ceph-deploy-mon的create函数

ceph-deploy的mon 命令用于管理mon守护进程
其入口函数在E:\ceph-deploy-master\ceph-deploy-master\ceph_deploy\mon.py 中的make函数
@priority(30)
def make(parser):
    """
    Ceph MON Daemon management
    """
    parser.formatter_class = ToggleRawTextHelpFormatter

    mon_parser = parser.add_subparsers(dest='subcommand')
    mon_parser.required = True

    mon_add = mon_parser.add_parser(
        'add',
        help=('R|Add a monitor to an existing cluster:\n'
              '\tceph-deploy mon add node1\n'
              'Or:\n'
              '\tceph-deploy mon add --address 192.168.1.10 node1\n'
              'If the section for the monitor exists and defines a `mon addr` that\n'
              'will be used, otherwise it will fallback by resolving the hostname to an\n'
              'IP. If `--address` is used it will override all other options.')
    )

    mon_destroy = mon_parser.add_parser(
        'destroy',
        help='Completely remove Ceph MON from remote host(s)'
    )
    mon_destroy.add_argument(
        'mon',
        nargs='+',
    )

    parser.set_defaults(
        func=mon,
    )
make函数为mon 添加各种参数，并指定默认的处理函数是mon
def mon(args):
    if args.subcommand == 'create':
        mon_create(args)
    elif args.subcommand == 'add':
        mon_add(args)
    elif args.subcommand == 'destroy':
        mon_destroy(args)
    elif args.subcommand == 'create-initial':
        mon_create_initial(args)
    else:
        LOG.error('subcommand %s not implemented', args.subcommand)
可以看动作mon 总共支持4个子命令，分别是create/add/destroy/create-initial
首先看看create命令
def mon_create(args):
#获取配置文件
    cfg = conf.ceph.load(args)
    if not args.mon:
@如果没有指定mon，则从配置文件中mon_initial_members 作为mon
        args.mon = get_mon_initial_members(args, error_on_empty=True, _cfg=cfg)

    if args.keyrings:
        monitor_keyring = concatenate_keyrings(args)
    else:
#获取ceph.mon.keyring 文件的路径
        keyring_path = '{cluster}.mon.keyring'.format(cluster=args.cluster)
        try:
#读取ceph.mon.keyring文件
            monitor_keyring = files.read_file(keyring_path)
        except IOError:
            LOG.warning('keyring (%s) not found, creating a new one' % keyring_path)
            new_mon_keyring(args)
            monitor_keyring = files.read_file(keyring_path)

    LOG.debug(
        'Deploying mon, cluster %s hosts %s',
        args.cluster,
        ' '.join(args.mon),
        )

    errors = 0
    for (name, host) in mon_hosts(args.mon):
        try:
            # TODO add_bootstrap_peer_hint
            LOG.debug('detecting platform for host %s ...', name)
#获取是哪个发行版，并通过callbacks 检测发行版是否安装了ceph
            distro = hosts.get(
                host,
                username=args.username,
                callbacks=[packages.ceph_is_installed]
            )
            LOG.info('distro info: %s %s %s', distro.name, distro.release, distro.codename)
            rlogger = logging.getLogger(name)

            # ensure remote hostname is good to go
            hostname_is_compatible(distro.conn, rlogger, name)
            rlogger.debug('deploying mon to %s', name)
#调用发行版的mon模块的create函数来新建mon
            distro.mon.create(distro, args, monitor_keyring)

            # tell me the status of the deployed mon
#等待2s后检查前面新建的mon的状态
            time.sleep(2)  # give some room to start
            mon_status(distro.conn, rlogger, name, args)
#获取错误日志写到rlogger
            catch_mon_errors(distro.conn, rlogger, name, cfg, args)
            distro.conn.exit()

        except RuntimeError as e:
            LOG.error(e)
            errors += 1

    if errors:
        raise exc.GenericError('Failed to create %d monitors' % errors)
		

我们以suse为例看看mon.create。路径为E:\ceph-deploy-master\ceph-deploy-master\ceph_deploy\hosts\common.py
def mon_create(distro, args, monitor_keyring):
    hostname = distro.conn.remote_module.shortname()
    logger = distro.conn.logger
    logger.debug('remote hostname: %s' % hostname)
    path = paths.mon.path(args.cluster, hostname)
    uid = distro.conn.remote_module.path_getuid(constants.base_path)
    gid = distro.conn.remote_module.path_getgid(constants.base_path)
    done_path = paths.mon.done(args.cluster, hostname)
    init_path = paths.mon.init(args.cluster, hostname, distro.init)

    conf_data = conf.ceph.load_raw(args)

    # write the configuration file
    distro.conn.remote_module.write_conf(
        args.cluster,
        conf_data,
        args.overwrite_conf,
    )

    # if the mon path does not exist, create it
    distro.conn.remote_module.create_mon_path(path, uid, gid)

    logger.debug('checking for done path: %s' % done_path)
    if not distro.conn.remote_module.path_exists(done_path):
        logger.debug('done path does not exist: %s' % done_path)
        if not distro.conn.remote_module.path_exists(paths.mon.constants.tmp_path):
            logger.info('creating tmp path: %s' % paths.mon.constants.tmp_path)
            distro.conn.remote_module.makedir(paths.mon.constants.tmp_path)
        keyring = paths.mon.keyring(args.cluster, hostname)

        logger.info('creating keyring file: %s' % keyring)
        distro.conn.remote_module.write_monitor_keyring(
            keyring,
            monitor_keyring,
            uid, gid,
        )

        user_args = []
        if uid != 0:
            user_args = user_args + [ '--setuser', str(uid) ]
        if gid != 0:
            user_args = user_args + [ '--setgroup', str(gid) ]
# 重点是通过ceph-mon 这个命令来创建ceph mon
        remoto.process.run(
            distro.conn,
            [
                'ceph-mon',
                '--cluster', args.cluster,
                '--mkfs',
                '-i', hostname,
                '--keyring', keyring,
            ] + user_args
        )

        logger.info('unlinking keyring file %s' % keyring)
        distro.conn.remote_module.unlink(keyring)

    # create the done file
    distro.conn.remote_module.create_done_path(done_path, uid, gid)

    # create init path
    distro.conn.remote_module.create_init_path(init_path, uid, gid)
#启动mon
    # start mon service
    start_mon_service(distro, args.cluster, hostname)