if an error happens when compressing the output file. """ self.tar.close() # Close the gzip file object if necessary. if self.fileobj: self.fileobj.close()