Commit da7e44ee authored by Michael Hanselmann's avatar Michael Hanselmann
Browse files

Initial import of listrunner



This tool was used and worked on internally for quite a long time. We
decided to include it in Ganeti.

Known issues:
- Code doesn't match rest of Ganeti (e.g. using “print” all over the
  place, hardcoded calls to sys.exit deep in functions)
- Code duplication from Ganeti library (e.g. PingByTcp/netutils.TcpPing,
  GetHosts/utils.ReadFile)
- Using ssh-agent doesn't work with more than one worker (Paramiko keeps
  the socket open and the file descriptor is used from different
  workers)
  - No clear separation between parent and child process in code
- Uses getopt instead of optparse
Signed-off-by: default avatarMichael Hanselmann <hansmi@google.com>
Reviewed-by: default avatarIustin Pop <iustin@google.com>
parent c4f10abb
...@@ -324,7 +324,8 @@ qa_scripts = \ ...@@ -324,7 +324,8 @@ qa_scripts = \
qa/qa_tags.py \ qa/qa_tags.py \
qa/qa_utils.py qa/qa_utils.py
dist_sbin_SCRIPTS = dist_sbin_SCRIPTS = \
tools/ganeti-listrunner
nodist_sbin_SCRIPTS = \ nodist_sbin_SCRIPTS = \
$(PYTHON_BOOTSTRAP) \ $(PYTHON_BOOTSTRAP) \
...@@ -397,6 +398,7 @@ man_MANS = \ ...@@ -397,6 +398,7 @@ man_MANS = \
man/ganeti.7 \ man/ganeti.7 \
man/ganeti-cleaner.8 \ man/ganeti-cleaner.8 \
man/ganeti-confd.8 \ man/ganeti-confd.8 \
man/ganeti-listrunner.8 \
man/ganeti-masterd.8 \ man/ganeti-masterd.8 \
man/ganeti-noded.8 \ man/ganeti-noded.8 \
man/ganeti-os-interface.7 \ man/ganeti-os-interface.7 \
......
ganeti-listrunner(8) Ganeti | Version @GANETI_VERSION@
======================================================
NAME
----
ganeti-listrunner - Run commands in parallel over multiple machines
SYNOPSIS
--------
**ganeti-listrunner** ``-l`` *logdir*
{``-x`` *executable* | ``-c`` *shell-cmd*}
{``-f`` *hostfile* | ``-h`` *hostlist*}
[``-a`` *aux-file*]
[``-b`` *batch-size*]
[``-u`` *username*]
[``-A``]
DESCRIPTION
-----------
**ganeti-listrunner** is a tool to run commands in parallel over multiple
machines. It differs from ``dsh`` or other tools in that it asks for the
password once (if not using ``ssh-agent``) and then reuses the password to
connect to all machines, thus being easily usable even when public key
authentication or Kerberos authentication is not available.
It can run either a command or a script (which gets uploaded first and deleted
after execution) on a list of hosts provided either via a file (one host per
line) or as a comma-separated list on the commandline. The out‐ put (stdout and
stderr are merged) of the remote execution is written to a logfile. One logfile
per host is written.
OPTIONS
-------
The options that can be passed to the program are as follows:
``-l`` *logdir*
The directory under which the logfiles files should be written.
``-x`` *executable*
The executable to copy and run on the target hosts.
``-c`` *shell-cmd*
The shell command to run on the remote hosts.
``-f`` *hostfile*
The file with the target hosts, one hostname per line.
``-h`` *hostlist*
Comma-separated list of target hosts.
``-a`` *aux-file*
A file to copy to the target hosts. Can be given multiple times, in which case
all files will be copied to the temporary directory. The executable or the
shell command will be run from the (temporary) directory where these files
have been copied.
``-b`` *batch-size*
The host list will be split into batches of batch-size which will be processed
in parallel. The default if 15, and should be increased if faster processing
is needed.
``-u`` *username*
Username to connect as instead of the default root username.
``-A``
Use an existing ssh-agent instead of password authentication.
EXIT STATUS
-----------
The exist status of the command will be zero, unless it was aborted in some way
(e.g. ^C).
EXAMPLE
-------
Run a command on a list of hosts::
listrunner -l logdir -c "uname -a" -h host1,host2,host3
Upload a script, some auxiliary files and run the script::
listrunner -l logdir -x runme.sh -a seed.dat -a golden.dat -h host1,host2,host3
SEE ALSO
--------
dsh(1), cssh(1)
#!/usr/bin/python
#
# Copyright (C) 2006, 2007, 2010 Google Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful, but
# WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
# 02110-1301, USA.
"""Run an executable on a list of hosts.
Script to serially run an executable on a list of hosts via ssh
with password auth as root. If the provided log dir does not yet
exist, it will try to create it.
Implementation:
- the main process spawns up to batch_size children, which:
- connects to the remote host via ssh as root
- uploads the executable with a random name to /tmp via sftp
- chmod 500s it
- via ssh: chdirs into the upload directory and runs the script
- deletes it
- writes status messages and all output to one logfile per host
- the main process gathers then the status of the children and
reports the success/failure ratio
- entire script can be aborted with Ctrl-C
Security considerations:
- the root password for the remote hosts is stored in memory for the
runtime of the script
- the executable to be run on the remote host is handled the following way:
- try to create a random directory with permissions 700 on the
remote host, abort furter processing on this host if this failes
- upload the executable with to a random filename in that directory
- set executable permissions to 500
- run the executable
- delete the execuable and the directory on the remote host
"""
# pylint: disable-msg=C0103
# C0103: Invalid name ganeti-listrunner
import errno
import getopt
import getpass
import logging
import os
import random
import select
import socket
import sys
import time
import traceback
import paramiko
REMOTE_PATH_BASE = "/tmp/listrunner"
def LogDirUseable(logdir):
"""Ensure log file directory is available and usable."""
testfile = "%s/test-%s-%s.deleteme" % (logdir, random.random(),
random.random())
try:
os.mkdir(logdir)
except OSError, err:
if err.errno != errno.EEXIST:
raise
try:
logtest = open(testfile, "aw")
logtest.writelines("log file writeability test\n")
logtest.close()
os.unlink(testfile)
return True
except (OSError, IOError):
return False
def ShowHelp(executable):
"""Print short usage information."""
print ("usage: %s -l logdir [-c|-x] value [-b batch_size]"
" [-f hostfile|-h hosts] [-u username]"
" [-p password_file]" % executable)
print """ -l logdir to write logfiles to
-x executable to run on remote host(s)
-c shell command to run on remote host(s)
-f hostlist file (one host per line)
-a optional auxiliary file to upload (can be given multiple times)
-b batch-size, how many hosts to process in parallel [15]
-h comma-separated list of hosts or single hostname
-u username used to connect [root]
-p password used to authenticate"""
def GetTimeStamp(timestamp=None):
"""Return ISO8601 timestamp.
Returns ISO8601 timestamp, optionally expects a time.localtime() tuple
in timestamp, but will use the current time if this argument is not
supplied.
"""
if timestamp is None:
timestamp = time.localtime()
isotime = time.strftime("%Y-%m-%dT%H:%M:%S", timestamp)
return isotime
def PingByTcp(target, port, timeout=10, live_port_needed=False, source=None):
"""Simple ping implementation using TCP connect(2).
Try to do a TCP connect(2) from an optional source IP to the
specified target IP and the specified target port. If the optional
parameter live_port_needed is set to true, requires the remote end
to accept the connection. The timeout is specified in seconds and
defaults to 10 seconds. If the source optional argument is not
passed, the source address selection is left to the kernel,
otherwise we try to connect using the passed address (failures to
bind other than EADDRNOTAVAIL will be ignored).
"""
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
success = False
if source is not None:
try:
sock.bind((source, 0))
except socket.error, (errcode):
if errcode == errno.EADDRNOTAVAIL:
success = False
sock.settimeout(timeout)
try:
sock.connect((target, port))
sock.close()
success = True
except socket.timeout:
success = False
except socket.error, (errcode):
success = (not live_port_needed) and (errcode == errno.ECONNREFUSED)
return success
def GetHosts(hostsfile):
"""Return list of hosts from hostfile.
Reads the hostslist file and returns a list of hosts.
Expects the hostslist file to contain one hostname per line.
"""
try:
datafile = open(hostsfile, "r")
except IOError, msg:
print "Failed to open hosts file %s: %s" % (hostsfile, msg)
sys.exit(2)
hosts = datafile.readlines()
datafile.close()
return hosts
def WriteLog(message, logfile):
"""Writes message, terminated by newline, to logfile."""
try:
logfile = open(logfile, "aw")
except IOError, msg:
print "failed to open log file %s: %s" % (logfile, msg)
print "log message was: %s" % message
sys.exit(1) # no being able to log is critical
try:
timestamp = GetTimeStamp()
logfile.writelines("%s %s\n" % (timestamp, message))
logfile.close()
except IOError, msg:
print "failed to write to logfile %s: %s" % (logfile, msg)
print "log message was: %s" % message
sys.exit(1) # no being able to log is critical
def GetAgentKeys():
"""Tries to get a list of ssh keys from an agent."""
try:
agent = paramiko.Agent()
return list(agent.get_keys())
except paramiko.SSHException:
return []
def SetupSshConnection(host, username, password, keys, logfile):
"""Setup the ssh connection used for all later steps.
This function sets up the ssh connection that will be used both
for upload and remote command execution.
On success, it will return paramiko.Transport object with an
already logged in session. On failure, False will be returned.
"""
# check if target is willing to talk to us at all
if not PingByTcp(host, 22, live_port_needed=True):
WriteLog("ERROR: FAILURE_NOT_REACHABLE", logfile)
print " - ERROR: host not reachable on 22/tcp"
return False
all_kwargs = [{"pkey": k} for k in keys]
all_desc = ["key %d" % d for d in range(len(keys))]
if password is not None:
all_kwargs.append({"password": password})
all_desc.append("password")
# deal with logging out of paramiko.transport
handler = None
for desc, kwargs in zip(all_desc, all_kwargs):
try:
transport = paramiko.Transport((host, 22))
# only try to setup the logging handler once
if not handler:
handler = logging.StreamHandler()
handler.setLevel(logging.ERROR)
log = logging.getLogger(transport.get_log_channel())
log.addHandler(handler)
transport.connect(username=username, **kwargs) # pylint: disable-msg=W0142
WriteLog("ssh connection established using %s" % desc, logfile)
# strange ... when establishing the session and the immediately
# setting up the channels for sftp & shell from that, it sometimes
# fails, but waiting 1 second after session setup makes it always work
# time.sleep(1)
# FIXME apparently needfull to give sshd some time
return transport
except (socket.gaierror, socket.error, paramiko.SSHException):
continue
methods = ", ".join(all_desc)
WriteLog("ERROR: FAILURE_CONNECTION_SETUP (tried %s) " % methods, logfile)
WriteLog("aborted", logfile)
print " - ERROR: connection setup failed (tried %s)" % methods
return False
def UploadFiles(connection, executable, filelist, logfile):
"""Uploads the specified files via sftp.
Uploads the specified files to a random, freshly created directory with
a temporary name under /tmp. All uploaded files are chmod 0400 after upload
with the exception of executable, with is chmod 500.
Upon success, returns the absolute path to the remote upload directory,
but will return False upon failure.
"""
remote_dir = "%s.%s-%s" % (REMOTE_PATH_BASE,
random.random(), random.random())
try:
sftp = paramiko.SFTPClient.from_transport(connection)
sftp.mkdir(remote_dir, mode=0700)
for item in filelist:
remote_file = "%s/%s" % (remote_dir, item.split("/").pop())
WriteLog("uploading %s to remote %s" % (item, remote_file), logfile)
sftp.put(item, remote_file)
if item == executable:
sftp.chmod(remote_file, 0500)
else:
sftp.chmod(remote_file, 0400)
sftp.close()
except IOError, err:
WriteLog("ERROR: FAILURE_UPLOAD: %s" % err, logfile)
return False
return remote_dir
def CleanupRemoteDir(connection, upload_dir, filelist, logfile):
"""Cleanes out and removes the remote work directory."""
try:
sftp = paramiko.SFTPClient.from_transport(connection)
for item in filelist:
fullpath = "%s/%s" % (upload_dir, item.split("/").pop())
WriteLog("removing remote %s" % fullpath, logfile)
sftp.remove(fullpath)
sftp.rmdir(upload_dir)
sftp.close()
except IOError, err:
WriteLog("ERROR: FAILURE_CLEANUP: %s" % err, logfile)
return False
return True
def RunRemoteCommand(connection, command, logfile):
"""Execute the command via ssh on the remote host."""
session = connection.open_session()
session.setblocking(0)
# the following dance is needed because paramiko changed APIs:
# from returning True/False for success to always returning None
# and throwing an exception in case of problems.
# And I want to support both the old and the new API.
result = True # being optimistic here, I know
message = None
try:
if session.exec_command("%s 2>&1" % command) is False:
result = False
except paramiko.SSHException, message:
result = False
if not result:
WriteLog("ERROR: FAILURE_COMMAND_EXECUTION: %s" % message, logfile)
return False
### Read when data is available
output = ""
while select.select([session], [], []):
data = session.recv(1024)
if not data:
break
output += data
select.select([], [], [], .1)
WriteLog("SUCCESS: command output follows", logfile)
for line in output.split("\n"):
WriteLog("output = %s" %line, logfile)
WriteLog("command execution completed", logfile)
session.close()
return True
def HostWorker(logdir, username, password, keys, hostname,
executable, command, filelist):
"""Per-host worker.
This function does not return - it's the main code of the childs,
which exit at the end of this function. The exit code 0 or 1 will be
interpreted by the parent.
Args:
logdir: the directory where the logfiles must be created
username: SSH username
password: SSH password
keys: SSH keys
hostname: the hostname to connect to
executable: the executable to upload, if not None
command: the command to run
filelist: auxiliary files to upload
"""
# in the child/worker process
logfile = "%s/%s.log" % (logdir, hostname)
print "%s - starting" % hostname
result = 0 # optimism, I know
try:
connection = SetupSshConnection(hostname, username,
password, keys, logfile)
if connection is not False:
if executable is not None:
print " %s: uploading files" % hostname
upload_dir = UploadFiles(connection, executable,
filelist, logfile)
command = "cd %s && ./%s" % (upload_dir,
executable.split("/").pop())
print " %s: executing remote command" % hostname
cmd_result = RunRemoteCommand(connection, command, logfile)
if cmd_result is True:
print " %s: remote command execution successful" % hostname
else:
print (" %s: remote command execution failed,"
" check log for details" % hostname)
result = 1
if executable is not None:
print " %s: cleaning up remote work dir" % hostname
cln_result = CleanupRemoteDir(connection, upload_dir,
filelist, logfile)
if cln_result is False:
print (" %s: remote work dir cleanup failed, check"
" log for details" % hostname)
result = 1
connection.close()
else:
print " %s: connection setup failed, skipping" % hostname
result = 1
except KeyboardInterrupt:
print " %s: received KeyboardInterrupt, aborting" % hostname
WriteLog("ERROR: ABORT_KEYBOARD_INTERRUPT", logfile)
result = 1
except Exception, err:
result = 1
trace = traceback.format_exc()
msg = "ERROR: UNHANDLED_EXECPTION_ERROR: %s\nTrace: %s" % (err, trace)
WriteLog(msg, logfile)
print " %s: %s" % (hostname, msg)
# and exit with exit code 0 or 1, so the parent can compute statistics
sys.exit(result)
def LaunchWorker(child_pids, logdir, username, password, keys, hostname,
executable, command, filelist):
"""Launch the per-host worker.
Arguments are the same as for HostWorker, except for child_pids,
which is a dictionary holding the pid-to-hostname mapping.
"""
hostname = hostname.rstrip("\n")
pid = os.fork()
if pid > 0:
# controller just record the pids
child_pids[pid] = hostname
else:
HostWorker(logdir, username, password, keys, hostname,
executable, command, filelist)
def main():
"""main."""
try:
optlist, _ = getopt.getopt(sys.argv[1:], "l:x:h:f:a:c:b:u:p:A")
except getopt.GetoptError, err:
print str(err)
ShowHelp(sys.argv[0])
sys.exit(2)
logdir = executable = hostfile = hostlist = command = None
use_agent = False
auxfiles = []
username = "root"
password = None
batch_size = 15
for option in optlist:
if option[0] == "-l":
logdir = option[1]
if option[0] == "-x":
executable = option[1]
if option[0] == "-f":
hostfile = option[1]
if option[0] == "-h":
hostlist = option[1]
if option[0] == "-a":
auxfiles.append(option[1])
if option[0] == "-c":
command = option[1]
if option[0] == "-b":
batch_size = int(option[1])
if option[0] == "-u":
username = option[1]
if option[0] == "-p":
password = option[1]
if option[0] == "-A":
use_agent = True
if not (logdir and (executable or command) and (hostfile or hostlist)):
print "error: missing required commandline argument(s)"
ShowHelp(sys.argv[0])
sys.exit(3)
if executable and command:
print "error: can run either a command or an executable, not both"
ShowHelp(sys.argv[0])
sys.exit(3)
if hostlist and hostfile:
print "error: specify either -f or -h arguments, not both"
ShowHelp(sys.argv[0])
sys.exit(3)
### Unbuffered sys.stdout
sys.stdout = os.fdopen(1, "w", 0)
if LogDirUseable(logdir) is False:
print "ERROR: cannot create logfiles in dir %s, aborting" % logdir
sys.exit(1)
keys = []
if use_agent:
keys = GetAgentKeys()
elif password:
try:
fh = file(password)
pwvalue = fh.readline().strip()
fh.close()
except IOError, e:
print "error: can not read in from password file %s: %s" % (password, e)
sys.exit(1)
password = pwvalue
else:
password = getpass.getpass("%s's password for all nodes: " % username)
if hostfile:
hosts = GetHosts(hostfile)
else:
if "," in hostlist:
hostlist = hostlist.rstrip(",") # commandline robustness