Source code for yardstick.ssh

# Copyright 2013: Mirantis Inc.
# 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.

# yardstick comment: this is a modified copy of rally/rally/common/sshutils.py

"""High level ssh library.

Usage examples:

Execute command and get output:

    ssh = sshclient.SSH("root", "example.com", port=33)
    status, stdout, stderr = ssh.execute("ps ax")
    if status:
        raise Exception("Command failed with non-zero status.")
    print stdout.splitlines()

Execute command with huge output:

    class PseudoFile(object):
        def write(chunk):
            if "error" in chunk:
                email_admin(chunk)

    ssh = sshclient.SSH("root", "example.com")
    ssh.run("tail -f /var/log/syslog", stdout=PseudoFile(), timeout=False)

Execute local script on remote side:

    ssh = sshclient.SSH("user", "example.com")
    status, out, err = ssh.execute("/bin/sh -s arg1 arg2",
                                   stdin=open("~/myscript.sh", "r"))

Upload file:

    ssh = sshclient.SSH("user", "example.com")
    ssh.run("cat > ~/upload/file.gz", stdin=open("/store/file.gz", "rb"))

Eventlet:

    eventlet.monkey_patch(select=True, time=True)
    or
    eventlet.monkey_patch()
    or
    sshclient = eventlet.import_patched("opentstack.common.sshclient")

"""

import select
import socket
import time

import paramiko
from scp import SCPClient
import six
import logging

LOG = logging.getLogger(__name__)


[docs]class SSHError(Exception): pass
[docs]class SSHTimeout(SSHError): pass
[docs]class SSH(object): """Represent ssh connection.""" def __init__(self, user, host, port=22, pkey=None, key_filename=None, password=None): """Initialize SSH client. :param user: ssh username :param host: hostname or ip address of remote ssh server :param port: remote ssh port :param pkey: RSA or DSS private key string or file object :param key_filename: private key filename :param password: password """ self.user = user self.host = host self.port = port self.pkey = self._get_pkey(pkey) if pkey else None self.password = password self.key_filename = key_filename self._client = False def _get_pkey(self, key): if isinstance(key, six.string_types): key = six.moves.StringIO(key) errors = [] for key_class in (paramiko.rsakey.RSAKey, paramiko.dsskey.DSSKey): try: return key_class.from_private_key(key) except paramiko.SSHException as e: errors.append(e) raise SSHError("Invalid pkey: %s" % (errors)) def _get_client(self): if self._client: return self._client try: self._client = paramiko.SSHClient() self._client.set_missing_host_key_policy(paramiko.AutoAddPolicy()) self._client.connect(self.host, username=self.user, port=self.port, pkey=self.pkey, key_filename=self.key_filename, password=self.password, timeout=1) return self._client except Exception as e: message = ("Exception %(exception_type)s was raised " "during connect. Exception value is: %(exception)r") self._client = False raise SSHError(message % {"exception": e, "exception_type": type(e)})
[docs] def close(self): self._client.close() self._client = False
[docs] def run(self, cmd, stdin=None, stdout=None, stderr=None, raise_on_error=True, timeout=3600): """Execute specified command on the server. :param cmd: Command to be executed. :param stdin: Open file or string to pass to stdin. :param stdout: Open file to connect to stdout. :param stderr: Open file to connect to stderr. :param raise_on_error: If False then exit code will be return. If True then exception will be raized if non-zero code. :param timeout: Timeout in seconds for command execution. Default 1 hour. No timeout if set to 0. """ client = self._get_client() if isinstance(stdin, six.string_types): stdin = six.moves.StringIO(stdin) return self._run(client, cmd, stdin=stdin, stdout=stdout, stderr=stderr, raise_on_error=raise_on_error, timeout=timeout)
def _run(self, client, cmd, stdin=None, stdout=None, stderr=None, raise_on_error=True, timeout=3600): transport = client.get_transport() session = transport.open_session() session.exec_command(cmd) start_time = time.time() data_to_send = "" stderr_data = None # If we have data to be sent to stdin then `select' should also # check for stdin availability. if stdin and not stdin.closed: writes = [session] else: writes = [] while True: # Block until data can be read/write. r, w, e = select.select([session], writes, [session], 1) if session.recv_ready(): data = session.recv(4096) LOG.debug("stdout: %r" % data) if stdout is not None: stdout.write(data) continue if session.recv_stderr_ready(): stderr_data = session.recv_stderr(4096) LOG.debug("stderr: %r" % stderr_data) if stderr is not None: stderr.write(stderr_data) continue if session.send_ready(): if stdin is not None and not stdin.closed: if not data_to_send: data_to_send = stdin.read(4096) if not data_to_send: stdin.close() session.shutdown_write() writes = [] continue sent_bytes = session.send(data_to_send) # LOG.debug("sent: %s" % data_to_send[:sent_bytes]) data_to_send = data_to_send[sent_bytes:] if session.exit_status_ready(): break if timeout and (time.time() - timeout) > start_time: args = {"cmd": cmd, "host": self.host} raise SSHTimeout("Timeout executing command " "'%(cmd)s' on host %(host)s" % args) if e: raise SSHError("Socket error.") exit_status = session.recv_exit_status() if 0 != exit_status and raise_on_error: fmt = "Command '%(cmd)s' failed with exit_status %(status)d." details = fmt % {"cmd": cmd, "status": exit_status} if stderr_data: details += " Last stderr data: '%s'." % stderr_data raise SSHError(details) return exit_status
[docs] def execute(self, cmd, stdin=None, timeout=3600): """Execute the specified command on the server. :param cmd: Command to be executed. :param stdin: Open file to be sent on process stdin. :param timeout: Timeout for execution of the command. :returns: tuple (exit_status, stdout, stderr) """ stdout = six.moves.StringIO() stderr = six.moves.StringIO() exit_status = self.run(cmd, stderr=stderr, stdout=stdout, stdin=stdin, timeout=timeout, raise_on_error=False) stdout.seek(0) stderr.seek(0) return (exit_status, stdout.read(), stderr.read())
[docs] def wait(self, timeout=120, interval=1): """Wait for the host will be available via ssh.""" start_time = time.time() while True: try: return self.execute("uname") except (socket.error, SSHError) as e: LOG.debug("Ssh is still unavailable: %r" % e) time.sleep(interval) if time.time() > (start_time + timeout): raise SSHTimeout("Timeout waiting for '%s'" % self.host)
[docs] def put(self, files, remote_path=b'.', recursive=False): client = self._get_client() with SCPClient(client.get_transport()) as scp: scp.put(files, remote_path, recursive)