exscript

#!/usr/bin/env python
# Copyright (C) 2007-2010 Samuel Abels.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2, as
# published by the Free Software Foundation.
#
# 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
import sys
import os
import re
import imp
import getpass
import Exscript.protocols.drivers
from optparse import OptionParser, Option, OptionValueError
from Exscript import Queue, Account, PrivateKey, __version__
from Exscript.protocols import protocol_map
from Exscript.util import template
from Exscript.util.sigint import SigIntWatcher
from Exscript.util.cast import to_list, to_host
from Exscript.util.interact import get_login
from Exscript.util.log import log_to_file
from Exscript.util.file import get_accounts_from_file, \
                               get_hosts_from_file, \
                               get_hosts_from_csv
from Exscript.util.decorator import autologin

bracket_expression_re = re.compile(r'^\{([^\]]*)\}$')

def expand_bracket(value_name, value):
    match = bracket_expression_re.match(value)
    if match is None:
        return value
    prompt = match.group(1) or 'a value for "%s"' % value_name
    if prompt.startswith('!'):
        value = getpass.getpass('Please enter %s: ' % prompt[1:])
    else:
        value = raw_input('Please enter %s: ' % prompt)
    return value

def expand_host_variables(host):
    # Define host-specific variables.
    for key, value in host.get_all().iteritems():
        if isinstance(value, str):
            value = expand_bracket(key, value)
        elif hasattr(value, '__iter__'):
            for n in range(len(value)):
                if not isinstance(value[n], str):
                    continue
                value[n] = expand_bracket(key, value[n])
        host.set(key, value)

def run():
    # Parse options.
    options, args = parser.parse_args(sys.argv)
    args.pop(0)

    def mkhost(name):
        return to_host(name,
                       default_protocol = options.protocol,
                       default_domain   = options.default_domain)

    def mkhosts_from_file(filename):
        return get_hosts_from_file(options.hosts,
                                   default_protocol = options.protocol,
                                   default_domain   = options.default_domain)

    def mkhosts_from_csv(filename):
        return get_hosts_from_csv(options.csv_hosts,
                                  default_protocol = options.protocol,
                                  default_domain   = options.default_domain)

    # Extract the hostnames out of the command line arguments.
    filename = None
    if not options.execute:
        try:
            filename = args.pop(0)
        except IndexError, e:
            parser.error('Missing filename')
    hosts = [mkhost(h) for h in args]

    # If a filename containing hostnames AND VARIABLES was given, read it.
    if options.csv_hosts:
        try:
            csv_hosts = mkhosts_from_csv(options.csv_hosts)
        except IOError, e:
            parser.error(str(e))
        if not csv_hosts:
            print 'Warning: %s is empty.' % options.csv_hosts
        hosts += csv_hosts

    # If a filename containing hostnames was given, read it.
    if options.hosts:
        try:
            txt_hosts = mkhosts_from_file(options.hosts)
        except IOError, e:
            parser.error(str(e))
        except ValueError, e:
            parser.error(e)
        if not txt_hosts:
            print 'Warning: %s is empty.' % options.hosts
        hosts += txt_hosts

    # If a filename of an Exscript driver was given, import it.
    if options.load_driver:
        print 'Searching drivers in %s...' % options.load_driver
        name = os.path.splitext(os.path.basename(options.load_driver))[0]
        try:
            driver_module = imp.load_source(name, options.load_driver)
        except IOError, e:
            parser.error(str(e))
        except Exception, e:
            sys.stderr.write('Error in driver ' + options.load_driver + '\n')
            raise
        for name, obj in driver_module.__dict__.iteritems():
            if Exscript.protocols.drivers.isdriver(obj):
                Exscript.protocols.drivers.add_driver(obj)
                print 'Driver ' + repr(name) + ' added.'

    # Make sure that all mandatory options are present.
    if not hosts:
        parser.error('No hosts to connect to')

    # Set host options.
    for host in hosts:
        host.set_option('debug', options.protocol_verbose)
        host.set_option('verify_fingerprint', not options.ssh_auto_verify)

    # Read the Exscript.
    if options.execute:
        script_content = options.execute
    else:
        file           = open(filename, 'r')
        script_content = file.read()
        file.close()

    # Prepare the code that is executed after the user script has completed.
    #FIXME: Move into the library, then use read_template_from_file instead of read_template().
    if not options.no_auto_logout:
        script_content += r'''
    ## Exscript generated commands. ##
    {if connection.guess_os() is "vrp"}
        {connection.sendline("quit")}
    {else}
        {connection.sendline("exit")}
    {end}'''

    # Test whether the template compiles.
    vars = options.define.copy()
    if filename:
        vars['__filename__'] = filename
    vars.update(hosts[0].get_all())
    try:
        template.test(script_content, **vars)
    except Exception, e:
        if options.parser_verbose > 0:
            raise
        parser.error(str(e))

    # Create Exscript.
    queue = Queue(domain      = options.default_domain,
                  mode        = 'multiprocessing',
                  verbose     = options.verbose,
                  max_threads = options.connections)
    default_pool = queue.account_manager.default_pool

    # Read the account pool file.
    try:
        if options.account_pool:
            accounts = get_accounts_from_file(options.account_pool)
            default_pool.add_account(accounts)
    except IOError, e:
        parser.error(str(e))
    if options.account_pool and default_pool.n_accounts() == 0:
        msg = r'WARNING: No accounts found in account pool file (%s)!'
        print msg % options.account_pool

    # Read username and password.
    if options.non_interactive or default_pool.n_accounts() > 0:
        user      = None
        password  = None
        password2 = None
    else:
        try:
            user, password = get_login()
        except KeyboardInterrupt:
            sys.exit(1)
        if options.authorization:
            prompt    = 'Please enter your authorization password: '
            password2 = getpass.getpass(prompt)
        else:
            password2 = password

    # Read the SSH key.
    if options.ssh_key:
        print "Reading key from", options.ssh_key
        try:
            key = PrivateKey.from_file(options.ssh_key, password)
        except ValueError, e:
            parser.error(str(e))
        if user is None:
            user = getpass.getuser()
    else:
        key = None

    # Add the account to the pool.
    if user is not None:
        account = Account(user, password, password2, key = key)
        default_pool.add_account(account)

    # Ask for values of marked variables.
    for host in hosts:
        expand_host_variables(host)
    for key, val in options.define.iteritems():
        options.define[key] = expand_bracket(key, val)

    # Choose the template processing type.
    tmpl_vars = options.define
    if options.no_prompt:
        def function(job, host, conn, **kwargs):
            kwargs.update(tmpl_vars)
            kwargs.update(host.get_all())
            return template.paste(conn, script_content, **kwargs)
    else:
        strip = not options.no_strip
        def function(job, host, conn, **kwargs):
            kwargs.update(tmpl_vars)
            kwargs.update(host.get_all())
            return template.eval(conn, script_content, strip, **kwargs)

    # Wrap the template processor such that the login procedure is automated.
    if not options.no_authentication:
        attempts  = options.retry_login + 1
        decorator = autologin(attempts = attempts)
        function  = decorator(function)

    # Wrap the template processor such that logging is enabled.
    if options.logdir:
        # Create the log directory.
        if not os.path.exists(options.logdir):
            print 'Creating log directory (%s)...' % options.logdir
            try:
                os.makedirs(options.logdir)
            except IOError, e:
                parser.error(str(e))

        # Enable logging.
        mode      = options.overwrite_logs and 'w' or 'a'
        decorator = log_to_file(options.logdir, mode, options.delete_logs)
        function  = decorator(function)

    # Wait until the specified time. We are using os.system because
    # it allows for specifying absolute times, not just the number
    # of seconds like Python's time.sleep().
    if options.sleep:
        print "Waiting for %s..." % options.sleep,
        sys.stdout.flush()
        os.system('sleep %s' % options.sleep)
        print "time expired, starting script."

    # Run the template.
    for host in hosts:
        queue.run(host, function, attempts = options.retry + 1)
    queue.join()
    failed = queue.failed
    queue.destroy()
    return failed

# Define command line option value types.
def check_assignment(option, opt, value):
    if not re.match(r'\S+=\S+', value):
        raise OptionValueError('option %s: invalid value: %r' % (opt, value))
    return value

def check_protocol(option, opt, value):
    if value not in protocol_map:
        raise OptionValueError('option %s: invalid value: %r' % (opt, value))
    return value

class AssignmentOption(Option):
    # Define a new 'assignment' type for the '--define' command line option.
    TYPES                      = Option.TYPES + ('assignment', 'protocol')
    TYPE_CHECKER               = Option.TYPE_CHECKER.copy()
    TYPE_CHECKER['assignment'] = check_assignment
    TYPE_CHECKER['protocol']   = check_protocol

    # Define a new store action that parses 'assignment' values.
    ACTIONS       = Option.ACTIONS + ('store_dict',)
    STORE_ACTIONS = Option.STORE_ACTIONS + ('store_dict',)
    TYPED_ACTIONS = Option.TYPED_ACTIONS + ('store_dict',)

    def take_action(self, action, dest, opt, value, values, parser):
        if action == "store_dict":
            left, right = value.split("=")
            values.ensure_value(dest, {})[left] = right
            return
        Option.take_action(self,
                           action,
                           dest,
                           opt,
                           value,
                           values,
                           parser)

# Define the command line syntax.
usage  = '%prog [options] filename [hostname [hostname ...]]'
usage += '\nCopyright (C) 2007-2010 by Samuel Abels.'
parser = OptionParser(usage        = usage,
                      version      = __version__,
                      option_class = AssignmentOption)

parser.add_option('--account-pool',
                  dest    = 'account_pool',
                  metavar = 'FILE',
                  help    = '''
Reads the user/password combination from the given file
instead of prompting on the command line. The file may
also contain more than one user/password combination, in
which case the accounts are used round robin.
'''.strip())

parser.add_option('--connections', '-c',
                  dest    = 'connections',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 1,
                  help    = '''
Maximum number of concurrent connections.
NUM is a number between 1 and 20, default is 1.
'''.strip())

parser.add_option('--csv-hosts',
                  dest    = 'csv_hosts',
                  metavar = 'FILE',
                  help    = '''
Loads a list of hostnames and definitions from the given file.
The first line of the file must have the column headers in the
following syntax: "hostname [variable] [variable] ...", where
the fields are separated by tabs, "hostname" is the keyword
"hostname" and "variable" is a unique name under which the
column is accessed in the script.
The following lines contain the hostname in the first column,
and the values of the variables in the following columns.
'''.strip())

parser.add_option('--define', '-d',
                  dest    = 'define',
                  type    = 'assignment',
                  action  = 'store_dict',
                  default = {},
                  metavar = 'PAIR',
                  help    = '''
Defines a variable that is passed to the script.
PAIR has the following syntax: STRING=STRING.
'''.strip())

parser.add_option('--default-domain',
                  dest    = 'default_domain',
                  metavar = 'STRING',
                  default = '',
                  help    = '''
The IP domain name that is used if a given hostname has no domain appended.
'''.strip())

parser.add_option('--delete-logs',
                  dest    = 'delete_logs',
                  action  = 'store_true',
                  default = False,
                  help    = 'Delete logs of successful operations when done.')

parser.add_option('--load-driver',
                  dest    = 'load_driver',
                  metavar = 'FILE',
                  help    = '''
A python file containing an Exscript driver class.
'''.strip())

parser.add_option('--execute', '-e',
                  dest    = 'execute',
                  metavar = 'EXSCRIPT',
                  help    = 'Interprets the given string as the script.')

parser.add_option('--hosts',
                  dest    = 'hosts',
                  metavar = 'FILE',
                  help    = '''
Loads a list of hostnames from the given file (one host per line).
'''.strip())

parser.add_option('--non-interactive', '-i',
                  dest    = 'non_interactive',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Do not ask for a username or password, but still try to authenticate.
May be used if the login credentials are passed as part of a URI formatted
hostname.
'''.strip())

parser.add_option('--logdir', '-l',
                  dest    = 'logdir',
                  metavar = 'DIR',
                  help    = '''
Logs any communication into the directory with the given name.
Each filename consists of the hostname with ".log" appended.
Errors are written to a separate file, where the filename
consists of the hostname with ".log.error" appended.
'''.strip())

parser.add_option('--no-authentication', '-n',
                  dest    = 'no_authentication',
                  action  = 'store_true',
                  default = False,
                  help    = '''
When given, the automatic authentication procedure is skipped. Implies -i.
'''.strip())

parser.add_option('--authorization',
                  dest    = 'authorization',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Ask for an authorization password in addition to the authentication password.
'''.strip())

parser.add_option('--no-auto-logout',
                  dest    = 'no_auto_logout',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Do not attempt to execute the exit or quit command at the end of a script.
'''.strip())

parser.add_option('--no-prompt',
                  dest    = 'no_prompt',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Do not wait for a prompt anywhere (except during the authentication
procedure). Note that this will also cause Exscript to disable commands
that require a prompt, such as "extract".
'''.strip())

parser.add_option('--no-strip',
                  dest    = 'no_strip',
                  action  = 'store_true',
                  default = False,
                  help    = 'Do not strip the first line of each response.')

parser.add_option('--overwrite-logs',
                  dest    = 'overwrite_logs',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Instructs Exscript to overwrite existing logfiles. The default
is to append the output if a log already exists.
'''.strip())

protocols = protocol_map.keys()
protocols.sort()
parser.add_option('--protocol', '-p',
                  dest    = 'protocol',
                  type    = 'protocol',
                  metavar = 'STRING',
                  default = 'telnet',
                  help    = '''
Specify which protocol to use to connect to the remote host.
Allowed values for STRING include: %s.
The default protocol is telnet.
'''.strip() % ', '.join(protocols))

parser.add_option('--retry',
                  dest    = 'retry',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 0,
                  help    = '''
Defines the number of retries per host on failure. Default is 0.
'''.strip())

parser.add_option('--retry-login',
                  dest    = 'retry_login',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 0,
                  help    = '''
Defines the number of retries per host on login failure. Default is 0.
'''.strip())

parser.add_option('--sleep',
                  dest    = 'sleep',
                  metavar = 'TIME',
                  default = '',
                  help    = '''
Waits for the specified time before running the script.
TIME is a timespec as specified by the 'sleep' Unix command.
'''.strip())

parser.add_option('--ssh-auto-verify',
                  dest    = 'ssh_auto_verify',
                  action  = 'store_true',
                  default = False,
                  help    = '''
Automatically confirms the 'Host key changed' SSH error 
message with 'yes'. Highly insecure and not recommended.
'''.strip())

parser.add_option('--ssh-key',
                  dest    = 'ssh_key',
                  metavar = 'FILE',
                  help    = '''
Specify a key file that is passed to the SSH client.
This is equivalent to using the "-i" parameter of the
openssh command line client.
'''.strip())

parser.add_option('--verbose', '-v',
                  dest    = 'verbose',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 1,
                  help    = '''
Print out debug information about the queue.
NUM is a number between 0 (min) and 5 (max). Default is 1.
'''.strip())

parser.add_option('--parser-verbose', '-V',
                  dest    = 'parser_verbose',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 0,
                  help    = '''
Print out debug information about the Exscript template parser.
NUM is a number between 0 (min) and 5 (max). Default is 0.
'''.strip())

parser.add_option('--protocol-verbose',
                  dest    = 'protocol_verbose',
                  type    = 'int',
                  metavar = 'NUM',
                  default = 0,
                  help    = '''
Print out debug information about the network activity.
NUM is a number between 0 (min) and 5 (max). Default is 1.
'''.strip())

if __name__ == '__main__':
    SigIntWatcher()
    failed = run()
    if failed != 0:
        sys.exit('error: %d actions failed.' % failed)