python 远程执行代码 fabr

 fabric应用:
               1、fab -H 172.23.177.40,172.23.177.41 host_type
               2、fab host_type check_ver
               3、role： 当client较多时可以定义角色，然后按角色进行操作。
                    #!/usr/bin/pyhton
                    from fabric.api import *
                    env.user = 'root'
                    env.passWord = 'vagrant'
                    env.roledefs = {
                         'WEB': ['172.23.177.41','172.23.177.43'],
                         'dns': ['172.23.177.46','177.23.177.73']
                    }
                    def test():
                        run('uname -a')
               run:
                    fab -R web test
               result:
                    [172.23.177.41] Executing task 'test'
                    [172.23.177.41] run: uname -a
                    [172.23.177.41] out: linux salt-master 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
                    [172.23.177.41] out:
                    [172.23.177.43] Executing task 'test'
                    [172.23.177.43] run: uname -a
                    [172.23.177.43] out: Linux salt-miNIOn-3 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
                    [172.23.177.43] out:
                    Done.
                    Disconnecting from 172.23.177.43... done.
                    Disconnecting from 172.23.177.41... done.
                    #从结果可以看到，fab只执行了属于web组的client。
               4、extend属性
                    from fabric.api import env, run
                    env.hosts.extend(['host3', 'host4'])
                    def test():
                        run('uname -r')
                    When this fabfile is run as fab -H host1,host2 mytask, env.hosts will then contain ['host1', 'host2', 'host3', 'host4'] at the time that mytask is executed.
               5、fabfile中没有定义client，可以在命令行中指定
                    fab mytask:hosts='172.23.177.41;172.23.177.46'
               6、使用task方式：
                    from fabric.api import hosts, run
                    @hosts('172.23.177.41', '172.23.188.46')
                    def test():
                        run('uname -r')
                    或者：
                    my_hosts = ('172.23.177.41', '172.23.177.46')
                    @hosts(my_hosts)
                    def test():
                         run('uname -r')
               run:
                    fab test
               resule: 从结果中可以看到，fab只执行了task定义的test部分
                    [172.23.177.41] Executing task 'test'
                    [172.23.177.41] run: uname -a
                    [172.23.177.41] out: Linux salt-master 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
                    [172.23.177.41] out:
                    [172.23.177.46] Executing task 'test'
                    [172.23.177.46] run: uname -a
                    [172.23.177.46] out: Linux salt-minion-1 2.6.32-358.23.2.el6.x86_64 #1 SMP Wed Oct 16 18:37:12 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux
                    [172.23.177.46] out:
                    Done.
                    Disconnecting from 172.23.177.41... done.
                    Disconnecting from 172.23.177.46... done.
               7、综合应用：
                    from fabric.api import env, hosts, roles, run
                    env.roledefs = {'role1': ['b', 'c']}
                    @hosts('a', 'b')
                    @roles('role1')
                    def test():
                        run('uname -r')
               8、遇到主机不可达的情况，可以使用--skip-bad-hosts参数，这样就会跳过不存在或有问题的client，而执行其他的client，从返回结果中可以排除那些是有问题的client，进而在进行处理
                    fab --skip-bad-hosts test
                    node:
                    my_hosts = ('172.23.177.41','172.23.177.40','172.23.177.46')
                    @hosts(my_hosts)
                    def test():
                        run('uname -a')