ceph.in

#!@PYTHON_EXECUTABLE@
# -*- mode:python -*-
# vim: ts=4 sw=4 smarttab expandtab
#
# Processed in Makefile to add python #! line and version variable
#
#


"""
ceph.in becomes ceph, the command-line management tool for Ceph clusters.
This is a replacement for tools/ceph.cc and tools/common.cc.

Copyright (C) 2013 Inktank Storage, Inc.

This 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.  See file COPYING.
"""

import os
import sys
import platform

CEPH_GIT_VER="@CEPH_GIT_VER@"
CEPH_GIT_NICE_VER="@CEPH_GIT_NICE_VER@"

# Make life easier on developers:
# If in src/, and .libs and pybind exist here, assume we're running
# from a Ceph source dir and tweak PYTHONPATH and LD_LIBRARY_PATH
# to use local files

MYPATH = os.path.abspath(__file__)
MYDIR = os.path.dirname(MYPATH)
DEVMODEMSG = '*** DEVELOPER MODE: setting PATH, PYTHONPATH and LD_LIBRARY_PATH ***'

def respawn_in_path(lib_path, pybind_path):
    execv_cmd = ['python']
    if 'CEPH_DBG' in os.environ:
        execv_cmd += ['-mpdb']

    if platform.system() == "Darwin":
        lib_path_var = "DYLD_LIBRARY_PATH"
    else:
        lib_path_var = "LD_LIBRARY_PATH"

    py_binary = os.environ.get("PYTHON", "python")

    if lib_path_var in os.environ:
        if lib_path not in os.environ[lib_path_var]:
            os.environ[lib_path_var] += ':' + lib_path
            print >> sys.stderr, DEVMODEMSG
            os.execvp(py_binary, execv_cmd + sys.argv)
    else:
        os.environ[lib_path_var] = lib_path
        print >> sys.stderr, DEVMODEMSG
        os.execvp(py_binary, execv_cmd + sys.argv)
    sys.path.insert(0, os.path.join(MYDIR, pybind_path))

if MYDIR.endswith('src') and \
   os.path.exists(os.path.join(MYDIR, '.libs')) and \
   os.path.exists(os.path.join(MYDIR, 'pybind')):

    respawn_in_path(os.path.join(MYDIR, '.libs'), "pybind")
    if os.environ.has_key('PATH') and MYDIR not in os.environ['PATH']:
        os.environ['PATH'] += ':' + MYDIR

elif os.path.exists(os.path.join(os.getcwd(), "CMakeCache.txt")) \
     and os.path.exists(os.path.join(os.getcwd(), "init-ceph")):
    src_path = None
    for l in open("./CMakeCache.txt").readlines():
        if l.startswith("Ceph_SOURCE_DIR:STATIC="):
            src_path = l.split("=")[1].strip()

    if src_path is None:
        # Huh, maybe we're not really in a cmake environment?
        pass
    else:
        # Developer mode, but in a cmake build dir instead of the src dir
        lib_path = os.path.join(os.getcwd(), "src")
        pybind_path = os.path.join(src_path, "src", "pybind")
        respawn_in_path(lib_path, pybind_path)

    sys.path.insert(0, os.path.join(MYDIR, pybind_path))

    # Add src/ to path for e.g. ceph-conf
    if os.environ.has_key('PATH') and lib_path not in os.environ['PATH']:
        os.environ['PATH'] += ':' + lib_path

import argparse
import errno
import json
import rados
import shlex
import signal
import string
import subprocess

from ceph_argparse import \
    concise_sig, descsort, parse_json_funcsigs, \
    matchnum, validate_command, find_cmd_target, \
    send_command, json_command

from ceph_daemon import DaemonWatcher, admin_socket

# just a couple of globals

verbose = False
cluster_handle = None

############################################################################

def osdids():
    ret, outbuf, outs = json_command(cluster_handle, prefix='osd ls')
    if ret == -errno.EINVAL:
        # try old mon
        ret, outbuf, outs = send_command(cluster_handle, cmd=['osd', 'ls'])
    if ret:
        raise RuntimeError('Can\'t contact mon for osd list')
    return [i for i in outbuf.split('\n') if i != '']

def monids():
    ret, outbuf, outs = json_command(cluster_handle, prefix='mon dump',
                                     argdict={'format':'json'})
    if ret == -errno.EINVAL:
        # try old mon
        ret, outbuf, outs = send_command(cluster_handle,
                                         cmd=['mon', 'dump', '--format=json'])
    if ret:
        raise RuntimeError('Can\'t contact mon for mon list')
    d = json.loads(outbuf)
    return [m['name'] for m in d['mons']]

def mdsids():
    ret, outbuf, outs = json_command(cluster_handle, prefix='mds dump',
                                     argdict={'format':'json'})
    if ret == -errno.EINVAL:
        # try old mon
        ret, outbuf, outs = send_command(cluster_handle,
                                         cmd=['mds', 'dump', '--format=json'])
    if ret:
        raise RuntimeError('Can\'t contact mon for mds list')
    d = json.loads(outbuf)
    l = []
    infodict = d['info']
    for mdsdict in infodict.values():
        l.append(mdsdict['name'])
    return l

# these args must be passed to all child programs
GLOBAL_ARGS = {
    'client_id': '--id',
    'client_name': '--name',
    'cluster': '--cluster',
    'cephconf': '--conf',
}

def parse_cmdargs(args=None, target=''):
    # alias: let the line-wrapping be sane
    AP = argparse.ArgumentParser

    # format our own help
    parser = AP(description='Ceph administration tool', add_help=False)

    parser.add_argument('--completion', action='store_true',
                        help=argparse.SUPPRESS)

    parser.add_argument('-h', '--help', help='request mon help',
                        action='store_true')

    parser.add_argument('-c', '--conf', dest='cephconf',
                        help='ceph configuration file')
    parser.add_argument('-i', '--in-file', dest='input_file',
                        help='input file')
    parser.add_argument('-o', '--out-file', dest='output_file',
                        help='output file')

    parser.add_argument('--id', '--user', dest='client_id',
                        help='client id for authentication')
    parser.add_argument('--name', '-n', dest='client_name',
                        help='client name for authentication')
    parser.add_argument('--cluster', help='cluster name')

    parser.add_argument('--admin-daemon', dest='admin_socket',
                        help='submit admin-socket commands (\"help\" for help')
    parser.add_argument('--admin-socket', dest='admin_socket_nope',
                        help='you probably mean --admin-daemon')

    parser.add_argument('-s', '--status', action='store_true',
                        help='show cluster status')

    parser.add_argument('-w', '--watch', action='store_true',
                        help='watch live cluster changes')
    parser.add_argument('--watch-debug', action='store_true',
                        help='watch debug events')
    parser.add_argument('--watch-info', action='store_true',
                        help='watch info events')
    parser.add_argument('--watch-sec', action='store_true',
                        help='watch security events')
    parser.add_argument('--watch-warn', action='store_true',
                        help='watch warn events')
    parser.add_argument('--watch-error', action='store_true',
                        help='watch error events')

    parser.add_argument('--version', '-v', action="store_true", help="display version")
    parser.add_argument('--verbose', action="store_true", help="make verbose")
    parser.add_argument('--concise', dest='verbose', action="store_false",
                        help="make less verbose")

    parser.add_argument('-f', '--format', choices=['json', 'json-pretty',
                        'xml', 'xml-pretty', 'plain'], dest='output_format')

    parser.add_argument('--connect-timeout', dest='cluster_timeout',
                        type=int,
                        help='set a timeout for connecting to the cluster')

    # returns a Namespace with the parsed args, and a list of all extras
    parsed_args, extras = parser.parse_known_args(args)

    return parser, parsed_args, extras


def hdr(s):
    print '\n', s, '\n', '=' * len(s)

def do_basic_help(parser, args):
    """
    Print basic parser help
    If the cluster is available, get and print monitor help
    """
    hdr('General usage:')
    parser.print_help()

def do_extended_help(parser, args):
    def help_for_sigs(sigs, partial=None):
        sys.stdout.write(format_help(parse_json_funcsigs(sigs, 'cli'),
                         partial=partial))

    def help_for_target(target, partial=None):
        ret, outbuf, outs = json_command(cluster_handle, target=target,
                                         prefix='get_command_descriptions',
                                         timeout=10)
        if ret:
            print >> sys.stderr, \
                "couldn't get command descriptions for {0}: {1}".\
                format(target, outs)
        else:
            help_for_sigs(outbuf, partial)

    partial = ' '.join(args)
    if (cluster_handle.state == "connected"):
        help_for_target(target=('mon', ''), partial=partial)
    return 0

DONTSPLIT = string.letters + '{[<>]}'

def wrap(s, width, indent):
    """
    generator to transform s into a sequence of strings width or shorter,
    for wrapping text to a specific column width.
    Attempt to break on anything but DONTSPLIT characters.
    indent is amount to indent 2nd-through-nth lines.

    so "long string long string long string" width=11 indent=1 becomes
    'long string', ' long string', ' long string' so that it can be printed
    as
    long string
     long string
     long string

    Consumes s.
    """
    result = ''
    leader = ''
    while len(s):

        if (len(s) <= width):
            # no splitting; just possibly indent
            result = leader + s
            s = ''
            yield result

        else:
            splitpos = width
            while (splitpos > 0) and (s[splitpos-1] in DONTSPLIT):
                splitpos -= 1

            if splitpos == 0:
                splitpos = width

            if result:
                # prior result means we're mid-iteration, indent
                result = leader
            else:
                # first time, set leader and width for next
                leader = ' ' * indent
                width -= 1      # for subsequent space additions

            # remove any leading spaces in this chunk of s
            result += s[:splitpos].lstrip()
            s = s[splitpos:]

            yield result

    raise StopIteration

def format_help(cmddict, partial=None):
    """
    Formats all the cmdsigs and helptexts from cmddict into a sorted-by-
    cmdsig 2-column display, with each column wrapped and indented to
    fit into 40 characters.
    """

    fullusage = ''
    for cmd in sorted(cmddict.itervalues(), cmp=descsort):

        if not cmd['help']:
            continue
        concise = concise_sig(cmd['sig'])
        if partial and not concise.startswith(partial):
            continue
        siglines = [l for l in wrap(concise, 40, 1)]
        helplines = [l for l in wrap(cmd['help'], 39, 1)]

        # make lists the same length
        maxlen = max(len(siglines), len(helplines))
        siglines.extend([''] * (maxlen - len(siglines)))
        helplines.extend([''] * (maxlen - len(helplines)))

        # so we can zip them for output
        for (s, h) in zip(siglines, helplines):
            fullusage += '{0:40s} {1}\n'.format(s, h)

    return fullusage


def ceph_conf(parsed_args, field, name):
    args=['ceph-conf']

    if name:
        args.extend(['--name', name])

    # add any args in GLOBAL_ARGS
    for key, val in GLOBAL_ARGS.iteritems():
        # ignore name in favor of argument name, if any
        if name and key == 'client_name':
            continue
        if getattr(parsed_args, key):
            args.extend([val, getattr(parsed_args, key)])

    args.extend(['--show-config-value', field])
    p = subprocess.Popen(
        args,
        stdout=subprocess.PIPE,
        stderr=subprocess.PIPE)
    outdata, errdata = p.communicate()
    if (len(errdata)):
        raise RuntimeError('unable to get conf option %s for %s: %s' % (field, name, errdata))
    return outdata.rstrip()

PROMPT = 'ceph> '

if sys.stdin.isatty():
    def read_input():
        while True:
            line = raw_input(PROMPT).rstrip()
            if line in ['q', 'quit', 'Q', 'exit']:
                return None
            if line:
                return line
else:
    def read_input():
        while True:
            line = sys.stdin.readline()
            if not line:
                return None
            line = line.rstrip()
            if line:
                return line


def new_style_command(parsed_args, cmdargs, target, sigdict, inbuf, verbose):
    """
    Do new-style command dance.
    target: daemon to receive command: mon (any) or osd.N
    sigdict - the parsed output from the new monitor describing commands
    inbuf - any -i input file data
    verbose - bool
    """
    if verbose:
        for cmdtag in sorted(sigdict.keys()):
            cmd = sigdict[cmdtag]
            sig = cmd['sig']
            print '{0}: {1}'.format(cmdtag, concise_sig(sig))

    got_command = False

    if not got_command:
        if cmdargs:
            # Validate input args against list of sigs
            valid_dict = validate_command(sigdict, cmdargs, verbose)
            if valid_dict:
                got_command = True
                if parsed_args.output_format:
                    valid_dict['format'] = parsed_args.output_format
            else:
                return -errno.EINVAL, '', 'invalid command'
        else:
            if sys.stdin.isatty():
                # do the command-interpreter looping
                # for raw_input to do readline cmd editing
                import readline  # noqa

            while True:
                interactive_input = read_input()
                if interactive_input is None:
                    return 0, '', ''
                cmdargs = parse_cmdargs(shlex.split(interactive_input))[2]
                try:
                    target = find_cmd_target(cmdargs)
                except Exception as e:
                    print >> sys.stderr, \
                            'error handling command target: {0}'.format(e)
                    return 1, '', ''
                valid_dict = validate_command(sigdict, cmdargs, verbose)
                if valid_dict:
                    if parsed_args.output_format:
                        valid_dict['format'] = parsed_args.output_format
                    if verbose:
                        print >> sys.stderr, "Submitting command ", valid_dict
                    ret, outbuf, outs = json_command(cluster_handle,
                                                     target=target,
                                                     argdict=valid_dict)
                    if ret:
                        ret = abs(ret)
                        print >> sys.stderr, \
                            'Error: {0} {1}'.format(ret, errno.errorcode.get(ret, 'Unknown'))
                    if outbuf:
                        print outbuf
                    if outs:
                        print >> sys.stderr, 'Status:\n', outs
                else:
                    print >> sys.stderr, "Invalid command"

    if verbose:
        print >> sys.stderr, "Submitting command ", valid_dict
    return json_command(cluster_handle, target=target, argdict=valid_dict,
                        inbuf=inbuf)

def complete(sigdict, args, target):
    """
    Command completion.  Match as much of [args] as possible,
    and print every possible match separated by newlines.
    Return exitcode.
    """
    # XXX this looks a lot like the front of validate_command().  Refactor?

    complete_verbose = 'COMPVERBOSE' in os.environ

    # Repulsive hack to handle tell: lop off 'tell' and target
    # and validate the rest of the command.  'target' is already
    # determined in our callers, so it's ok to remove it here.
    if len(args) and args[0] == 'tell':
        args = args[2:]
    # look for best match, accumulate possibles in bestcmds
    # (so we can maybe give a more-useful error message)
    best_match_cnt = 0
    bestcmds = []
    for cmdtag, cmd in sigdict.iteritems():
        sig = cmd['sig']
        matched = matchnum(args, sig, partial=True)
        if (matched > best_match_cnt):
            if complete_verbose:
                print >> sys.stderr, \
                    "better match: {0} > {1}: {2}:{3} ".format(matched,
                                  best_match_cnt, cmdtag, concise_sig(sig))
            best_match_cnt = matched
            bestcmds = [{cmdtag:cmd}]
        elif matched == best_match_cnt:
            if complete_verbose:
                print >> sys.stderr, \
                    "equal match: {0} > {1}: {2}:{3} ".format(matched,
                                  best_match_cnt, cmdtag, concise_sig(sig))
            bestcmds.append({cmdtag:cmd})

    # look through all matching sigs
    comps = []
    for cmddict in bestcmds:
        for cmd in cmddict.itervalues():
            sig = cmd['sig']
            # either:
            #   we match everything fully, so we want the next desc, or
            #   we match more partially, so we want the partial match
            fullindex = matchnum(args, sig, partial=False) - 1
            partindex = matchnum(args, sig, partial=True) - 1
            if complete_verbose:
                print >> sys.stderr, '{}: f {} p {} len {}'.format(sig, fullindex, partindex, len(sig))
            if fullindex == partindex and fullindex + 1 < len(sig):
                d = sig[fullindex + 1]
            else:
                d = sig[partindex]
            comps.append(str(d))
    if complete_verbose:
        print >> sys.stderr, '\n'.join(comps)
    print '\n'.join(comps)

    return 0

###
# ping a monitor
###
def ping_monitor(cluster_handle, name, timeout):
    if 'mon.' not in name:
        print >> sys.stderr, '"ping" expects a monitor to ping; try "ping mon.<id>"'
        return 1

    mon_id = name[len('mon.'):]
    if (mon_id == '*') :
        cluster_handle.connect(timeout=timeout)
        for m in monids() :
            s = cluster_handle.ping_monitor(m)
            print "mon.{0}".format(m) + '\n' + s
    else :
            s = cluster_handle.ping_monitor(mon_id)
            print s
    return 0

###
# main
###

def main():
    ceph_args = os.environ.get('CEPH_ARGS')
    if ceph_args:
        if "injectargs" in sys.argv:
            i = sys.argv.index("injectargs")
            sys.argv = sys.argv[:i] + ceph_args.split() + sys.argv[i:]
        else:
            sys.argv.extend(ceph_args.split())
    parser, parsed_args, childargs = parse_cmdargs()

    if parsed_args.version:
        print 'ceph version {0} ({1})'.format(CEPH_GIT_NICE_VER, CEPH_GIT_VER)  # noqa
        return 0

    global verbose
    verbose = parsed_args.verbose

    if verbose:
        print >> sys.stderr, "parsed_args: {0}, childargs: {1}".format(parsed_args, childargs)

    if parsed_args.admin_socket_nope:
        print >> sys.stderr, '--admin-socket is used by daemons; '\
        'you probably mean --admin-daemon/daemon'
        return 1

    # pass on --id, --name, --conf
    name = 'client.admin'
    if parsed_args.client_id:
        name = 'client.' + parsed_args.client_id
    if parsed_args.client_name:
        name = parsed_args.client_name

    # default '' means default conf search
    conffile = ''
    if parsed_args.cephconf:
        conffile = parsed_args.cephconf
    # For now, --admin-daemon is handled as usual.  Try it
    # first in case we can't connect() to the cluster

    format = parsed_args.output_format

    daemon_perf = False
    sockpath = None
    if parsed_args.admin_socket:
        sockpath = parsed_args.admin_socket
    elif len(childargs) > 0 and childargs[0] in ["daemon", "daemonperf"]:
        daemon_perf = (childargs[0] == "daemonperf")
        # Treat "daemon <path>" or "daemon <name>" like --admin_daemon <path>
        # Handle "daemonperf <path>" the same but requires no trailing args
        require_args = 2 if daemon_perf else 3
        if len(childargs) >= require_args:
            if childargs[1].find('/') >= 0:
                sockpath = childargs[1]
            else:
                # try resolve daemon name
                try:
                    sockpath = ceph_conf(parsed_args, 'admin_socket',
                                         childargs[1])
                except Exception as e:
                    print >> sys.stderr, \
                        'Can\'t get admin socket path: ' + str(e)
                    return errno.EINVAL
            # for both:
            childargs = childargs[2:]
        else:
            print >> sys.stderr, '{0} requires at least {1} arguments'.format(
                childargs[0], require_args)
            return errno.EINVAL

    if sockpath and daemon_perf:
        interval = 1
        count = None
        if len(childargs) > 0:
            try:
                interval = float(childargs[0])
                if interval < 0:
                    raise ValueError
            except ValueError:
                print >> sys.stderr, 'daemonperf: interval should be a positive number'
                return errno.EINVAL
        if len(childargs) > 1:
            if not childargs[1].isdigit():
                print >> sys.stderr, 'daemonperf: count should be a positive integer'
                return errno.EINVAL
            count = int(childargs[1])
        DaemonWatcher(sockpath).run(interval, count)
        return 0
    elif sockpath:
        try:
            print admin_socket(sockpath, childargs, format)
        except Exception as e:
            print >> sys.stderr, 'admin_socket: {0}'.format(e)
            return errno.EINVAL
        return 0

    timeout = None
    if parsed_args.cluster_timeout:
        timeout = parsed_args.cluster_timeout

    # basic help
    if parsed_args.help:
        do_basic_help(parser, childargs)

    # handle any 'generic' ceph arguments that we didn't parse here
    global cluster_handle

    # rados.Rados() will call rados_create2, and then read the conf file,
    # and then set the keys from the dict.  So we must do these
    # "pre-file defaults" first (see common_preinit in librados)
    conf_defaults = {
        'log_to_stderr':'true',
        'err_to_stderr':'true',
        'log_flush_on_exit':'true',
    }

    if 'injectargs' in childargs:
        position = childargs.index('injectargs')
        injectargs = childargs[position:]
        childargs = childargs[:position]
        if verbose:
            print >> sys.stderr, 'Separate childargs {0} from injectargs {1}'.\
                format(childargs, injectargs)
    else:
        injectargs = None

    clustername = 'ceph'
    if parsed_args.cluster:
        clustername = parsed_args.cluster

    try:
        cluster_handle = rados.Rados(name=name, clustername=clustername,
                                     conf_defaults=conf_defaults,
                                     conffile=conffile)
        retargs = cluster_handle.conf_parse_argv(childargs)
    except rados.Error as e:
        print >> sys.stderr, 'Error initializing cluster client: {0}'.\
            format(repr(e))
        return 1

    childargs = retargs
    if not childargs:
        childargs = []

    # -- means "stop parsing args", but we don't want to see it either
    if '--' in childargs:
        childargs.remove('--')
    if injectargs and '--' in injectargs:
        injectargs.remove('--')

    # special deprecation warning for 'ceph <type> tell'
    # someday 'mds' will be here too
    if len(childargs) >= 2 and \
        childargs[0] in ['mon', 'osd'] and \
        childargs[1] == 'tell':
        print >> sys.stderr, '"{0} tell" is deprecated; try "tell {0}.<id> <command> [options...]" instead (id can be "*") '.format(childargs[0])
        return 1

    if childargs in [['mon'], ['osd']]:
        parsed_args.help = True

    if parsed_args.help:
        # short default timeout for -h
        if not timeout:
            timeout = 5

        hdr('Monitor commands:')
        print '[Contacting monitor, timeout after %d seconds]' % timeout

    if childargs and childargs[0] == 'ping':
        if len(childargs) < 2:
            print >> sys.stderr, '"ping" requires a monitor name as argument: "ping mon.<id>"'
            return 1

    try:
        if childargs and childargs[0] == 'ping':
            return ping_monitor(cluster_handle, childargs[1], timeout)
        cluster_handle.connect(timeout=timeout)
    except KeyboardInterrupt:
        print >> sys.stderr, 'Cluster connection aborted'
        return 1
    except Exception as e:
        print >> sys.stderr, 'Error connecting to cluster: {0}'.\
            format(e.__class__.__name__)
        return 1

    if parsed_args.help:
        return do_extended_help(parser, childargs)

    # implement -w/--watch_*
    # This is ugly, but Namespace() isn't quite rich enough.
    level = ''
    for k, v in parsed_args._get_kwargs():
        if k.startswith('watch') and v:
            if k == 'watch':
                level = 'info'
            else:
                level = k.replace('watch_', '')
    if level:

        # an awfully simple callback
        def watch_cb(arg, line, who, stamp_sec, stamp_nsec, seq, level, msg):
            print line
            sys.stdout.flush()

        # first do a ceph status
        ret, outbuf, outs = json_command(cluster_handle, prefix='status')
        if ret == -errno.EINVAL:
            # try old mon
            ret, outbuf, outs = send_command(cluster_handle, cmd=['status'])
            # old mon returns status to outs...ick
            if ret == 0:
                outbuf += outs
        if ret:
            print >> sys.stderr, "status query failed: ", outs
            return ret
        print outbuf

        # this instance keeps the watch connection alive, but is
        # otherwise unused
        rados.MonitorLog(cluster_handle, level, watch_cb, 0)

        # loop forever letting watch_cb print lines
        try:
            signal.pause()
        except KeyboardInterrupt:
            # or until ^C, at least
            return 0

    # read input file, if any
    inbuf = ''
    if parsed_args.input_file:
        try:
            with open(parsed_args.input_file, 'r') as f:
                inbuf = f.read()
        except Exception as e:
            print >> sys.stderr, 'Can\'t open input file {0}: {1}'.format(parsed_args.input_file, e)
            return 1

    # prepare output file, if any
    if parsed_args.output_file:
        try:
            outf = open(parsed_args.output_file, 'w')
        except Exception as e:
            print >> sys.stderr, \
                'Can\'t open output file {0}: {1}'.\
                format(parsed_args.output_file, e)
            return 1

    # -s behaves like a command (ceph status).
    if parsed_args.status:
        childargs.insert(0, 'status')

    try:
        target = find_cmd_target(childargs)
    except Exception as e:
        print >> sys.stderr, \
                'error handling command target: {0}'.format(e)
        return 1

    # Repulsive hack to handle tell: lop off 'tell' and target
    # and validate the rest of the command.  'target' is already
    # determined in our callers, so it's ok to remove it here.
    is_tell = False
    if len(childargs) and childargs[0] == 'tell':
        childargs = childargs[2:]
        is_tell = True

    if is_tell:
        if injectargs:
            childargs = injectargs
        if not len(childargs):
            print >> sys.stderr, \
                'Cannot use \'tell\' with interactive mode.', \
                'For an interactive shell,', \
                'please start "{0}" without non-option arguments.'.format(sys.argv[0])
            return errno.EINVAL

    # fetch JSON sigs from command
    # each line contains one command signature (a placeholder name
    # of the form 'cmdNNN' followed by an array of argument descriptors)
    # as part of the validated argument JSON object

    targets = [target]

    if target[1] == '*':
        if target[0] == 'osd':
            targets = [(target[0], o) for o in osdids()]
        elif target[0] == 'mon':
            targets = [(target[0], m) for m in monids()]

    final_ret = 0
    for target in targets:
        # prettify?  prefix output with target, if there was a wildcard used
        prefix = ''
        suffix = ''
        if not parsed_args.output_file and len(targets) > 1:
            prefix = '{0}.{1}: '.format(*target)
            suffix = '\n'

        ret, outbuf, outs = json_command(cluster_handle, target=target,
                                         prefix='get_command_descriptions')
        compat = False
        if ret == -errno.EINVAL:
            # send command to old monitor or OSD
            if verbose:
                print prefix + '{0} to old {1}'.format(' '.join(childargs), target[0])
            compat = True
            if parsed_args.output_format:
                childargs.extend(['--format', parsed_args.output_format])
            ret, outbuf, outs = send_command(cluster_handle, target, childargs,
                                             inbuf)

            if ret == -errno.EINVAL:
                # did we race with a mon upgrade?  try again!
                ret, outbuf, outs = json_command(cluster_handle, target=target,
                                                 prefix='get_command_descriptions')
                if ret == 0:
                    compat = False  # yep, carry on
        if not compat:
            if ret:
                if ret < 0:
                    outs = 'problem getting command descriptions from {0}.{1}'.format(*target)
            else:
                sigdict = parse_json_funcsigs(outbuf, 'cli')

                if parsed_args.completion:
                    return complete(sigdict, childargs, target)

                ret, outbuf, outs = new_style_command(parsed_args, childargs, target,
                                                      sigdict, inbuf, verbose)

                # debug tool: send any successful command *again* to
                # verify that it is idempotent.
                if not ret and 'CEPH_CLI_TEST_DUP_COMMAND' in os.environ:
                    ret, outbuf, outs = new_style_command(parsed_args, childargs, target,
                                                          sigdict, inbuf, verbose)
                    if ret < 0:
                        ret = -ret
                        print >> sys.stderr, prefix + 'Second attempt of previously successful command failed with {0}: {1}'.format(errno.errorcode.get(ret, 'Unknown'), outs)

        if ret < 0:
            ret = -ret
            print >> sys.stderr, prefix + 'Error {0}: {1}'.format(errno.errorcode.get(ret, 'Unknown'), outs)
            if len(targets) > 1:
                final_ret = ret
            else:
                return ret

        # this assumes outs never has useful command output, only status
        if compat:
            if ret == 0:
                # old cli/mon would send status string to stdout on non-error
                print outs
        else:
            if outs:
                print >> sys.stderr, prefix + outs

        if (parsed_args.output_file):
            outf.write(outbuf)
        else:
            # hack: old code printed status line before many json outputs
            # (osd dump, etc.) that consumers know to ignore.  Add blank line
            # to satisfy consumers that skip the first line, but not annoy
            # consumers that don't.
            if parsed_args.output_format and \
               parsed_args.output_format.startswith('json') and \
               not compat:
                sys.stdout.write('\n')

            # if we are prettifying things, normalize newlines.  sigh.
            if suffix != '':
                outbuf = outbuf.rstrip()
            if outbuf != '':
                sys.stdout.write(prefix + outbuf + suffix)

        sys.stdout.flush()

    if (parsed_args.output_file):
        outf.close()

    if final_ret:
        return final_ret

    return 0

if __name__ == '__main__':
    retval = main()
    # shutdown explicitly; Rados() does not
    if cluster_handle:
        cluster_handle.shutdown()
    sys.exit(retval)