ansible/bin/ansible-pull

#!/usr/bin/env python

# (c) 2012, Stephen Fromm <sfromm@gmail.com>
#
# Ansible 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 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.
#
# ansible-pull is a script that runs ansible in local mode
# after checking out a playbooks directory from source repo.  There is an
# example playbook to bootstrap this script in the examples/ dir which
# installs ansible and sets it up to run on cron.

# usage:
#   ansible-pull -d /var/lib/ansible \
#                -U http://example.net/content.git [-C production] \
#                [path/playbook.yml]
#
# the -d and -U arguments are required; the -C argument is optional.
#
# ansible-pull accepts an optional argument to specify a playbook
# location underneath the workdir and then searches the source repo
# for playbooks in the following order, stopping at the first match:
#
# 1. $workdir/path/playbook.yml, if specified
# 2. $workdir/$fqdn.yml
# 3. $workdir/$hostname.yml
# 4. $workdir/local.yml
#
# the source repo must contain at least one of these playbooks.

import os
import shutil
import subprocess
import sys
import datetime
import socket
from ansible import utils
import shlex
import select

DEFAULT_REPO_TYPE = 'git'
DEFAULT_PLAYBOOK = 'local.yml'
PLAYBOOK_ERRORS = {1: 'File does not exist',
                    2: 'File is not readable'}


def _run_verbose(cmd):
    cmdargs = shlex.split(cmd)
    p = subprocess.Popen(cmdargs, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    
    stdout = ''
    stderr = ''
    rpipes = [p.stdout, p.stderr]
    while True:
        rfd, wfd, efd = select.select(rpipes, [], rpipes, 1)

        if p.stdout in rfd:
            dat = os.read(p.stdout.fileno(), 100)
            sys.stdout.write(dat)
            stdout += dat
            if dat == '':
                rpipes.remove(p.stdout)
        if p.stderr in rfd:
            dat = os.read(p.stderr.fileno(), 100)
            stderr += dat
            sys.stdout.write(dat)
            if dat == '':
                rpipes.remove(p.stderr)
        # only break out if we've emptied the pipes, or there is nothing to
        # read from and the process has finished.
        if (not rpipes or not rfd) and p.poll() is not None:
            break
        # Calling wait while there are still pipes to read can cause a lock
        elif not rpipes and p.poll() == None:
            p.wait()

    return p.returncode, stdout

def _run(cmd):
    print >>sys.stderr, "Running: '%s'" % cmd
    cmd = subprocess.Popen(cmd, shell=True,
                           stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    (out, err) = cmd.communicate()
    print out
    if cmd.returncode != 0:
        print >>sys.stderr, err
    return cmd.returncode, out


def try_playbook(path):
    if not os.path.exists(path):
        return 1
    if not os.access(path, os.R_OK):
        return 2
    return 0


def select_playbook(path, args):
    playbook = None
    if len(args) > 0 and args[0] is not None:
        playbook = "%s/%s" % (path, args[0])
        rc = try_playbook(playbook)
        if rc != 0:
            print >>sys.stderr, "%s: %s" % (playbook, PLAYBOOK_ERRORS[rc])
            return None
        return playbook
    else:
        fqdn = socket.getfqdn()
        hostpb = "%s/%s.yml" % (path, fqdn)
        shorthostpb = "%s/%s.yml" % (path, fqdn.split('.')[0])
        localpb = "%s/%s" % (path, DEFAULT_PLAYBOOK)
        errors = []
        for pb in [hostpb, shorthostpb, localpb]:
            rc = try_playbook(pb)
            if rc == 0:
                playbook = pb
                break
            else:
                errors.append("%s: %s" % (pb, PLAYBOOK_ERRORS[rc]))
        if playbook is None:
            print >>sys.stderr, "\n".join(errors)
        return playbook


def main(args):
    """ Set up and run a local playbook """
    usage = "%prog [options] [playbook.yml]"
    parser = utils.SortedOptParser(usage=usage)
    parser.add_option('-v', '--verbose', default=False, action='store_true',
                      help='Print the ansible-playbook output while running')
    parser.add_option('--purge', default=False, action='store_true',
                      help='purge checkout after playbook run')
    parser.add_option('-o', '--only-if-changed', dest='ifchanged', default=False, action='store_true',
                      help='only run the playbook if the repository has been updated')
    parser.add_option('-f', '--force', dest='force', default=False,
                      action='store_true',
                      help='run the playbook even if the repository could '
                           'not be updated')
    parser.add_option('-d', '--directory', dest='dest', default=None,
                      help='directory to checkout repository to')
    parser.add_option('-U', '--url', dest='url', default=None,
                      help='URL of the playbook repository')
    parser.add_option('-C', '--checkout', dest='checkout',
                      help='branch/tag/commit to checkout.  '
                      'Defaults to behavior of repository module.')
    parser.add_option('-i', '--inventory-file', dest='inventory',
                      help="location of the inventory host file")
    parser.add_option('-m', '--module-name', dest='module_name',
                      default=DEFAULT_REPO_TYPE,
                      help='Module name used to check out repository.  '
                      'Default is %s.' % DEFAULT_REPO_TYPE)
    options, args = parser.parse_args(args)

    hostname = socket.getfqdn()
    if not options.dest:
        # use a hostname dependent directory, in case of $HOME on nfs
        options.dest = utils.prepare_writeable_dir('~/.ansible/pull/%s' % hostname)

    options.dest = os.path.abspath(options.dest)

    if not options.url:
        parser.error("URL for repository not specified, use -h for help")
        return 1

    now = datetime.datetime.now()
    print >>sys.stderr, now.strftime("Starting ansible-pull at %F %T")

    inv_opts = 'localhost,'
    limit_opts = 'localhost:%s:127.0.0.1' % hostname
    if not options.verbose:
        base_opts = '-c local --limit "%s"' % limit_opts
    else:
        base_opts = '-vvvv -c local --limit "%s"' % limit_opts
    repo_opts = "name=%s dest=%s" % (options.url, options.dest)
    if options.checkout:
        repo_opts += ' version=%s' % options.checkout
    path = utils.plugins.module_finder.find_plugin(options.module_name)
    if path is None:
        sys.stderr.write("module '%s' not found.\n" % options.module_name)
        return 1
    cmd = 'ansible all -i "%s" %s -m %s -a "%s"' % (
            inv_opts, base_opts, options.module_name, repo_opts
            )
    rc, out = _run(cmd)
    if rc != 0:
        if options.force:
            print "Unable to update repository. Continuing with (forced) run of playbook."
        else:
            return rc
    elif options.ifchanged and '"changed": true' not in out:
        print "Repository has not changed, quitting."
        return 0

    playbook = select_playbook(options.dest, args)

    if playbook is None:
        print >>sys.stderr, "Could not find a playbook to run."
        return 1

    cmd = 'ansible-playbook %s %s' % (base_opts, playbook)
    if options.inventory:
        cmd += ' -i "%s"' % options.inventory
    os.chdir(options.dest)
    if not options.verbose:
        rc, out = _run(cmd)
    else:
        rc, out = _run_verbose(cmd)

    if options.purge:
        os.chdir('/')
        try:
            shutil.rmtree(options.dest)
        except Exception, e:
            print >>sys.stderr, "Failed to remove %s: %s" % (options.dest, str(e))

    return rc

if __name__ == '__main__':
    try:
        sys.exit(main(sys.argv[1:]))
    except KeyboardInterrupt, e:
        print >>sys.stderr, "Exit on user request.\n"
        sys.exit(1)