Python fabric模块

fabric是python2.5或者更高的库,可以通过ssh在多个host上批量执行任务.完成系统管理任务.它提供一套基本操作在本地和远程执行shell命令,或者上传下载文件,辅助提供用户输入或终止执行.

下面安装fabric模块有2种方法:

1.使用easy_install(下面是debain5环境)

[email protected]:pshell# apt-get install python-dev (安装Python头文件)

[email protected]:pshell# apt-get install python-setuptools (安装easy_install)

[email protected]:pshell# wget http://peak.telecommunity.com/dist/ez_setup.py

[email protected]:pshell# python ez_setup.py

[email protected]:pshell# easy_install fabric
Searching for fabric
Reading http://pypi.python.org/simple/fabric/
Best match: Fabric 1.6.1
Downloading http://pypi.python.org/packages/source/F/Fabric/Fabric-1.6.1.tar.gz#md5=c318ac3f7011ede0be1ca9a20f435735
Processing Fabric-1.6.1.tar.gz
Running Fabric-1.6.1/setup.py -q bdist_egg --dist-dir /tmp/easy_install-CVuLrs/Fabric-1.6.1/egg-dist-tmp-ZFNoWY
warning: no previously-included files matching '*' found under directory 'docs/_build'
warning: no previously-included files matching '*.pyc' found under directory 'tests'
warning: no previously-included files matching '*.pyo' found under directory 'tests'
zip_safe flag not set; analyzing archive contents...
fabric.version: module references __file__
Adding Fabric 1.6.1 to easy-install.pth file
Installing fab script to /usr/bin
....
Installed /usr/lib/python2.5/site-packages/pycrypto-2.6-py2.5-linux-x86_64.egg
Finished processing dependencies for fabric

2.使用pip(下面使用的是debian7环境)

apt-get install python-pip
pip install fabric
apt-get install python-paramiko

导入模块未报错说明安装成功.

实例:

1.在调用fabric的时候使用命令行参数,-H 指定哪台主机

[email protected]:python# cat fabfile4.py 

#!/usr/bin/env python
#coding=utf-8
from fabric.api import *

def printMem():
      cmd_output = run('free -m')
      print cmd_output

[email protected]:python# fab -H [email protected] printMem -f fabfile4.py
[[email protected]] Executing task 'printMem'
[[email protected]] run: free -m
[[email protected]] Login password for 'root': #提示输入密码
[[email protected]] out:              total       used       free     shared    buffers     cached
[[email protected]] out: Mem:          1005        968         37          0         36        831
[[email protected]] out: -/+ buffers/cache:        100        904
[[email protected]] out: Swap:         1913          0       1913
[[email protected]] out: 

total       used       free     shared    buffers     cached
Mem:          1005        968         37          0         36        831
-/+ buffers/cache:        100        904
Swap:         1913          0       1913

Done.
Disconnecting from 10.1.1.45:22000... done.

2.以上我们需要输入密码才能完成操作,怎样自动执行呢?可以在fabfile4文件中配置HOST.也就是环境变量.

[email protected]:python# vim fabfile.py
#!/usr/bin/env python
#coding=utf-8
from fabric.api import *
from fabric.context_managers import *

env.host_string = '10.1.1.45'
env.port = '22000'             #默认端口22,默认登录用户root
env.password='passwd'

def test1():
    with cd('/home'):
        run('ls -l')

test1()

[email protected]:python# python fabfile.py   #脚本执行
[10.1.1.45] run: ls -l
[10.1.1.45] out: total 8
[10.1.1.45] out: drwxr-xr-x 2 debian debian  4096 2012-08-27 11:54 debian
[10.1.1.45] out: drwxr-xr-x 2 root   nogroup 4096 2013-05-22 18:07 ftp
[10.1.1.45] out: 

[email protected]:python# vim fabfile1.py
#!/usr/bin/env python
#coding=utf-8
from fabric.api import *
from fabric.context_managers import *

env.hosts = ['10.1.6.200','10.1.1.45']
env.port = '22000'
env.password='passwd'

def test1():
    with cd('/home'):  #更改目录
        run('ls -l')

[email protected]:python# fab test1 -f fabfile.py  #使用fab指定任务执行,注意文件后默认跟fabfile.py
[10.1.6.200] Executing task 'test1'
[10.1.6.200] run: ls -l
[10.1.6.200] out: total 24
[10.1.6.200] out: drwxr-xr-x 2 davehe davehe 4096 2013-02-27 10:00 davehe
[10.1.6.200] out: -rw-r--r-- 1 root   root   1990 2013-02-27 09:55 davehe.tar.gz
[10.1.6.200] out: -rw-r--r-- 1 root   root    396 2013-05-17 18:27 rsync_log_130517
[10.1.6.200] out: -rw-r--r-- 1 root   root   7916 2013-05-20 21:04 rsync_log_130520
[10.1.6.200] out: drwxr-xr-x 2 taomee taomee 4096 2013-01-29 04:27 taomee
[10.1.6.200] out: 

[10.1.1.45] Executing task 'test1'
[10.1.1.45] run: ls -l
[10.1.1.45] out: total 8
[10.1.1.45] out: drwxr-xr-x 2 debian debian  4096 2012-08-27 11:54 debian
[10.1.1.45] out: drwxr-xr-x 2 root   nogroup 4096 2013-05-22 18:07 ftp
[10.1.1.45] out: 


Done.
Disconnecting from 10.1.1.45:22000... done.
Disconnecting from 10.1.6.200:22000... done.

3.使用get/put.利用sftp协议上传下载文件

[email protected]:python# cat fabfile1.py

#!/usr/bin/env python
#coding=utf-8
from fabric.api import *
from fabric.colors import *
from fabric.context_managers import *

env.hosts = ['10.1.1.45']
env.port = '22000'
env.password='passwd'

def test1():
    print(red("i'm 201"))
    local('ls -l /tmp')

def test2():
    print (green("i'm get file 45 to 186"))
    get('/home/ftp/a.txt','/tmp/')  #下载
#    put('/tmp/','/home/ftp/')  #上传
    local('ls -l /tmp')   #local运行本地命令


def final():
    execute(test1)
    execute(test2)

[email protected]:python# fab final -f fabfile1.py
[10.1.1.45] Executing task 'final'
[10.1.1.45] Executing task 'test1'
i'm 201
[localhost] local: ls -l /tmp
total 31684
drwxr-xr-x 2 root root     4096 May 13 22:08 bin
drwxr-xr-x 3 root root     4096 May 13 22:08 conf
drwxr-xr-x 6 root root     4096 May 13 22:08 etc
-rwxr-xr-x 1 root root     6797 May 13 22:08 init
-rw-r--r-- 1 root root 32400896 May 13 22:07 initrd.img-3.2.0-4-amd64
drwxr-xr-x 6 root root     4096 May 13 22:08 lib
drwxr-xr-x 2 root root     4096 May 13 22:08 lib64
drwxr-xr-x 2 root root     4096 May 13 22:08 run
drwxr-xr-x 2 root root     4096 May 13 22:08 sbin
drwxr-xr-x 6 root root     4096 May 13 22:08 scripts
[10.1.1.45] Executing task 'test2'
i'm get file 45 to 186
[10.1.1.45] download: /tmp/a.txt <- /home/ftp/a.txt
[localhost] local: ls -l /tmp
total 31688
-rw-r--r-- 1 root root        6 May 29 22:29 a.txt
drwxr-xr-x 2 root root     4096 May 13 22:08 bin
drwxr-xr-x 3 root root     4096 May 13 22:08 conf
drwxr-xr-x 6 root root     4096 May 13 22:08 etc
-rwxr-xr-x 1 root root     6797 May 13 22:08 init
-rw-r--r-- 1 root root 32400896 May 13 22:07 initrd.img-3.2.0-4-amd64
drwxr-xr-x 6 root root     4096 May 13 22:08 lib
drwxr-xr-x 2 root root     4096 May 13 22:08 lib64
drwxr-xr-x 2 root root     4096 May 13 22:08 run
drwxr-xr-x 2 root root     4096 May 13 22:08 sbin
drwxr-xr-x 6 root root     4096 May 13 22:08 scripts

Done.
Disconnecting from 10.1.1.45:22000... done.

上面实例中只列举了几个常用的farbic环境变量.如env.hosts,env.password等,可以不需要交互输入密码.

以下还有常用环境变量以供参考:

exclude_hosts:指定一个主机列表，在fab执行时，忽略列表中的机器

user:ssh使用哪个用户登录远程主机

hosts :全局的host列表

host_string :当fabric连接远程机器执行run、put时，设置的user/host/port等

password:默认ssh连接远程主机密码,也可以是sudo提示输入密码

password:一个字典供内部使用,为每台主机host设置密码,key是主机,value值存放密码

port:设置默认端口

roledefs:使用字典定义角色名字对应的主机ip

roles:一个全局的role列表

from fabric.api import run, roles

env.roledefs = {
    'db': ['db1', 'db2'],
    'web': ['web1', 'web2', 'web3'],
}

@roles('db')
def migrate():
    # Database stuff here.
    pass

@roles('web')
def update():
    # Code updates here.
    pass

fab也可以使用命令设置环境变量,常用命令

-f FABFILE, --fabfile=FABFILE  默认fabfile.py

-H HOSTS, --hosts=HOSTS     env.hosts=hosts

-p PASSWORD, --password=PASSWORD  env.password 

-R ROLES, --roles=ROLES   env.roles

注意定义主机时优先级策略

• Per-task, command-line host lists (fab mytask:host=host1) override absolutely everything else.
• Per-task, decorator-specified host lists (@hosts('host1')) override the env variables.
• Globally specified host lists set in the fabfile (env.hosts = ['host1']) can override such lists set on the command-line, but only if you’re not careful (or want them to.)
• Globally specified host lists set on the command-line (--hosts=host1) will initialize the envvariables, but that’s it.

附录:

http://docs.fabfile.org/en/1.6/index.html#