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Diffstat (limited to 'pygerrit/ssh.py')
| -rw-r--r-- | pygerrit/ssh.py | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/pygerrit/ssh.py b/pygerrit/ssh.py new file mode 100644 index 0000000..2933ddf --- /dev/null +++ b/pygerrit/ssh.py @@ -0,0 +1,178 @@ +# The MIT License +# +# Copyright 2012 Sony Mobile Communications. All rights reserved. +# +# Permission is hereby granted, free of charge, to any person obtaining a copy +# of this software and associated documentation files (the "Software"), to deal +# in the Software without restriction, including without limitation the rights +# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +# copies of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be included in +# all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +# THE SOFTWARE. + +""" Gerrit SSH Client. """ + +from os.path import abspath, expanduser, isfile +import re +import socket +from threading import Event, Lock + +from .error import GerritError + +from paramiko import SSHClient, SSHConfig +from paramiko.ssh_exception import SSHException + + +def _extract_version(version_string, pattern): + """ Extract the version from `version_string` using `pattern`. + + Return the version as a string, with leading/trailing whitespace + stripped. + + """ + if version_string: + match = pattern.match(version_string.strip()) + if match: + return match.group(1) + return "" + + +class GerritSSHCommandResult(object): + + """ Represents the results of a Gerrit command run over SSH. """ + + def __init__(self, command, stdin, stdout, stderr): + self.command = command + self.stdin = stdin + self.stdout = stdout + self.stderr = stderr + + def __repr__(self): + return "<GerritSSHCommandResult [%s]>" % self.command + + +class GerritSSHClient(SSHClient): + + """ Gerrit SSH Client, wrapping the paramiko SSH Client. """ + + def __init__(self, hostname, username=None, port=None): + """ Initialise and connect to SSH. """ + super(GerritSSHClient, self).__init__() + self.remote_version = None + self.hostname = hostname + self.username = username + self.key_filename = None + self.port = port + self.connected = Event() + self.lock = Lock() + + def _configure(self): + """ Configure the ssh parameters from the config file. """ + configfile = expanduser("~/.ssh/config") + if not isfile(configfile): + raise GerritError("ssh config file '%s' does not exist" % + configfile) + + config = SSHConfig() + config.parse(open(configfile)) + data = config.lookup(self.hostname) + if not data: + raise GerritError("No ssh config for host %s" % self.hostname) + if not 'hostname' in data or not 'port' in data or not 'user' in data: + raise GerritError("Missing configuration data in %s" % configfile) + self.hostname = data['hostname'] + self.username = data['user'] + if 'identityfile' in data: + key_filename = abspath(expanduser(data['identityfile'][0])) + if not isfile(key_filename): + raise GerritError("Identity file '%s' does not exist" % + key_filename) + self.key_filename = key_filename + try: + self.port = int(data['port']) + except ValueError: + raise GerritError("Invalid port: %s" % data['port']) + + def _do_connect(self): + """ Connect to the remote. """ + self.load_system_host_keys() + if self.username is None or self.port is None: + self._configure() + try: + self.connect(hostname=self.hostname, + port=self.port, + username=self.username, + key_filename=self.key_filename) + except socket.error as e: + raise GerritError("Failed to connect to server: %s" % e) + + try: + version_string = self._transport.remote_version + pattern = re.compile(r'^.*GerritCodeReview_([a-z0-9-\.]*) .*$') + self.remote_version = _extract_version(version_string, pattern) + except AttributeError: + self.remote_version = None + + def _connect(self): + """ Connect to the remote if not already connected. """ + if not self.connected.is_set(): + try: + self.lock.acquire() + # Another thread may have connected while we were + # waiting to acquire the lock + if not self.connected.is_set(): + self._do_connect() + self.connected.set() + except GerritError: + raise + finally: + self.lock.release() + + def get_remote_version(self): + """ Return the version of the remote Gerrit server. """ + if self.remote_version is None: + result = self.run_gerrit_command("version") + version_string = result.stdout.read() + pattern = re.compile(r'^gerrit version (.*)$') + self.remote_version = _extract_version(version_string, pattern) + return self.remote_version + + def get_remote_info(self): + """ Return the username, and version of the remote Gerrit server. """ + version = self.get_remote_version() + return (self.username, version) + + def run_gerrit_command(self, command): + """ Run the given command. + + Make sure we're connected to the remote server, and run `command`. + + Return the results as a `GerritSSHCommandResult`. + + Raise `ValueError` if `command` is not a string, or `GerritError` if + command execution fails. + + """ + if not isinstance(command, basestring): + raise ValueError("command must be a string") + gerrit_command = "gerrit " + command + + self._connect() + try: + stdin, stdout, stderr = self.exec_command(gerrit_command, + bufsize=1, + timeout=None, + get_pty=False) + except SSHException as err: + raise GerritError("Command execution error: %s" % err) + return GerritSSHCommandResult(command, stdin, stdout, stderr) |